I'm new to programming java and I'm attempting to find out why my code keeps giving me the error java.lang.NullPointerException. It's supposed to take 6 points, and create 2 triangles.  MAIN CLASS  public class Themain{   public static void main (String[] args){     Point pointone = new Point(1,2);     Point pointtwo = new Point(3,4);     Point pointthree = new Point(0,5);      Point josh = new Point(1,2);     Point abby = new Point(3,4);     Point trevor = new Point(0,6);       Triangle2D triangleone = new Triangle2D();     Triangle2D triangletwo = new Triangle2D();      triangleone.setPoint1(pointone);     triangleone.setPoint2(pointtwo);     triangleone.setPoint3(pointthree);      triangletwo.setPoint1(josh);     triangletwo.setPoint2(abby);     triangletwo.setPoint3(trevor);       } }   TRIANGLE CLASS    public class Triangle2D{    Point p1;   Point p2;   Point p3;   //no args constructor   public Triangle2D(){      }    //set point one    public void setPoint1(Point p){     p1.setXPos(p.getXPos());     p1.setYPos(p.getYPos());   }   //set point two   public void setPoint2(Point p){     p2.setXPos(p.getXPos());     p2.setYPos(p.getYPos());   }  //set point three   public void setPoint3(Point p){     p3.setXPos(p.getXPos());     p3.setYPos(p.getYPos());   }    //get point one    public Point getPoint1(){     return(p1);   }  }   POINT CLASS   public class Point{    int x;   int y;     //args constructor   public Point(int x, int y){     this.x = x;     this.y = y;   }    //get the x-coordiante   public int getXPos(){     return x;   }    //set the x-coordinate   public void setXPos(int x){     this.x = x;   }     //get the y-coordinate   public int getYPos(){     return y;   }    //set the y-coordinate   public void setYPos(int y){     this.y = y;   }    //is equals method    public boolean isEquals(Point t){     return(this.x == t.x && this.y == t.y);   }  }   I'm not sure why it's giving my the null error. The real code is much longer than this but I have take the section that was causing the error and I put it into this file. I'm mostly writing this because stack overflow says there is too much code. If someone could help me understand why this error appears it would be greatly appreciated.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm just here to ask which file directory I can find my desktop background wallpapers in 14.04 so I can copy them onto a USB and take them over to my Windows 8 PC so I can use them there.

Please see the picture below. Where are the Unity desktop wallpapers located?


is there any way to recover from a ORA-00257: archiver error?  The archiver disks broke, but DB continue operation 2 sequences more. I have no access to the archiver disk anymore   SQL> archive log list Database log mode              Archive Mode Automatic archival             Enabled Archive destination            /drbak/arch/terdb/pro/va Oldest online log sequence     46612 Next log sequence to archive   46612 Current log sequence           46614     SQL> show parameter db_recovery_file_dest; NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ db_recovery_file_dest                string db_recovery_file_dest_size           big integer 50000M   SQL> SELECT * FROM V$RECOVERY_FILE_DEST; NAME -------------------------------------------------------------------------------- SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES ----------- ---------- ----------------- ---------------   5.2429E+10          0                 0               0

I ran into this error earlier today and requested that the extra logs be purged from the server. It was done but it still claims that there isn't any room. Is there a way to notify the server that it has more room than it thinks?


I noticed that not a lot of authors of math books don't use the $\leadsto$ to denote the next step. As far as I understand it, that is supposed to mean "the next step of the proof is". Instead, I notice that they use $=$ to mean the same thing, or also $\implies$ or $\iff$. Which symbol is the most appropriate for stating the next step? Can we use $\implies$ and $\leadsto$ interchangeably? Is this accepted in formal proofs?

In order to write a scientific paper, I would like to use the symbol     \rightsquigarrow or \leadsto   which look as: $\rightsquigarrow$ or $\leadsto$  I'm wondering about the usual meaning and use of this symbol.  Thanks in advance.


The Rogue can sneak attack if another enemy of the target is within 5 feet of it.  What constitutes being an enemy - Hostile intent or hostile actions or just being a passive ally?  An ally of the rogue has the Sanctuary spell up and is within 5 feet of the enemy. The Sanctuary spell continues as long as the warded ally does not attack or casts an attack spell (and maintains concentration). Assuming the warded ally does not attack, would it be considered an enemy for enabling the rogue's sneak attack? An ally of the rogue has Gaseous Form active and is within 5 feet of the enemy. Gaseous Form does not allow the ally to attack.  Does this enable sneak attack? What if the ally is a warlock with Cloak of Flies active and damaging the enemy?

Volo's Guide to Monsters says that you may play an  character, which gives you the following trait,  (p. 120):  Aggressive. As a bonus action, you can move up to your speed toward an enemy of your choice that you can see or hear.  My question is: what can be considered as an enemy for this trait to apply?  Anything I want Any living creature, including non-hostile ones Only creatures that are hostile to me (actual enemies)  For example, can I choose a tree as my enemy, justifying it by a "Me find tree insult my race, me hate tree, me ANGRY!", and then bonus-move toward said tree?


I am looking for a more elegant term to replace 'playgirl'.  Playgirl (n); a woman who pursues a life of pleasure without responsibility or attachments, especially one who is of comfortable means.  The word should be suitable to replace 'playboy' in, for example;      "Genius, billionaire, playboy, philanthropist” line in by Ironman.

I am looking for a word or expression to describe those ladies, usually high society ladies, whose main aim in life is to find a good match for marriage and whose main activity is organising lunches or dinners for relatives and friends often to raise money for some non-profit organisation?


As soon as I click the "2" on my pagination links I get a 404-error. The url correctly changes to http://mysite.com/?paged=2  <?php /**  * The loop that displays the posts.  */ ?>
 <?php      $args = array(         'post_type' => array('post', 'wr_raffle'),         'posts_per_page' => 4,         'order' => 'DESC',         'paged' => (get_query_var('page')) ? get_query_var('page') : 1,     );      $loop = new WP_Query( $args );     while ( $loop->have_posts() ) : $loop->the_post(); ?>
         <article id="post-<?php the_ID(); ?>" <?php post_class('wrapper'); ?>>
<a href="<?php the_permalink(); ?>"><?php the_title(); ?>

<?php the_excerpt(); ?>

          <?php endif; ?>      <?php      endwhile;     wp_reset_postdata();  ?>

 <?php     $endsize = $midsize = 1;     $type = 'plain';     $loop->query_vars['paged'] > 1 ? $current = $loop->query_vars['paged'] : $current = 1;      // Sanitize input argument values     if ( ! in_array( $type, array( 'plain', 'list', 'array' ) ) ) $type = 'plain';     $endsize = (int) $endsize;     $midsize = (int) $midsize;      // Setup argument array for paginate_links()     $pagination = array(         //'base'          => @add_query_arg('paged','%#%'),         'total'         => $loop->max_num_pages,         'current'       => $current,         'show_all'      => false,         'end_size'      => $endsize,         'mid_size'      => $midsize,         'type'          => $type,         'prev_next'     => false,         //'paged'         => $loop->query_vars['paged']     );      echo paginate_links( $pagination ); ?>
   What am I doing wrong here?  I already refreshed my permalinks. Didn't work.

I have added a custom/secondary query to a template file/custom page template; how can I make WordPress use my custom query for pagination, instead of using the main query loop's pagination?  Addendum  I have modified the main loop query via . Why isn't pagination working, and how do I fix it?


Just bought a Nikkor 18-140 G DX VRm and am a bit confused regarding the naming.   I understand that VR stands for Vibration Reduction, but what does the inclusion of "m" in VRm mean?  Also, what does the "G" stand for?

When looking at a lens name, there are a lot acronyms describing its features (often specific to the manufacturer).   Examples, Nikon: Nikon AF-S DX 16-85mm VR f/3.5-5.6G IF-ED Nikon AF-I 600mm f/4D IF-ED Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED    Examples, Canon: Canon EF 85mm f1.2L USM Mark II Canon 70-300mm f/4.5-f/5.6 DO IS    Examples, Sigma: Sigma 150mm F2.8 EX APO DG HSM Macro Sigma 70-200mm F2.8 EX DG OS HSM Sigma 50-150mm F2.8 EX DC APO HSM II    How do I decipher these lens codes from different manufacturers?


What is the reason/intention behind not allowing unregistered users to sort questions by categories like 'votes', 'active' etc. ? Questions are sorted by only the 'newest' type of sort.  I visit many SE sites and it is really not useful if I create an account only to visit once and never use it again.

I think this is platform wide (all SE sites).   Logout Choose a tag, eg.  on SO Try to sort questions by something other than newest   No matter what sorting is chosen, questions are sorted by newest


Let $\xi$ is $U(0, 1)$, $\nu$ is $U(0, 1)$. What type of distribution is $g = \frac{\xi}{\nu}$? I have build logarithm of $g$, here is the plot but it seems like it is not normal distribution:

Suppose $x_1, x_2$ are IDD random variables uniformly distributed on the interval $(0,1)$.  What is the pdf of the quotient $x_2 / x_1$?


It's straightforward to realise that the permissions of a file are not relevant to the ability to delete that file. The ability to modify the directory listing is controlled by the directory's permissions.  However, for years I have believed that the purpose of the write permission was to allow modification of the directory, and the execute permission is for 'search' - listing files, or changing into the directory.  Today I discovered that one cannot rm a file in a directory unless both the write and execute bits are set. In fact, without execute set, write appears almost useless.  $ tree foo/ foo/ └── file_to_delete  0 directories, 1 file $ chmod -x foo $ ls -ld foo drw-rw-r-- 2 ire_and_curses users 4096 Sep 18 22:08 foo/ $ rm foo/file_to_delete  rm: cannot remove ‘foo/file_to_delete’: Permission denied $ chmod +x foo/ $ rm foo/file_to_delete  $ tree foo/ foo/  0 directories, 0 files $   I find this behaviour pretty surprising. For directories, what is the reason that execute is required to make write useful in practice?

In fact, I would like to ask more general question -- "what does write permission for a directory allow you to do exactly?" -- but let's approach it with a concrete example. It is a long question, if you are in a hurry read the bold -- it should cover the main part. Different sources (, , ) say something similar to the following on the directory permissions:  r, read -- reading of the directory's content (filenames inside) w, write -- changing the directory's attributes (e.g. modification time) and creating/renaming/removing entries inside x, search -- accessing files inside, you have access to the inode of the file, hence you can reach it's actual content  My problem is with the description of w. What directory's attributes does it give you access to? I cannot create/rename/remove a file inside a directory with only write permission: I make a directory (tdir/) and a file inside (afile), chmod -x-r tdir/, mv tdir/afile tdir/af, rm tdir/afile, touch tdir/newfile -- all fail with permission denial, unless I set x permission to the directory as well. And x alone doesn't give you the permission to create/rename/remove files inside the directory. In order to do that you need both x and w. But touch tdir does change the modification time of the directory with w only. I would rephrase the sources above this way for the compliance with the issue: a directory's r allows you to see the filenames inside, but no access to the actual file (to the inode); x gives you access to the inodes of the files (which means you can see their permissions and, according to it, have access to the contents), but you still cannot change anything in the directory; directory is actually some sort of a file and to change something in it you need the w permission. Thus, when you are changing something in the directory you need w permission. If your change requires inodes of the files in the directory -- you need x as well. It explains why you cannot remove a file inside a directory with w only: when removing a file you need to reduce the link count of the inode by 1 -- you need to know the inode -- thus you need x for the directory. But why do you need x for creating (you could ask the system to create a file without exposing the inode?) and renaming/moving the file (when you move a file you don't change it in any way, you only change the records inside the directories and their inode counts?)? Maybe it is just an implementation thing? I.e. indeed you don't need the inode for renaming/creating files -- you need only filenames and w permission; but inode and filename constitute one record in the directory; thus changing the filenames = changing the records = kind of accessing the inodes. And also what attributes do directories have besides modification time, permissions and files records? What else in the directory can you change with w only?


Magic wands doesn't work.  Tried using GIMP and zooming in to add to alpha channels but there must be a better way?

I have some jpg images and I need for each of them to have a transparent background.  I have GIMP as a graphic tool.   I need to put them in a web page and I need to see just the main element and have a transparent background.


I have 2 divs. One inside of another. The one on the outside has a width and height of 500px, and the one on the inside have a width of auto. I'm trying to center the div on the inside, but I'm also trying to get the width of it to be auto. It's not adjusting the width to auto, and instead it's spanning the entire 500px of the outer div. I'm not sure what I did wrong, so please take a look at my code:

 Inner

Best way to center a <div> element on a page both vertically and horizontally?  I know that margin-left: auto; margin-right: auto; will center on the horizontal, but what is the best way to do it vertically, too?


I am not a statistician, but am working a proof for the upper bound of an expression which contains the variance of a variable which obtains its values from a closed interval, [0,1]. I have seen in several places (mostly forums and web pages) the result that $\text{Var}(X)\le \frac{(b-a)^2}{4}$ for $a\le X\le b$. I would like to use, and cite, this result but am having an unusually difficult time finding a solid reference. Could someone here recommend one for me?

Suppose that a random variable has a lower and an upper bound [0,1]. How to compute the variance of such a variable?


My issue Usually when using percentages inside a margin property the browser uses the width of the nearest positioned ancestor as reference length. However I'd like to set the margins of my element relative to its parent's height. Is that somehow possible? Or am I stuck with a JavaScript solution? An example Specifically I'd like the following:   .child {   height: 1em;   width: 1em;   background: red;   display: inline-block;   margin: calc((100% - 1em) / 2);   /* margin: calc((5em - 1em) / 2); In absolute units */   /* margin-sizing: height; If only there was some magical property like this... */ } .container {   background: green;   height: 5em;   width: 15em;   position: relative; }

   Something
    To look like this:  I know that I could use absolute units in the example above. However I may not always know the exact height of the parent in a more complex or dynamic example. And I'd like to avoid JavaScript for this. Edit I should clarify something. My end goal is that the red div in the example above is centered vertically but also has the same distance to the left as it has to the top/bottom. Obviously I'm not bound to specifically use the margin properties. But the outcome of your solution should be the same.

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


How can I make this rainbow looking iridescent yellow chromate plating found on metals?

Is it possible to create an  shader in Cycles? Specifically for something like , , , etc..


My code  def tripleAll(nums):     for trip in [nums]:         new = trip * 3         print(new)   Then I would call the function with multiple numbers, like so.   tripleAll(3, 6, 7)   But, when I do this, it says it can only take one positional argument. How can I make it so it takes multiple positional arguments?

In the following method definitions, what does the * and ** do for param2?  def foo(param1, *param2): def bar(param1, **param2):


I just saw this following usage of sql prepare statement and was wondering if this would actually prevent sql injection to occur.  $sql= "Select * from mytable where id =" . $id; $stmt = $con->prepare($sql); $stmt->execute();   By not using the parameterized variables for $id to provide the value later and avoid appending the value directly, I was wondering if this provides enough protection against sql injection?  Thanks.

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


What is a regular expression to validate only work email addresses in JavaScript (declining free email services such as Gmail, Yahoo, Outlook.)?  I have written the pattern = /^[^ ]+@[^ ]+.[a-z]{2,3}$/; to validate free email addresses but I don't know how to validate only work emails  Here's my code:  // validate email address var email = document.getElementById('email');  function validateEmail() {   var emailValue = document.getElementById('email').value;   var pattern = /^[^ ]+@[^ ]+\.[a-z]{2,3}$/;   if (emailValue.match(pattern)) {     email.classList.remove("is-invalid");   } else {     email.classList.add("is-invalid");   } }  email.addEventListener('keydown', validateEmail);

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


I can't get this WFS to work. I tried to stick to the OL-WFS examples - no luck.  let vectorLayer = new ol.source.Vector({   format: new ol.format.GML(),   url: function(extent) {     return 'https://geodienste.hamburg.de/HH_WFS_Statistik_Stadtteile_Wahlergebnisse' +       '?version=1.1.0&request=GetFeature&typename=Statistik_Stadtteile_Wahlergebnisse:Buergerschaftswahl_15.02.2015_-_Wahlbeteiligung_in_Prozent;   },   strategy: ol.loadingstrategy.bbox });  this.featureLayer = vectorLayer;  return new ol.layer.Vector({   source: vectorLayer,   style: new ol.style.Style({     stroke: new ol.style.Stroke({       color: 'rgba(0, 0, 255, 1.0)',       width: 2     })   }) });   This query returns 1.5mb of data - but nothing gets displayed. I also tried the same with this format:  new ol.format.WFS({gmlFormat: ol.format.GML2()})   As well as new ol.format.GML 2 & 3 - no luck. And I tried it with this line of code at the end of the url:  '&bbox=' + extent.join(',') + ',EPSG:6.9:25832'   If I add this (as seems to be recommended in the OL examples) the 1.5mb of data is not returned. It should be a very simple thing to include this data in an OL map!

I am building a web application with OpenLayers that contains a map that allows insert, edit and remove points, my map is now using “EPSG:4326" projection.  I have shapefiles and xlsx files that contain polygons and points that I need to insert as layer in the map.  The problem is that the shapefiles use EPSG:2309 projection, this is Israel tm grid projection that OpenLayers doesn't recognize.  How do I transfer these points/polygons to the EPSG:4326 projection?  I found this:  But I don't know if its can be helpful, or how...


I saw the binomial theorem in some 11th grade book in my library. It was proved by induction. But there was no derivation of it. I do not like to memorize it. So I'm hoping someone can show me a derivation for it and give hint for another way to derive it. It would be great if you try to use high school mathematical tools if possible, so I can understand it.  $$ (x+y)^{n}=\sum _{k=0}^{n}{n \choose k}x^{n-k}y^{k}=\sum _{k=0}^{n}{n \choose k}x^{k}y^{n-k}. $$

I am trying to work through the proof I understand it until on this website  :  Pascal's identity does not apply for $k = 0$ or for $k = n$. In our sum, this means we need to split out the $j = 0$ and $j = k + 1$ terms before applying Pascal's identity.  Why does k=o and k=n correspond to $j=0$ and $j=k+1$?  Now we have the problem of matching the two sums from the left side with the two from the right side. First, notice that the out front on the right side can be thought of as the $j = 0$ term in the first sum. Next, the y $k+1$ out front on the right side can be thought of as the $j = k + 1$ term in the second sum.   Why can you think of these terms equaling $j=0$ in the first sum, why not for the second sum? And the same for $j=k+1$?


Consider a linear regression model: $Y_i = \beta_1 A_i + \beta_2 B_i + u_i$ where all variables are assumed to have mean 0, and $A_{i}$ is distributed independently of both $B_{i}$ and $u_{i}$, but $B_{i}$ and $u_{i}$ might be correlated.   I want to show that the OLS estimator $\widehat{\beta}_1$ is consistent but $\widehat{\beta}_2$ might not be due to the correlation. So I'm deducing the formula for the OLS estimators and this is what I got: $$\widehat{\beta}_1 = \left(\sum A_i A_i'\right)^{-1} \left(\sum A_iY_i\right)$$ and $$\widehat{\beta}_2 = \left(\sum B_i B_i'\right)^{-1} \left(\sum B_i Y_i \right).$$ Is this formula correct? Can any one give me some hint on the problem?  Any help is appreciated, thanks in advance!

In An Introduction to Statistical Learning (James et al.), in section 3.7 exercise 5, it states that the formula for $\hat{\beta}_1$ assuming linear regression without an intercept is  $$\hat{\beta}_1 = \dfrac{\displaystyle\sum\limits_{i=1}^{n}x_iy_i}{\displaystyle \sum\limits_{i=1}^{n}x_i^2}\text{,}$$ where $\hat{\beta}_0 = \bar{y}-\hat{\beta}_1\bar{x}$ and $\hat{\beta}_1 = \dfrac{\displaystyle S_{xy}}{S_{xx}}$ are the usual estimates under OLS for simple linear regression ($S_{xy} = \displaystyle\sum\limits_{i=1}^{n}(x_i - \bar{x})(y_i - \bar{y})$).  This is not the actual exercise; I am merely wondering how to derive the equation. Without using matrix algebra, how do I derive it?   My attempt: with $\hat{\beta}_0 = 0$, we have $\hat{\beta}_1 = \dfrac{\bar{y}}{\bar{x}} = \dfrac{S_{xy}}{S_{xx}}$.  After some algebra, it can be shown that $\displaystyle S_{xy} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}\bar{y}$ and $\displaystyle S_{xx} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}^2$. From here, I'm stuck.


I had a friendly discussion with someone about closed form solutions. They contended that the backpropagation algorithm used in calculating the gradients of deep neural networks can't be called a closed form expression in itself, though it is computing a closed form and can be easily converted to one. I pointed them to the  which says -      "In mathematics, a closed-form expression is a mathematical expression that can be evaluated in a finite number of operations. It may contain constants, variables, certain "well-known" operations (e.g., + − × ÷), and functions (e.g., nth root, exponent, logarithm, trigonometric functions, and inverse hyperbolic functions), but usually no limit."   On the one hand, backpropagation can be completed in a finite number of steps. But the next question becomes, is it a "Mathematical expression".   From the , it isn't clear if function composition should be an operation that qualifies.   For me, backpropagation should certainly be qualified as a "closed form solution" but I can't come up with a water-tight argument for why.  Also, other examples came up in the discussion. Let's say I have an algorithm for finding the smallest prime number larger than some integer. This involves checking each number greater than that integer and stopping when I find a prime. This algorithm can be completed in a finite number of steps and calculates the solution exactly. But can we say there is "no Mathematical expression" here and hence no closed form?     EDIT: My question is different from the linked question since it focuses on these two cases in particular. The first one being backpropagation for deep neural networks. This basically involves the following:  In general we get a loss function that looks like - $L = f(g(h(x)))$ and then we take the derivative and get - $L' = f'(g(h(x))g'(h(x))h'(x)$. The argument being that because we calculate $h(x)$ separately and then substitute it, this is not a closed form.  The second example being the algorithm for finding the smallest prime number larger than an integer.

This is motivated by  and the fact that I have no access to Timothy Chow's paper  indicated there by Qiaochu Yuan.  If an equation $f(x)=0$ has no closed form solution, what does it normally mean? Added: $f$ may depend (and normally does) on parameters.   To me this is equivalent to say that one cannot solve it for $x$ in the sense that there is no elementary expression $g(c_{1},c_{2},\ldots ,c_{p})$ consisting only of a finite number of polynomials, rational functions, roots, exponentials, logarithmic and trigonometric functions, absolute values, integer and fractional parts, such that   $f(g(c_{1},c_{2},\ldots ,c_{p}))=0$.


Do plants that lose their leaves (i.e., deciduous plants) do so because of external conditions (e.g., drought, cold), or because of an internal process?  Another way of looking at it: if you take a deciduous plant that loses its leaves during cold winters with long nights (e.g., Canada), and plant it in an environment where it is always warm and sunny (i.e., at the equator), would this plant continue to shed its leaves and re-grow them according to the seasons in Canada, or would it behave as an evergreen instead?

I've been looking around and cannot find a definite answer on what it is that tells trees to change their metabolism and drop leaves. I see that such activity is called .  What interests me are the specific mechanisms by which a tree knows that it's time to drop leaves. Is it photoperiod shortening (day duration?) Is it temperature changing metabolism? Is it build up of some toxic compound?  Thank you for your input!


I am making a log-in application with java swing, specifically with Eclipse IDE Extension's where it makes a source code out of a visual design that is made, I don't have any errors on my code noticed by the IDE but I got an error message saying java.lang.NullPointerException     at me.garbage.Logger.initialize(UwULogger.java:46)     at me.garbage.Logger.<init>(UwULogger.java:39)     at me.garbage.Logger$1.run(UwULogger.java:26)     at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)     at java.awt.EventQueue.access$500(EventQueue.java:97)     at java.awt.EventQueue$3.run(EventQueue.java:709)     at java.awt.EventQueue$3.run(EventQueue.java:703)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)     at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)     at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)  The extension's name is WindowBuilder 1.9.5, I'm using J8.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


How can I remove the word separation in table of contents, please have a look at the image. I knwo I can do it with \chapter[<ToC entry>]{<body entry>}, but I need a solution in the preambel.  \documentclass[10pt,final]{scrbook} \usepackage{titletoc} % modify toc title \usepackage{lipsum} % dummy text \usepackage{anyfontsize} % change fontsize   \usepackage{tocloft} % design toc \usepackage{framed, xcolor} \usepackage[english,ngerman]{babel} \usepackage[latin1]{inputenc} \usepackage[T1]{fontenc} \usepackage{times} \usepackage{helvet} \usepackage{endnotes} \usepackage{titlesec}  %%% Change the title of toc %%% Change "Contents" size \small, \huge, \Large,...  \addto\captionsngerman{\renewcommand{\contentsname}{\normalfont\slshape\large{Contents}}}  % section itshape \titleformat*{\section}{\itshape} \titleformat*{\subsection}{\itshape} %\titleformat*{\tableofcontents}{\itshape}  % Spacing between section and text % Syntax: \titlespacing*{<command>}{<left>}{<before-sep>}{<after-sep>} \titlespacing*{\subsection}{0cm}{0.84cm}{0.42cm}  \titlespacing*{\section}{0cm}{0.84cm}{0.42cm}  % Spacing between chapter and author  \titlespacing*{\chapter}{0cm}{0.84cm}{0.84cm}  % Spacing between chapterAndAuthor and section (?) %\titlespacing*{\chapterAndAuthor}{0cm}{1.5cm}{1cm}  %%% Chapter style \titleformat{\chapter}[display]   {\normalfont}{\chaptertitlename\ \thechapter}{12pt}{\Large}  % Display chapters in the Table of Contents \titlecontents{chapter}   [0pt]% Left margin, optional   {}% Code insertet above   {\mdseries}% Numbered-entryformat   {\mdseries}% Numberless-format   {\contentspage\vskip1.5ex} % add dotfill and pagenumber, and some vertical space between entries  % Custom command to keep the author on the same page of chaptertitle, and above it. \newcommand{\chapterAndAuthor}[2]{%   % #1: Author   % #2: Chaptertitle   \clearpage   % Keep the author and chaptertitle on same page   \begingroup\let\cleardoublepage\relax\let\clearpage\relax   % Set the author style   {\fontsize{12}{14}\itshape \noindent #1}\par   % Bring the chaptertitle closer to the authortitle   \vspace{-0.21cm}   % Add an entry to the Table of Contents, with the name of    % the author in emph and the chapter title   \addcontentsline{toc}{chapter}{%     \texorpdfstring{%       \protect\parbox[b]{\dimexpr\textwidth-15.5pt}{         {\normalfont\itshape {#1}}%         \endgraf\vspace{0cm}         \leftskip=1em #2 \dotfill       }%     }{#2}%   }   % Print the chapter   \chapter*{#2}   \endgroup }  \pagestyle{plain}  \usepackage[pdftex]{graphicx} \usepackage[pdftex]{graphics} \usepackage{supertabular}  %SEITENLAYOUT%  \usepackage[paperheight=21.0cm,paperwidth=13.5cm,twoside,textwidth=10.3cm,textheight=16.3cm,nohead,pdftex]{geometry}  %SCHRIFTGRÃSSEN% \usepackage{fix-cm}  \makeatletter \g@addto@macro\normalsize{\fontsize{10.0pt}{12.0pt}\selectfont} %\fontsize{Fontgröße}{Grundlinienabstand} \g@addto@macro\footnotesize{\fontsize{9.0pt}{11.0pt}\selectfont} %\fontsize{Fontgröße}{Grundlinienabstand} \makeatother   \usepackage[hyphens]{url} \usepackage{multicol} \usepackage[colorlinks=false, pdfborder={0 0 0}, breaklinks = true]{hyperref} \urlstyle{same}  %%%%%%%%%%%%%%%%% end preambel %%%%%%%%%%%%%  \begin{document}  \tableofcontents \clearpage   \chapterAndAuthor{The name of the first author, The name of second author and The name of the third author}{Test Chapter One Test Chapter One Test Chapter One Test Chapter One Test Chapter One Test Chapter One Test Chapter One}  \noindent\lipsum[1]  \chapterAndAuthor{Johanna von Orleans, Charles de Secondat, Baron de MontesquieuMontesquieu, , Albert Einstein}{Test Chapter Two Test Chapter Two Test Chapter Two Test Chapter Two Test Chapter Two Test Chapter Two Test Chapter Two}  \noindent\lipsum[1]  \chapterAndAuthor{The name of the first author, The name of second author and The name of the third author}{Test Chapter Three Test Chapter Three Test Chapter Three Test Chapter Three Test Chapter Three Test Chapter Three Test Chapter Three}  \noindent\lipsum[1]    \end{document}

Is it possible to have in the toc no word separation but have a word separation in the chaptername:  For example:   Contents  1. max Mustermann   Chapter  Max Muster- mann


while using hindi content in jsp , inside either in div or  tag.it is showing some different symbols at the place of my text. how can I use the hindi content in my jsp file.

I need to get UTF-8 working in my Java webapp (servlets + JSP, no framework used) to support äöå etc. for regular Finnish text and Cyrillic alphabets like ЦжФ for special cases.  My setup is the following:   Development environment: Windows XP Production environment: Debian   Database used: MySQL 5.x  Users mainly use Firefox2 but also Opera 9.x, FF3, IE7 and Google Chrome are used to access the site.  How to achieve this?


The question in title has been considered for finite groups $G$ and $H$, but I do not know its situation, how far it is known whether $G$ and $H$ could be isomorphic. I have two simple questions regarding it.  Q.0 If $\mathbb{Z}[G]\cong \mathbb{Z}[H]$ then $|G|$ should be $|H|$; because, $G$ is a free basis for the free additive abelian group $\mathbb{Z}[G]$, am I right?  (I am asking this because in Isaac's character theory, I saw something different argument, not too lengthy, but I was thinking for the above natural arguments.)  Q.1 Are there known examples of finite groups $G\ncong H$ with $\mathbb{Z}[G]\cong \mathbb{Z}[H]$? (In the book of character theory by Isaacs, he stated for metablelian groups $G,H$, $\mathbb{Z}[G]\cong \mathbb{Z}[H]$ implies $G\cong H$; it was proved by Whitcomb, in $1970$; but book has not been further revised, I don't known what is done after $1970$).

The isomorphism problem for integral group rings asks if two finite groups $G,H$ are isomorphic when their integral group rings $\mathbb{Z}[G]$, $\mathbb{Z}[H]$ are isomorphic. Quite a lot has been done towards solving this and related problems. See for example Chapter 9 in Milies, Sehgal, "An Introduction to Group Rings". Now it seems that the first (?!) counterexample has been found by Martin Hertweck in his 2001 paper "A Counterexample to the Isomorphism Problem for Integral Group Rings". He has constructed two counterexamples, the one group has order $2^{25} \cdot 97^2$ and the other group has $2^{21} \cdot 97^{28}$. Do we really have to consider such huge groups? The thesis by Geoffrey Janssens discusses Hertweck's construction in detail, and claims that this is the only known counterexample. Is this still correct?  Question. What is known about the minimal counterexamples of the isomorphism problem for integral group rings?


To switch to Intel GPU from Nvidia 1050Ti, I entered "sudo prime-select intel". Something like: get Intel information showed up on the screen. I logged out and logged in. I went to About but it showed that Nvidia 1050 Ti was still being used. Next, I rebooted the machine. It showed a black screen with a blinking underline cursor on the top left. It stayed there foreover. I pressed the power button continuously. Then, the purple screen with Ubuntu in the middle showed up. After the few dots below Ubuntu turned on, the laptop shut down. I turned on the machine again. Blank purple screen showed up. Then a long list of sentences showed up on the screen quickly. So quick that I could not see what were written on it. Then, again the blinking cursor showed up on the top left. Could you please help to resolve the issue?

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


I have the following ffmpeg command which creates a multicast audio transmission to a IP address and port: ffmpeg -re -i Sample.mp3 -filter_complex "aresample=8000,asetnsamples=n=160,volume=0dB" -acodec pcm_mulaw -ac 1 -vn -f rtp rtp://229.1.2.3:500  However, I need to be able to run the multicast broadcast on a few different IP addresses. One way is to run multiple ffmpeg instances for each IP. But this seems a bit of a resource intensive way. Is there a way I can on the same single command have multiple multicast IP addresses and ports?

I'm really new on ffmpeg and have a question where I cannot find a solution. I really hope that somebody from you could help me with that.  On one server I receive a 1080p stream, with ffmpeg I create a new stream with multiple bitrates and resolution and send it afterwards to a rtmp destination on this server. Below CL the command that I use at the moment and it is working.  ffmpeg -i - -copyts -muxdelay 0  -c:a libfaac -ab 128k  -c:v libx264 -preset faster -profile:v main -level 3.1 -crf 20 -g 50 -b:v 1500k -s:v 1920x1080 -f flv rtmp://localhost/stream/output_stream  -c:a libfaac -ab 64k -c:v libx264 -preset faster -profile:v main -level 3.1 -crf 23 -g 50 -b:v 1000k -s:v 1280x720 -f flv rtmp://localhost/stream/output_stream  -c:a libfaac -ab 32k -c:v libx264 -preset faster -profile:v main -level 3.1 -crf 23 -g 50 -b:v 800k -s:v 960x540 -f flv rtmp://localhost/stream/output_stream   Now I have the challenge that I need to send it to multiple servers. Is there anyway to add multiple outputs?  At the end the incoming 1080p stream should get multiple bitrates and should be send to around 10 different RTMP server.  I really hope that somebody can help me with that.


I deleted Terraria so the local data would be deleted.   I tried re downloading the game but there was no old data that I played. Is it possible to get back? Will Copytrans Shellbee work?   My device is the iPad 4, running the iOS version of Terraria.

I was playing terraria today, and my friend came and deleted the my world.  Is there a way for me to recover my world?


Scientifically, can we say that one of these assertions is more "correct" than the other? (philosophically we can say that the first one is more correct because it makes the motion of other planets "simpler" to express)  Because of gravitation, the Earth is turning around the Sun.  Because of gravitation, the Sun is turning around the Earth.  (I want to keep the question open on all the specifities on the frames of reference (Galilean or not)).

In history we are taught that the Catholic Church was wrong, because the Sun does not move around the Earth, instead the Earth moves around the Sun.  But then in physics we learn that movement is relative, and it depends on the reference point that we choose.  Wouldn't the Sun (and the whole universe) move around the Earth if I place my reference point on Earth?  Was movement considered absolute in physics back then?


I need to generate something like this    for my water Shader, because on fly calculations are to expensive for mobile (). The texture needs to be seamless. I currently clueless where and how to make this happen (especially about the seamless thing). Any help appreciated!

Related:       I'd like to generate tileable Perlin noise.  I'm working from  PerlinNoise*() functions, which are like this:  // alpha is the "division factor" (how much to damp subsequent octaves with (usually 2)) // beta is the factor that multiplies your "jump" into the noise (usually 2) // n is the number of "octaves" to add in double PerlinNoise2D(double x,double y,double alpha,double beta,int n) {    int i;    double val,sum = 0;    double p[2],scale = 1;     p[0] = x;    p[1] = y;    for (i=0;i<n;i++) {       val = noise2(p);       sum += val / scale;       scale *= alpha;       p[0] *= beta;       p[1] *= beta;    }    return(sum); }   Using code like:  real val = PerlinNoise2D( x,y, 2, 2, 12 ) ; // test  return val*val*skyColor + 2*val*(1-val)*gray + (1-val)*(1-val)*cloudColor ;   Gives sky like    Which isn't tileable.  The pixel values are 0->256 (width and height), and pixel (0,0) uses (x,y)=(0,0) and pixel (256,256) uses (x,y)=(1,1)  How can I make it tileable?


I am watching some tutorials on how to navigate the filesystem but no matter which tutorial I watch there is one thing that no one seems to answer.  I understand that . is current directory. I understand that / is either root directory or it can just mean the end of a current directory.  So how come if I want to run a program in the current directory I have to do ./ProgramName? Is this just because ProgramName could be in $PATH and I have to specify that I want to run the version in the current directory? Why doesn't Ubuntu automatically run the current directory's version if there's no equivalent in $PATH?  And if so why am I allowed to omit ./ when I am traversing directories? For example I can just do cd DropBox from my home directory. I can also do cd ./DropBox and it seems to work but why isn't the ./ required?

While executing a C program, a.out, using the Ubuntu terminal, why do I always need to type ./ before a.out, instead of just writing a.out? Is there solution for this?


I have the following piece of code to get the valuetype. Is it possible to do this with getSObjectType() instead of getGlobalDescribe() since this is a lot slower. Apex Map<String, Object> fieldMap = (Map<String, Object>)JSON.deserializeUntyped(jSONSObject); Schema.SObjectType targetType = Schema.getGlobalDescribe().get(sObjectApiName); SObject newSobject = targetType.newSObject(); Map<String, Schema.sObjectField> targetFields = targetType.getDescribe().fields.getMap(); for (String key : fieldMap.keySet()) {     Object value = fieldMap.get(key);     Schema.DisplayType valueType = targetFields.get(key).getDescribe().getType();     if (value instanceof String && valueType != Schema.DisplayType.String)     {         String svalue = (String)value;         if (valueType == Schema.DisplayType.Date)             newSobject.put(key, Date.valueOf(svalue));         else if(valueType == Schema.DisplayType.DateTime)             newSobject.put(key, DateTime.valueOfGmt(svalue));         else if (valueType == Schema.DisplayType.Percent || valueType == Schema.DisplayType.Currency)             newSobject.put(key, svalue == '' ? null : Decimal.valueOf(svalue));         else if (valueType == Schema.DisplayType.Double)             newSobject.put(key, svalue == '' ? null : Double.valueOf(svalue));         else if (valueType == Schema.DisplayType.Integer)             newSobject.put(key, Integer.valueOf(svalue));         else if (valueType == Schema.DisplayType.Base64)             newSobject.put(key, Blob.valueOf(svalue));         else             newSobject.put(key, svalue);     }     else         newSobject.put(key, value); } insert newSobject;

I was about to reconfigure some of my code to use the newer Schema.describeSObjects(types) method that I had heard was faster than using a globalDescribe.   I made some code to quickly check this and I was dismayed to find that the newer technique is not only not faster, it's about twice as slow as using a global describe. Here's the code I used :  New DescribeSObjects() method  //each block was run separately for timing purposes String obj = 'Account'; String[] types = new String[]{obj}; System.debug('START DESCRIBE SOBJECTS');  for (Integer i = 0; i < 50; i++) {   List<Schema.DescribeSobjectResult> results = Schema.describeSObjects(types);  } System.debug('FINISH DESCRIBE SOBJECTS');   Old getGlobalDescribe() method  String obj1 = 'Account'; System.debug('START DESCRIBE GLOBAL');  for (Integer i = 0; i < 50; i++) {    Map<String,Schema.SObjectType> gd = Schema.getGlobalDescribe();    Schema.SObjectType sobjType = gd.get(obj1);    Schema.DescribeSObjectResult describeResult = sobjType.getDescribe();  } System.debug('FINISH DESCRIBE GLOBAL');   Over 5 runs of each, the getGlobalDescribe() method took an average of 337ms for 50 describes and the describeSObjects() method took and average of 658ms. This is basically twice as long.  Does anyone have any insight as to why this would be? Any improvements that will significantly improve the accuracy of the resulting data?  As this data stands, I'm sticking with the old method.  One final note: the old technique uses 3 times a much heap (67kb vs 27kb)


Reading p. 79 of the PHB, under the heading “Monastic Traditions”, it is somewhat unclear to me as to if it is possible for a monk to choose more than one tradition.  Part of my confusion comes from the fact that “a few (monasteries) honor the three traditions and instruct each monk according to his or her aptitude and interest”. The paragraph goes on to mention a “diverging” but not necessarily excluding the possibility of pursuing training in multiple traditions.

The way that 5e works, each class has a sub class that dictates a heap of class features. The question here is generally, can a character of a specific class take levels in that same class in order to gain access to the low level features of another sub-class.  The best example of this would either be the wizard or the cleric taking additional levels of wizard/cleric in order to gain access to another domain or school.  Like can a Life cleric take levels of Storm cleric or similar?  If this were allowed, what would the effects be on Maximum spell level and other class level based abilities?


I have been trying to download Ubuntu onto a new SSD drive, all seemed well until it asked me to restart, then I just got a blank screen on my monitor, so thinking something was wrong.I turned the PC off to restart again but I'm still not getting anything on screen but computer seems to be running in the background for about an hour now, do I need to start again from scratch or is that not possible?


having read the thread "He mustn't / couldn't have been hungry" , I am still unsure whether or not there is such a wording as "mustn't have past participle".   Situation: I saw Peter and Jane holding hands. Speculation (my choice): They must have been lovers. The opposite of this would be: They can't/couldn't have been lovers. Incorrect: They mustn't have been lovers.  What is the situation with "mustn't have past participle"? Is there such usage, and if yes, in what context?  Many thanks for explaining this once again.   Melinda

He will have painted the walls by tomorrow.      He must have painted the walls by yesterday.    Does each one have two different connotations?  So, if we have four different likelihood meanings, would you show me with an example?


Can I omit the comma before "and" since " through December 31, 2020" is applicable to both parts of the sentence? I'm afraid that if I put a comma here readers can think that only the second part is valid through December 31.  The books are available to you for free(,) and we do not charge commission fees through December 31, 2020.

Is using a comma then an "and" or an "or" after it proper punctuation? Example:         I fell over, and hurt my knee.   Should I go, or not?


I am trying to get the duration of a bunch of files in current directory and its sub-directories all ending in .mp4. I'm trying to use ffprobe. To make things simple, I am not using find, but ls. If it only lists durations in seconds, it will be fine, since summing them all up would probably be beyond me!   My current effort is like this:    ls -a * |grep .mp4$|xargs ffprobe   This shows      Argument 'SomeVideo.mp4' provided as input filename, but 'DifferentVideo.mp4' was already specified.   How can I make this work? Can ffprobe not just process one file at a time passed via pipe?

I have a list of .ts files:   out1.ts ... out749.ts   out8159.ts  out8818.ts   How can I get the total duration (running time) of all these files?


I know this is incorrect: John and me will be giving a birthday treat.  I know this is correct: John and I will be giving a birthday treat.  But what when the voice is changed? Birthday treat from John and I? Birthday treat from John and me?

I was told the correct usage is for example: "My wife and me" but I hear often "I and my wife" or "my wife and I". Google gives 34M results for "My wife and I" and 909K results for "My wife and me" Which is the correct form and why? It occurred to me that maybe it could depend on the rest of the phrase? (subject or object)  "My wife and I are eating an apple" "You can see my wife and me in this picture"


My husband has a six-months multiple-entry Schengen tourist visa. Can he go to attend an academic conference in the Netherlands for three days on the same visa? He has been to France on the same visa.

Lets say I have France Schengen visa (multiple entries short stay of total 90 days in 6 months). I understand that my first ever visit to Schengen zone has to be France as the main destination. My question is : If I happen to make subsequent visits to Schengen area (while my visa is still valid with regards to dates and total duration)  - is it required on every visit (second, third, etc.) that France be my main destination for the visit?  PS: I know that I can enter any Schengen country for my visit - but I am specifically asking if I can totally avoid visiting the issuing country on my subsequent visits? Will doing so be used against me if I apply for visa in future?


I know the one for the one variable version... β =∑ xiyi / ∑ x2  but nobody seems to have the one for the multiple variable version is there a way to do it by hand for something like  y = β1x1 + β2x2  (no intercept)  EDIT: this is about the MULTIPLE variable model equation (MUST go through the origin)..the answer provided is the one I tried that doesn't go through the origin

In An Introduction to Statistical Learning (James et al.), in section 3.7 exercise 5, it states that the formula for $\hat{\beta}_1$ assuming linear regression without an intercept is  $$\hat{\beta}_1 = \dfrac{\displaystyle\sum\limits_{i=1}^{n}x_iy_i}{\displaystyle \sum\limits_{i=1}^{n}x_i^2}\text{,}$$ where $\hat{\beta}_0 = \bar{y}-\hat{\beta}_1\bar{x}$ and $\hat{\beta}_1 = \dfrac{\displaystyle S_{xy}}{S_{xx}}$ are the usual estimates under OLS for simple linear regression ($S_{xy} = \displaystyle\sum\limits_{i=1}^{n}(x_i - \bar{x})(y_i - \bar{y})$).  This is not the actual exercise; I am merely wondering how to derive the equation. Without using matrix algebra, how do I derive it?   My attempt: with $\hat{\beta}_0 = 0$, we have $\hat{\beta}_1 = \dfrac{\bar{y}}{\bar{x}} = \dfrac{S_{xy}}{S_{xx}}$.  After some algebra, it can be shown that $\displaystyle S_{xy} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}\bar{y}$ and $\displaystyle S_{xx} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}^2$. From here, I'm stuck.


i want to increase the open file descriptor size in linux current size is   ulimit -n   returns 1024 i want to increase it to 65535 because my elasticsearch process needs it  here is the link i am following    i did added following line in /etc/security/limits.conf  *     soft   nofile  1024 *     hard   nofile  65535  root     soft   nofile  1024 root     hard   nofile  65535    rebooted the system and ulimit -n still returning 1024  another solution i added these lines in /etc/security/limits.conf   *    soft nofile 64000 *    hard nofile 64000 *        -  nproc   16384 root        -  nproc   16384 root soft nofile 64000 root hard nofile 64000   and  /etc/pam.d/common-session needs to have this line in it:  session required pam_limits.so   and added following line in /etc/pam.d/common-session-noninteractive :  session required pam_limits.so   rebooted the system and it did not worked either  followed this link as well   it gives error on the last command    ulimit -n unlimited bash: ulimit: open files: cannot modify limit: Operation not permitted   and    sudo ulimit -n unlimited sudo: ulimit: command not found   my elasticsearch process is giving me this error  [1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]   any help would be appreciated

I've run ulimit -n 65536, added the following lines to /etc/security/limits.conf:  *    soft nofile 65536 *    hard nofile 65536 alix soft nofile 65536 alix hard nofile 65536 root soft nofile 65536 root hard nofile 65536   And added session required pam_limits.so to both:   /etc/pam.d/common-session /etc/pam.d/common-session-noninteractive   And fs.file-max = 65536 to /etc/sysctl.d/60-file-max.conf.  Still, after restarting and running ulimit -n on my session, I only get 4096 (was 1024 before).  What am I missing?


We recently had some servers hacked (Ubuntu, various flavours) which installed a Monero miner that starts a process called watchbog. We scrubbed them clean and blocked access to where they can update themselves from but on reboot the servers start to rebuild the miners installation (and fails)  It is creating a directory /tmp/systemd-private-d3883bec41f94ab0b3d927e3022873b1-systemd-timesyncd.service-jVvrE0 and some subdirectories and then stops. The random bits are random each time  What I want to know is what is rebuilding this on boot. There does not seem to be anything obvious in the logs or the various boot scripts. Where else can I look?

This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.


I posted, possibly on softwareengineering.stackexchange.com, a question saying that a couple of recent bits of breakage on my Mac made me wonder if Apple was still being warm and fuzzy to the Unix community. (One was problematically frequent Terminal.app crashes; I don't remember the other one.) I believe the question was closed and possibly deleted as out of scope.  I would like to have what I wrote available for a blog post not intended to be under the Stack Exchange umbrella, but I'm having difficulty locating it; egosearches under apple.stackexchange.com and softwareengineering.stackexchange.com do not seem to show this post, and Google egosearches (site:stackexchange.com JonathanHayward Terminal.app) do not appear to show my post.  Am I correct in guessing that the post is not turning in searches because it was deemed off-topic? Is there any way any of the moderators here could fish it up?

I deleted one of my questions and would like to undelete it. This requires finding the question.  I think you shouldn't be prevented from seeing your own posts that you have deleted. It should be easier than me remembering the link or checking the browser history to easily look these up.   I would currently need 10K to see my deleted items and even then if I can find their URL.


I've had 3 Outlook 2016 users contact me today with the same problem. When they click any email, in there inbox, the preview pane is blank (as shown below):  Also, if they double-click any email (to open it in a new window) that email body is also blank. I've tried updating Microsoft Office 2016 and the problem persisted after being fully updated. Additionally, I tried deleting a user's email profile, and then re-syncing their email using Google App Sync (because the server is not exchange; it is Gmail). Even after a fresh re-sync the problem persists. Of course, if these users check their Gmail, the email bodies show just fine. Have any of you experienced this issue, and if so, how did you get past it?

I'm experiencing a strange problem with Outlook 2019. When viewing a message it only shows the first line. On an HTML message, it stops at the first close paragraph tag. On a plaintext message, it stops at the first newline character. This is true if viewing a message in the reading pane as well as if double-clicking the message to open in its own window. I have the preview pane set to show 3 lines and it does show more of the message so it seems like Outlook can see more of the message than it's rendering in the reading pane. If I use View Source, the underlying data seems fine and the whole message is there. I've tried the following:  Deleting and re-creating the user's mail profile Uninstalling & re-installing Office Creating a new Windows account & connecting Outlook to a different Exchange account than the one that originally exhibited the problem Checked for Windows updates Checked for Office updates  Any ideas what might be causing this? I feel like I've tried everything obvious & I'm striking out on Google.


I regularly travel from Canada to the US by bus and get a US Visa Waiver attached to my passport, which I hand back to the Canadian customs officer when returning to Canada (by bus).  This time I entered the US by bus as usual, but left the country by airplane. When I tried to surrender the visa waiver to the Canadian customs officer upon arrival at the airport in Canada, he informed me he had never seen this before, and did not take the waiver out.   I understand that usually when flying to/from the US these records are handled through ESTA. Does that mean there is a valid record of me leaving the US, and that I can take out the waiver myself? Are there any additional steps I should be taking?

Three years ago I was on holidays in Canada and visited the Niagara Falls. I also went to the American side of the falls and got something like a "short-term visa". I also got a green paper with all my information (name, passport number, etc.) which I should give back at the border when leaving USA again.  When I got back from the USA side of the falls, the border was abandoned. Therefore I couldn't give the green paper back to the officials. Now I'm really a bit afraid that in their computer system I still haven't left the USA.  Next summer I plan to visit USA again. Can I get into trouble at the border?


Where can I download the Chrome i386 deb file? Google does not allow installing Chrome 32 bit from its web anymore. I am running xubuntu 15.10

I am using Google Chrome 48.0 32-bit. Today when I launched Google Chrome, I got this message:    This computer will soon stop receiving Google Chrome updates because this Linux system will no longer be supported   I thought Ubuntu 14.04 is supported for five years, what's exactly happening here?  And on 64-bit Ubuntu, I get an error from Update Manager and apt-get update:  Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)   Some index files failed to download.   They have been ignored, or old ones used instead.


Just need to know how to give the rectangle this shade kind of effect at the very ending and I also need to know how to cut the bottom line. I need info on exactly how to replicate this amazing rectangle designed by the TypeForm website.  I am not replicating them for a project but for my educational purpose.  Thanks in Advance

Looking to try and fade out an image in illustrator using the blend tool.  At first, I tried blending 2 clipping groups, but I knew that wasn't going to work.  Then I tried blending just the linked image, but that wasn't working either.  Is there anyway to blend a clipping mask so that an image can fade out on the edges?


Past participles in the English language usually end with -ed, but slain is one exception. Why can't we have just slayed rather than that and slain, too? And why can't slain be its very own verb?

This is a question people seldom ask. In the English language, past participles are verbs that usually end with -ed. But bear seems to be an exception. It has bore and borne as past participles, but not beared. Why do they even exist? That doesn't make any sense. Update: I'm not familiar with the term Germanic language or inflectional morphology.


If every Jordan curve $J \subset D$ is null-homotopic in a domain $D \subset \mathbb{R}^2$, then is it clear that every closed curve $C \subset D$ is also null-homotopic in $D$?  Apparently the set $\mathbb{R}^2 \setminus C$ is an union of countably many Jordan domains $D_i$, but it's not clear to me that the result for every $\partial D_i$ is enough. What is the right approach?  EDIT: Before you mofos shut down my question with silly down votes I ask to check out the following link   There this question is answered with seemingly simple compactness argument. It would be nice if someone of you can explain why those argument are enough?

Problem. Assume that $U$ is an open and connected subset of $\mathbb R^2$, and $\gamma :[0,1]\to U$ is a closed curve, which is not null-homotopic in $U$ and not necessarily simple closed. Show that there exists a simple closed curve, which is not null-homotopic in $U$.  I am sure that this is a standard problem, and I am looking for an elegant, if possible, solution or a reference. I have in mind the following sketch of proof:  a. Construct a polygonal closed curve $\tilde\gamma$ which is homotopic with $\gamma$ in $U$.  b. Construct $\tilde\gamma$ so that it intersects itself in finitely many points, and not whole segments.  c. Use induction on the number of self–intersections of $\tilde\gamma$, in order to show that $\tilde\gamma$ is written as a product (in the fundamental group's sense) of simple closed polygonal curves.


Are there fields that are not algebraically closed fields but such that any quadratic polynomial has a root?  Suppose now $n$ is a fixed natural number, $n\geq 2$. Is there a field $K_n$ such that every polinomial of degree $\leq n$ with coefficients in $K_n$ has a root in $K_n$, but $K_n$ is not algebraically closed?     I was thinking that perhaps a tower of algebraic extensions of $\mathbb{Q}$ might work, but then I realized that in order to be "quadratically closed" I might have to close under all extensions of degree $2^k$ for some $k$.   Is $K_2=\bigcup \left\{\mathbb{Q}[\alpha]: [\mathbb{Q}(\alpha):\mathbb{Q}]=2^k\text{  for some $k$}\right\}$ going to work as a field that is quadratically closed but not algebraically closed?

My problem is to build, for every prime $p$, a field of characteristic $p$ in which every polynomial of degree $\leq n$ ($n$ a fixed natural number) has a root, but such that the field is not algebraically closed.  If I'm not wrong (please correct me if I am) such a field cannot be finite, by counting arguments. But on the other hand, the union of all finite fields (or of any ascending chain of finite fields) of characteristic $p$, which is what I get if I start with $F_p$ and add a root to each polynomial of degree $\leq n$ in each step, is the algebraic closure of $F_p$, hence algebraically closed. I don't see how I can control this process so that in the end I get a field that is not algebraically closed.  Any hint will be welcome. Thanks in advance.


The image link describing the bug / ill-feature is here:    My PC and Windows are working fine, however for the past few days I'm getting an annoying window drag over any window.  My OS is: Windows 8.1 Pro  Whenever I drag any open window, only the borderline with a black color is seen as dragged and not the whole window.  I tried refreshing the PC but it encounters some problem, and I don't have a system restore point right now in my system.  Please suggest how to remove this annoying window drag feature.

How do you turn on and off window repaint while drag moving/re-sizing window in Windows 7?  When I drag a window or resize it, I just get a wireframe.  Some how this feature has gotten turned off.  thanks


I wrote this method to check if the code valid or not: private boolean validateDeleteBacklog(String code) {         if(code != null && !code.equals("")) {             if(code.length() == 6) {                 Pattern specialCaracter = Pattern.compile("[$&+,:;=?@#|'<>.-^*()%!]");                 boolean specialCar = specialCaracter.matcher(code).matches();                 return specialCar;              }         }         return false; }  when i use code = "abc123" it return always false inside of true. Where is the problem here?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Meta Stack Overflow has gotten a bit (well, not just a bit) out of hand, what with all of the ponies, the perfect freehand circle obsessions, the parakeets, the haikus, the ponies, the circle and the haikus, and that's only half of the problem.  I'm not suggesting anything at all similar to , since I seriously want to be able to talk about how weird Meta Stack Overflow really is.   My only hope is that MMSO will not get as screwy as MSO is right now, since then we'd be on our way to an infinite (or rather, 411 time) recursion, unless we can define a base case of some sort.  Any ideas? And please no ponies.

Meta Stack Exchange (which  after the Stack Exchange network was spawned) is great; it gives you a chance to talk about the Stack Exchange network in a disconnected forum so that you don't have to break the fight club rules of , and can do so generically.  But what about the cases when you want to talk about Meta Stack Exchange?  I would assume that the same rules apply in that you cannot talk about Meta on Meta.  So where is a guy to go?


I have known this from beginning that $1729$ is the smallest number expressible as the sum of two cubes in two different ways:   $$ 12^3 + 1^3 $$  and   $$ 10^3+9^3 $$  I am a Software Developer and if someone can tell me the logic to write a program for printing such types of number will be greatly helpful.

This is a final exam question in my algorithms class:  $k$ is a taxicab number if $k = a^3+b^3=c^3+d^3$, and $a,b,c,d$ are distinct positive integers. Find all taxicab numbers $k$ such that $a,b,c,d < n$ in $O(n)$ time.  I don't know if the problem had a typo or not, because $O(n^3)$ seems more reasonable. The best I can come up with is $O(n^2 \log n)$, and that's the best anyone I know can come up with.   The $O(n^2 \log n)$ algorithm:    Try all possible $a^3+b^3=k$ pairs, for each $k$, store $(k,1)$ into a binary tree(indexed by $k$) if $(k,i)$ doesn't exist, if $(k,i)$ exists, replace $(k,i)$ with $(k,i+1)$ Transverse the binary tree, output all $(k,i)$ where $i\geq 2$   Are there any faster methods? This should be the best possible method without using any number theoretical result because the program might output $O(n^2)$ taxicab numbers.   Is $O(n)$ even possible? One have to prove there are only $O(n)$ taxicab numbers lesser than $2n^3$ in order to prove there exist a $O(n)$ algorithm.  Edit: The professor admit it was a typo, it should have been $O(n^3)$. I'm happy he made the typo, since the answer Tomer Vromen suggested is amazing.


After submitting a paper to a journal, the paper will be sent to a reviewer by editor in such a way the name of authors will be hidden for referee.  In some cases in the list of references, sometimes there exists papers belong to authors which cite them by authors in the paper. In other words, it is not difficult to extract the name of authors from the reference list, isn't it? How can this issue be managed (in the case of importance of not-knowing the name of authors for referee)?

I've read a lot of answers here about double-blind reviews and thesis or single articles.  My problem comes from having four self-references in my article. I feel that if I include them all, could be very easy to infer that this is the fifth one (It's a 4-year granted project and I have been collaborating in a number of software components inside a bigger architecture, now it's the time to use them all to interact with other applications) . But if I ommit some of them, I could end being accused of self-plagiarism. The other articles have been published in the proceedings of conferences that didn't require double-blind reviews, this is the first submission I make to a conference that asks for it (Maybe because of being CORE A) Also not worthless to mention that I'm going to send it as a short paper, so actually it'd be very helpful to cite rather than to repeat past texts.  What should I do?


I have an AVI file rendered from an animation. I would like to play it on a "TV" in a different animation. I have added it as an image texture on the "TV" and if I step through the frames I see the animation. But when I run the animation (Alt+A) there is no animation on the "TV", only the first frame. If I stop the run (Alt+A again) the "TV" shows the correct AVI frame.  I haven't tried a full-up render of the new animation because each frame takes about 8 min. The question: how can I get the AVI "movie" to play on the "TV" in my "living room" scene?

I am trying to animate in 2d. I do it with planes that have textures on them. I recently came up with the idea of having a plane with an image sequence of mouths because animating actual lip syncing by hand takes too long and isn't really necessary for what I'm trying to acomplish. However, when playing back the animation in textured viewport shading the animated texture stays at the last frame until the animation stops. I can use the arrow keys and it works fine as well as scrubbing through the timeline, just not when playing back the animation with alt+a. Can anyone help me with this problem?


I remember a long time ago I was in some charity event my parents basically dragged me to, and I remember a girl there who said she's Canadian/from Canada and so it got me wondering:  1.If she's Canadian she's born in Canada and is probably not a U.S. citizen.  2.If she was in a charity event and wasn't a U.S. citizen, does that mean anyone can volunteer?  I ask because I think you need a work permit if you do any kind of paid work abroad when you're not a citizen, but volunteer/charity work isn't paid and the situation is obviously different.  Can non-citizens and/or only temporary visitors/residents do charity/volunteer work in the US?

I am going to Santa Monica for 4 weeks to polish my English in July and would like to volunteer at the Planetary Society located in Pasadena.  I am a Swiss citizen and have a biometric passport. However, I don't have any special visa, as there is no visa needed for the school I am attending and using the Visa Waiver Program, I am allowed to stay up to 90 days in the US.  Am I allowed to do volunteer work during my stay?


Now, when Windows 7 support has discontinued, if I install brand new Windows 7 on my machine (my laptop has possibility to make a factory reset), will it still get all updates automatically from the point it was launched up to 2020 Jan. 14? Do the same rules apply for Windows 8? Is there a way to download and install all of these updates manually if automatic update fails?

Today is the End of Life for Windows 7. Of course MS will not release new updates or patches for Windows 7 anymore.  If I install a new PC by a Windows 7 disc from scratch, I would expect I will not be able to download the Windows Updates. When I open "Windows Update" and check for updates, I would expect nothing will be found. (Correct?)  However in the MS website, there is a . It seems that we can download all the updates from there. As we all know Windows XP was EOL years ago. We can still find Windows XP updates from there.  Let me assume that the Microsoft Update Catalog contains ALL the updates and patches for Windows 7 now. (Correct?)  And let me assume that the Windows 7 updates and patches will still be available (for a few years) in the Microsoft Update Catalog even after Windows 7 EOL. (Correct?)  As MS is actually still hosting the update files in their server (the Microsoft Update Catalog), why MS does not keep steaming those OLD updates and patches to users through the OS built in "Windows Update" service?


This particular question was part of my analysis assignment I was unable to prove / disprove it.  Let $V$ denote the vector space of all sequences $a=(a_1 , a_2,...,a_n,...)$ of real numbers such that $\sum_{n\geq 1} 2^n |a_n|$ converges. Define ||.||: $V \to \mathbb{R}$ by $||a|| =\sum_{n\geq 1}2^n |a_n|$. Then is $V$ complete normed space or not.  There were four questions to be answered regarding $V$ . I have done 3 but unable to do this. I know about completely normed space but I was unable to do this . The  idea is to show that every sequence of sequence converges to a limit and that limit is to be constructed or guessed but I am unable to do it Kindly guide on how this should be done

Define  $\|\cdot\|\colon V  \rightarrow \mathbb{R} $ by $\|a\| = \sum 2^n |a_n|  $,  where  $V$ denotes the vector space  of all sequences  $a=(a_1,a_2,a_3,\dotsc)$ of real numbers such that $\sum 2^n |a_n|  $ converges.  Which of the following are true?  1) $V$ contains only the sequence $(0,0,\dotsc)$  2) $V$ is finite dimensional  3) $V$ has a countable linear basis  4) $V$ is a complete normed space  My answer:  it is already given that $\sum 2^n |a_n|  $ converges. That  means $V$ contain contains  only the sequence $(0,0,\dotsc)$ so option 1) is correct.  Option 2  is  incorrect because  $\mathbb{R}$ is  uncountable, as continuous image of uncountable  is  uncountable.  I'm confused  about option 3 and option 4.  Please help me.  Any hints/solution will be  appreciated.


How do I construct a triangle when I am given 2 sides and the radius of the inscribed circle. Keep in mind the problem must be solved in euclidean geometry so we assume that we don't know trigonometry other fields of "advanced" geometry.

A Triangle has 2 sides of length 4 and 9. The largest circle than can be drawn in the triangle so as to touch all 3 sides has radius 1 cm. Find the length of the 3rd side.


So I want a gvim or sed command which would insert a string (new_string) before the first match (//). For instance   Say the input is            --> hi hola //Comment Then the output expected is --> hi hola new_string //Comment   So basically I want to add a string just before the first occurence of //. I tried the sed command   sed 's/\<\/\/\>/Really &/' file   However, this doesn't work for // substring.

I would like to update a large number of C++ source files with an extra include directive before any existing #includes. For this sort of task, I normally use a small bash script with sed to re-write the file.   How do I get sed to replace just the first occurrence of a string in a file rather than replacing every occurrence?  If I use  sed s/#include/#include "newfile.h"\n#include/   it replaces all #includes.   Alternative suggestions to achieve the same thing are also welcome.


Calculate the real solutions $x\in\mathbb{R}$ to      $$ \sqrt{5-x} = 5-x^2 $$   My Attempt:  We know that $5-x\geq 0$ and thus $x\leq 5$ and  $$ \begin{align} 5-x^2&\geq 0\\ x^2-\left(\sqrt{5}\right)^2&\leq 0 \end{align} $$  which implies that $-\sqrt{5}\leq x \leq \sqrt{5}$. Now let $y=\sqrt{5-x}$. Then  $$ \tag1 y^2=5-x $$  and the equation converts into  $$ \begin{align} y &= 5-x^2\\ x^2 &= 5-y\\ y^2-x^2 &= 5-x-(5-y)\\ y^2-x^2 &= y-x\\ (y-x)(y+x)-(y-x) &= 0\\ (y-x)(y+x-1) &= 0 \end{align} $$  So either $y=x$ or $x+y=1$.  Case 1 ($y=x$):  We can plug this into $(1)$ to get  $$ \begin{align} y^2 &= 5-x\\ x^2 &= 5-x\\ x^2+x-5 &= 0\\ x &= \frac{-1\pm \sqrt{1+20}}{2} \end{align} $$  Since $-\sqrt{5}\leq x\leq \sqrt{5}$, the only solution is  $$ x = \frac{-1+\sqrt{21}}{2} $$  Case 2 ($y=1-x$):  We can plug this into $(1)$ to get  $$ \begin{align} y^2 &= 5-x\\ (1-x)^2 &= 5-x\\ 1+x^2-2x &= 5-x\\ x^2-x-4 &= 0\\ x &= \frac{1\pm\sqrt{17}}{2} \end{align} $$  Since $-\sqrt{5}\leq x\leq \sqrt{5}$, the only solution is  $$ x = \frac{1-\sqrt{17}}{2} $$  So final solution is  $$ x \in \left\{\displaystyle  \frac{1-\sqrt{17}}{2}, \frac{-1+\sqrt{21}}{2} \right\} $$  Is it possible to solve this problem using geometry? For example, could we use the properties of a half-circle and a parabola?


It can become quite tedious to put multiple variations of spelling into and if statement and I was wondering if there is a way I could make the if statements case insensitive so I only need to put in one thing. I'm just picking up python again and couldn't find a good way online.

How can I do case insensitive string comparison in Python?  I would like to encapsulate comparison of a regular strings to a repository string using in a very simple and Pythonic way. I also would like to have ability to look up values in a dict hashed by strings using regular python strings.


Given an SVG drawing of a building, and 2 GPS-reference points, as well as where north is in the drawing, how can I import a building into QGIS so the 2 GPS-reference-points are at the same coordinates  ?

I want to  create a small web application to visualize election results on a per poll site basis for my city. The result is going to be very similar to what has been done for Berlin . Hopefully this helps in understanding what I'm going for.  The election raw data on the scale I need is published and I know how to visualize this on the grounds of a shapefile with separate polygons lining out the election districts. My problem is - as you could probably guess - that something like this doesn't already exist.  What actually is published though, is a PDF file lining out the borders of the districts I'm interested in:   I'm not keen on redrawing the linework myself, so I'm looking for a way to make a shapefile out of this. Luckily, the PDf includes the linework as separate vector objects, I extracted these into a SVG file:   I already tried converting the SVG to a DXF and importing it into qgis 2.0.1. This actually works, but (as expected) places the vectors in the atlantic ocean and I can't find a way to edit it and fix this.  What can I do now to georeference these vectors with open source tools and finally produce a shapefile?


I saved a map, and when I went to open it back up, I was prompted with a dialogue box saying Handle Bad layers.  What does this mean? The map was fine when I saved it.

I'm new to QGIS and have been seeing what it can do for me – seems good. I imported shape file data from a UK Ordnance Survey data file and saved the file in a new folder. It was very good, doing all I wanted. I exported and got exactly what I wanted ( a tiff image).   I closed the file in order to try a new experiment. When I went to re-open it I got a dialogue box saying 'Handle Bad Layers. I don't understand what is at issue and what to do.


In the late '90's I read a book where the main character would constantly reincarnate and have a life 'do over' until an inevitable heart attack that would always occur at the same date and time. Each life would start a little later (he would re-inhabit his body at a slightly later stage). He meets a woman who is having the same experiences as him, and they have a relationship that spans lifetimes. Each new iteration of their lives they look for each other, sometimes having to wait until the other person reincarnates before continuing on their research into their condition again.

This novel is about a character who jumps back in time to relive his life.  It's called “replayer” or something like that but Google didn’t help with the variations I tried.  He’s in his office talking on his phone to his wife, and she is saying “We have to…” and he feels like he has a heart attack, and wakes up in a “very messy room” which he quickly discovers is his young self.  Each time his life ends at the exact same date and time, but each jump is not as far back.  He meets another replayer and they have a love spanning many lifetimes. He (as a rich hermit) first notices her because of a movie she made.  to try and find others, they posted a newpaper ad with the “remember when” theme, listing slogans from the future.  A few replied with wrong ideas about what the ad was concerning.  One replied with proof of his own, adding Tylonol Scare and Princess Di to the list.  They knew which stocks to but for long-term investment, simply from remembering brand names in the future.  Investment consultants were the cover they used when visiting the other guy they had found (who was in an institution for the criminally insane, BTW).  What novel is this?


US Citizen here. After my first stay of 90 consecutive days in the Schengen zone, how long do I have to stay outside the zone before I can come back for another 90 day consecutive stay? The 90/180 rule has me confused when I try to figure out when I can come back for another 90 day stay.

I have searched the web a lot and could not find an answer that fits my situation. Here are two links that are quite contradictory:       My situation:  I've visited Portugal in December 2012 for 29 days on a Schengen visa valid from December 1st, 2012 to February 1st, 2013 for research purposes (I am a Ph.D. student). I want to visit Sweden from February 10th, 2013 to May 10th, 2013 (89 days). I have applied for a Schengen visa again (for research). How will the 90/180 rule work in my situation?


I have created a new plugin in QGIS3 with PyQt5 using Plugins Builder and when i want to add my code in module.py gives an error  the code used is       layers = self.iface.legendInterface().layers()     layer_list = []     for layer in layers:             layer_list.append(layer.name())      self.dlg.comboBox.addItems(layer_list)   the error message is      AttributeError: 'QgisInterface' object has no attribute   'legendInterface'  Traceback (most recent call last):   File   "C:/Users/REDADRISSI/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\reda\module.py",   line 187, in run       layers = self.iface.legendInterface().layers() AttributeError: 'QgisInterface' object has no attribute 'legendInterface'

The following piece of code works well in QGIS 2.x, however it does not work in QGIS 3.x.  myDir = 'd:/work/output_folder/' layers = iface.legendInterface().layers() pipe = QgsRasterPipe() for layer in layers:  extent = layer.extent()  width, height = layer.width(), layer.height()  renderer = layer.renderer()  provider=layer.dataProvider()  crs = layer.crs().toWkt()   pipe.set(provider.clone())  pipe.set(renderer.clone())  opts = ["COMPRESS=LZW"]   file_writer = QgsRasterFileWriter(myDir + layer.name() + ".tif")  file_writer.setCreateOptions(opts)  file_writer.writeRaster(pipe,       width,          height,          extent,          layer.crs())   This is the error I get when I run the code:  Traceback (most recent call last):   File "C:\PROGRA~1\QGIS3~1.0\apps\Python36\lib\code.py", line 91, in runcode     exec(code, self.locals)   File "<input>", line 1, in <module> AttributeError: 'QgisInterface' object has no attribute 'legendInterface'   Does someone know what has replaced 'legendInterface' in the new version or what other changes I might have to make to get this to run in QGIS 3.0?


given problem is,  If $\Sigma\vdash\varphi$ iff $\Sigma\vdash\psi$, then $\Sigma\vdash\varphi\leftrightarrow\psi$.  I can prove this using sound&completeness theorem but I don't know how to do without those theorems.  without them, I proved when $\Sigma\vdash\varphi$ is true, but I couldn't prove when $\Sigma\nvdash\varphi$. without the theorems, I don't know how $\nvdash$  part contributes to prove the problem.  p.s. only member of given set, tautology, and Modus Ponens are allowed for deduction.

Problem is showing or disproving in Sentential logic that:  If $\Sigma$$\vdash$$\varphi$ iff $\Sigma$$\vdash$$\psi$, then  $\Sigma$$\vdash$$\varphi\leftrightarrow\psi$  But I wonder how to show that there exists(or there's no) such a deduction.   To show opposite direction, I write as follows:  Suppose that $\Sigma\vdash\varphi\leftrightarrow\psi$  , i.e. there exists a deduction $<a_{1},a_{2},\cdots,a_{n}>$  such that $a_{n}=\varphi\leftrightarrow\psi$  . Then assume $\Sigma\vdash\varphi$  , i.e. there exists a deduction $<b_{1},b_{2},\cdots,b_{m}>$   such that $b_{m}=\varphi$  . Then a sequence $ <a_{1},\cdots,a_{n},b_{1},\cdots,b_{m},\psi>$   is a deduction from $\Sigma$   to $\psi$  . Thus, $\Sigma\vdash\psi$  . Then assume that $\Sigma\vdash\psi$  , i.e. there exists a sequence $<c_{1},c_{2},\cdots,c_{l}>$   such that $c_{l}=\psi$  . Then a sequence $<a_{1},\cdots,a_{n},c_{1},\cdots,c_{l},\varphi>$   is a deduction from $\Sigma$   to $\varphi$  . Thus, $\Sigma\vdash\varphi$  . Thus, If $\Sigma\vdash\varphi\leftrightarrow\psi$  , then $\Sigma\vdash\varphi$   iff $\Sigma\vdash\psi$  .  It seem to me that it is similar to this one. But I don't know how to do it.  This is my new answer:  Comsider $\Sigma=\{p,q\}$  . Then $\Sigma\vdash\varphi$   and $\Sigma\vdash\psi$  . Thus, $\Sigma\vdash\varphi$   iff $\Sigma\vdash\psi$  . But for a truth assignment $\nu$   of $\Sigma$   such that $\bar{\nu}(\varphi)=T$   and $\bar{\nu}(\psi)=F$  , $\bar{\nu}(\varphi\leftrightarrow\psi)=F$  . Thus, $\Sigma\nvDash\varphi\leftrightarrow\psi$  . It means that, by completeness of Sentential Logic, $\Sigma\nvdash\varphi\leftrightarrow\psi$  .   Deduction from $\Sigma$  is a finite sequence of sentences which consists of  members of $\Sigma$ , tautology, or sentences obtained by Modus Ponens  And biconditional is not a part of this language.


Good morning, i have a big problem with this proof. I haven't idea about this proof.   Problem:   Suppose $\lim_{n\rightarrow\infty}a_n =L  $ then $\lim_{n\rightarrow\infty}\ \frac{a_1+a_2+\cdots+a_n}n=L  $  I've tried this:  $| a_n-L|<\varepsilon\Rightarrow L-\varepsilon<a_n<L+\varepsilon$ Please help!!

I haven't been able to solve this by using the definition of limit. I think maybe trying induction will work, though. Can someone help?  Suppose $\lim \limits_{n \to ∞} a_n=L$. Prove that $\lim\limits_{n \to ∞} \dfrac{a_1+a_2+\cdots+a_n}{n}=L$


If white coloured light falls on an object, colours of certain wavelengths is absorbed and colour of certain wavelength is reflected. We see the object's colour as the reflected colour.   Then what happens to the absorbed light? Does it move electrons to upper orbit? Then the object should emit some light when they come to their natural state which doesn't happen because then we would also see the absorbed colour. So what really happens to the absorbed colour?

If I am not wrong when light hits for example white wall most of the photons are absorbed and transformed into heat and few of the photons at certain wavelength are reflected from the object. So white wall reflects photons at wavelength corresponding to white color so we can see it.  1.Can someone clarify if it is correct?  2.What happens if that photons reflected from white wall hit another white wall (are they reflected once? If that so can they be reflected forever?)  3.What happens when I "shoot" photons of certain wavelength into object which color corresponds to that photons wavelength e.g. Blue light into blue wall


Given prime $p>2$, prove that $2(p-3)! \equiv -1 \pmod{p}$.  I know that I have to use Wilson's theorem but I have no idea how to do so. Wilson's Theorem : For prime $p$, $(p-1)! \equiv -1 \pmod{p}$. Any help is appreciated.

Suppose that $p$ is a prime. Suppose further that $h$ and $k$ are non-negative integers such that $h + k = p − 1$.   I want to prove that $h!k! + (−1)^h \equiv 0 \pmod{p}$  My first thought is that by Wilson's theorem, $(p-1)! \equiv -1 \pmod{p}$, and $h!k!$ divides $(p-1)!$ (definition of a binomial). Where would I go from here?


I am having some problems with a sorting problem.  The statement:  Write a method KthLargest() that, given an array containing integers in some arbitrary order and an integer k, returns the k-th largest element in the array. Assuming that k is a small number and n is a very large number, your algorithm should be as fast as possible in terms of the worst-case number of comparisons, so do not sort the entire array of size n to find out the k-th largest element. You may use the Arrays.sort() method provided in the Java library.  I have clear ideas on how to do this problem... That is if I can sort the entire array first.  public static int KthLargest(int[] inputArray, int k) {     Arrays.sort(inputArray);     return inputArray[k]; }   However, the problem statement specifically states that I must not sort the entire array.

I believe there's a way to find the kth largest element in an unsorted array of length n in O(n).  Or perhaps it's "expected" O(n) or something.  How can we do this?


ok heres where im confused at so ho did zamasu come back if burees kill him and dont yall remember after grand master zeno destroyed the comos and goku and everybody came back and when came back burees said ill go kill your zamasu aka trunks zamasu before he go crazy or whatever and truks went back home so how did he com back

In the recent story of Dragon Ball Super, the present Zamasu has been killed by Lord Beerus but is still alive in the future. It has been told that Goku Black is Zamasu in Goku's Body, while Zamasu is the one from the past. All these things seem messed up. Can anyone provide a simple explanation of how all this timeline stuff works?


We're making an app in Unity. We're building it for Android and iOS. We also have a server. In order to use our server you need to present our api key for the server. So, we need to store that key in the build somewhere (eg. APK file) But how can we put it anywhere where people wont be able to get it? Eg. they can get the APK and decompile it. SDKS for unity for facebook and so on, store an api key in the client. What do they do?

GameJolt is a gaming platform/website that offers API access with features like achievements tracking for users, etc. I can use the API no problem on my tests but what I'm concerned about is the private key that is issued to my game. How do I ensure that it's protected from people that want to decompile my game? Once  they get the API private key, they will be able to do anything with it.


I have the following function block that complete fine when the client is accessing the server somewhere close like within the US. However, when the client is farther away, like Eastern Europe, the download of large files fails. Any ideas on how I can simulate traffic from a distant IP address? Or any other ideas to make this download and occur faster.  The files are moderatley large, i.e. 100 MB. They are on the same server as the web site is served from. I'm using C# .NET Framework 4.5 IIS 8  System.IO.Stream stream = null; int bytesToRead = 262144; byte[] buffer = new Byte[bytesToRead];  try {     var response = HttpContext.Current.Response;     response.ClearContent();     response.Clear();      //get file from file system     string path = Properties.Settings.Default.DownloadDirectory + fileId;     var fileInfo = new FileInfo(path);     if (fileInfo.Exists)     {         using (stream = new FileStream(path, FileMode.Open))         {             response.ContentType = mimeType;              response.AddHeader("Content-Disposition", "attachment; filename=\"" + name + "\"");             response.AddHeader("Content-Length", fileInfo.Length.ToString());              int length;             do             {                 if (response.IsClientConnected)                 {                     length = stream.Read(buffer, 0, bytesToRead);                     response.OutputStream.Write(buffer, 0, length);                     response.Flush();                     buffer = new Byte[bytesToRead];                 }                 else                 {                     length = -1;                 }             } while (length > 0);              stream.Close();             response.End();         }     } }

I need to simulate a low bandwidth, high latency connection to a server in order to emulate the conditions of a VPN at a remote site. The bandwidth and latency should be tweakable so I can discover the best combination in order to run our software package.


I'm looking for an example for path connected subspace of   $\Bbb{R}^2$ (euclidean topology) that is not locally path connected at any point. Will appreciate any help

I am trying to construct a topological space that is path connected, but nowhere locally connected.  If we define $p = (0,1)\in\mathbb{R}^2$, and for all $q\in\mathbb{Q}\cap[0,1]$ $T_q = \{v\in\mathbb{R}^2\ |\ \exists t\in[0,1],\ v = (1-t)p + t(q,0)\}$, then  $$ T = \bigcup\limits_{q\in\mathbb{Q}\cap[0,1]}T_q $$ the space of all lines connecting rationals in $[0,1]\times\{0\}$ to $p$, can be shown to be path connected but locally connected only at $p$. I thought of attempts to maybe generalize the idea to make the desired result. The immediate one of these attempts was to maybe 'rational duplicate' $p$ along the $y = 1$ line, i.e. to let $T$ be all the lines connecting every rational point on $[0,1]\times\{0\}$ to every rational point on $[0,1]\times\{1\}$, but the proof attempt did not go (I am not sure if this is correct).  Another idea was maybe a space-filling curve, but this seems a bit exotic.


So if you look a the image I extruded the side and filled a face at top, the bottom is empty and I wanted to create a loop around the 3 sides but it will only appear for one side any tips.

why does the loop-cut-and-slide operation ignore certain faces but happily cut others?the model is symmetrical so it is a bit strange to pick 3 faces that won't get cut. I tried applying it to see if it was just a graphics glitch causing the purple line to not display over everything, but it did end up cutting only what the line was selecting, instead of the whole mesh.    as requested,here's a paste of the blend:


Comic story about a group of explorers/tourists on another planet who are engulfed by a large semi-sentient life form (eg a slime mold?). They are able to communicate, quarrel etc. but cannot escape (at least for a while). Read this at least 40 years ago, any help appreciated...

I think this story dates from the 1950s, plus or minus a decade - I read it about 30-35 years ago in a (then) fairly old story collection. It involves explorers on a planet falling into a gelatinous object that dissolves most of their bodies except for their brains and nervous systems. About four of them fall in to the same creature, and they discover that by thinking about it they can grow limbs and other body parts. At first they try to fight each other, by growing arms so they can hit each other's brains - and one of them realises that growing a skull would be a good idea - but later they agree to grow legs and move the creature around co-operatively. I would love to identify this story.