I am running Ubuntu 18.04. I installed eclipse from Ubuntu Software but when I run eclipse I get the error log:  !ENTRY org.eclipse.equinox.launcher 4 0 2018-05-20 19:19:03.099 !MESSAGE Exception launching the Eclipse Platform: !STACK java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter     at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)     at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:626)     at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)     at org.eclipse.equinox.launcher.Main.run(Main.java:1438)     at org.eclipse.equinox.launcher.Main.main(Main.java:1414)

I installed eclipse via Ubuntu Software. When I start it, it take some seconds and then comes an error window showing the path of the error.  The following is the .log file:  !SESSION Wed May 02 12:53:28 BRT 2018 ------------------------------------------ !ENTRY org.eclipse.equinox.launcher 4 0 2018-05-02 12:53:28.587 !MESSAGE Exception launching the Eclipse Platform: !STACK java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter     at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)     at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:626)     at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)     at org.eclipse.equinox.launcher.Main.run(Main.java:1438)     at org.eclipse.equinox.launcher.Main.main(Main.java:1414)   What is the problem and how can I fix it?


Sometimes I try snapping vertices to the closest neighbour but it doesn't work as the object is always off. I think I'm missing something. I applied all transformations already and the origin is at center. What could it be?  In this gif I'm trying to snap the angled pole to the bottom pole's low right (then left) corner with vertex snap. But as you can see it is off in all cases, even when I try to snap to vertices of different objects.

Why can't I snap the point I chose to the target point.  I tried for a long time to do this, but no use!  Could some help me? Thanks !


If I install Ubuntu on top of Windows 8.1, will it overwrite OS disk or entire hard-disk? Because I have so much data on my laptop.

I would like to see a full how-to guide on how to install Ubuntu.


Let $X$ be a topological space space and $X=\cup_{i\in I} U_i$ a covering of $X$ by open subsets $U_i\subseteq X$.     Is it true that   $$ \operatorname{colim}\left(\coprod_{(i,j)\in I\times I} U_i\cap U_j \rightrightarrows\coprod_{i\in I} U_i\right) \cong X $$   where the two maps are the inclusions of either $U_i\cap U_j$ into $U_i$ or $U_i\cap U_j$ into $U_j$? If this is not true in general, is it at least true for $X$ a CW-complex and $\cup_{i=0}^n U_i$ a finite good cover?

If I'm not mistaken, the pasting lemma for a two-element open cover $X=A\cup B$ of a topological space is equivalent to saying that the following square is a pushout in $\mathsf{Top}$: $$\begin{matrix} A\cup B & \longleftarrow & B \\ \uparrow && \uparrow \\ A & \longleftarrow & A\cap B\end{matrix}$$ where the arrows are the canonical embeddings.  Is my statement true, and if so, how can I categorically formulate the pasting lemma for general open covers $ \left\{  U_i\right\}  _{i\in I}$?


I have a HP 15 AC122TU laptop having dual OS as Ubuntu 16.04 and Windows 8.1.My problem is that it doesn't detect wifi sometimes. If connection established it may result in a low speed and poor range. No such problem in other Operating System.Please help me?

I've been trying to get Ubuntu to run on my HP 15-an000nd. It has been a huge pain all the way.  My last (big) remaining problem is Wi-Fi. The signal strength is very very weak.  lspci gives me the following concerning wireless:  02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 522a (rev 01) 03:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter 04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller (rev 0a)   I have tried the following:  sudo rmmod rtl8723be && sudo modprobe rtl8723be   and it tried to install these drivers:    I also set this parameter in the config file :   options rtl8723be fwlps=0   but nothing helps I still barely get any signal.  Any help is greatly appreciated, Greetings.


I have two File objects:   C:/basepath/ C:/basepath/directory/file.txt   Now I would like to subtract file 1 from file 2 so that I get directory/file.txt. I don't want to use String.substring() since file paths may differ from input.

Given two absolute paths, e.g.  /var/data/stuff/xyz.dat /var/data   How can one create a relative path that uses the second path as its base? In the example above, the result should be: ./stuff/xyz.dat


I have a custom post type that is created by an external plugin. This plugin uses the capabilities associated with posts. I want to add my own custom capabilities to this post type. I have seen plenty of examples of how to do this when registering a new post type but I can't add the capabilities at this point as otherwise the custom capabilities won't be there when I next update the plugin.  What would be the best way to add the capabilities after the custom post type has been created?  Thanks!

I'm using the plugin  which registers it's own post type but the capability is assigned to "post".   I want to change it to "manage_options".  Is there a correct way without altering the plugin to do that? Calling a hook, a function or whatever?   public function register_post_type() {      $labels = array (         'name'               => _x( 'Custom Code', 'post type general name' ),         'singular_name'      => _x( 'Custom Code', 'post type singular name' ),         'menu_name'          => _x( 'Custom CSS & JS', 'admin menu' ),         'name_admin_bar'     => _x( 'Custom Code', 'add new on admin bar' ),         'add_new'            => _x( 'Add Custom Code', 'add new' ),         'add_new_item'       => __( 'Add Custom Code' ),         'new_item'           => __( 'New Custom Code' ),         'edit_item'          => __( 'Edit Custom Code' ),         'view_item'          => __( 'View Custom Code' ),         'all_items'          => __( 'All Custom Code' ),         'search_items'       => __( 'Search Custom Code' ),         'parent_item_colon'  => __( 'Parent Custom Code:' ),         'not_found'          => __( 'No Custom Code found.' ),         'not_found_in_trash' => __( 'No Custom Code found in Trash.' ),     );     $args   = array (         'labels'              => $labels,         'description'         => __( 'Custom CSS and JS code' ),         'public'              => false,         'publicly_queryable'  => false,         'show_ui'             => true,         'show_in_menu'        => true,         'menu_position'       => 100,         'menu_icon'           => 'dashicons-plus-alt',         'query_var'           => false,         'rewrite'             => array ( 'slug' => 'custom-css-js' ),         'capability_type'     => 'post', // <--- I want to manipulate this         'has_archive'         => true,         'hierarchical'        => false,         'exclude_from_search' => true,         'menu_position'       => null,         'can_export'          => false,         'supports'            => array ( 'title' ),     );      register_post_type( 'custom-css-js', $args ); }   The above code is in custom-css-js.php lines 200-239.


What is the best Stack Exchange site to get feedback on e-mail hosting? In a nutshell, I'm trying to get some feedback on affordable email hosting providers to host 18,000+ e-mail accounts with some usage specifics. I tried asking this question on the Webmasters Stack Exchange as suggested in this meta post:  however my question was put on hold because it apparently appears to be off-topic.  Which Stack Exchange site can I ask this question on?  Note: I have specific requirements and am looking for an objective list of email hosting providers that meet these requirements, so this is not a subjective question.

I just got a question closed because it was rendered subjective by the moderators. The question is important to me and I believe other people would benefit. So, I ask the following non subjective question: on which site of the Stack Exchange ecosystem should I post  question?


I am submitting a manuscript to a journal. I wish to exclude a colleague from being the reviewer of the manuscript. The journal has a single blind review: authors are known, reviewers are anonymous.  Question in short: The reason for this exclusion request are personal (see below), and I'm not sure I want to expose those reasons. What is the most effective ways to exclude a reviewer whom you don't trust to make a fair judgement?  Personal reasons for exclusion request::   We had a couple of harsh interactions. She had criticized me personally, and  had short arguments about our different attitudes towards publishing, writing and research.    I believe she has already wrote a "reject" review on my manuscript (for a different venue). To my judgment, she has standards that are uncommon in my research community, and so would judge my work on unconventional higher standards. Her personality, in my view, is harsh and critical (and unpleasant) and so each of her judgments are prone to be more negative than others, on average. She is related to the area of my manuscript (I have cited her manuscript and given her full credit for the work she did), and from her point of view me publishing the manuscript would, psychologically, be a personal disappointment, because her related work has not been published.    Questions: 1. Can I ask the editor not to send it to her review?    Should I ask the editor for this? Would it benefit me? How can I explain my request, and should I explain it?   Notes:  i) I don't want to write any of the reasons I listed above! Because they are mostly personal! And would put me in a very unpleasant situation psychologically at least.  ii) I believe that the review process in general is very subjective, and so there is always a way to consider the same work in two opposite perspectives: positive and negative. I believe the reviewer I want to exclude would highlight the negatives, and diminish the positives. And recommend a rejection.    This question is different from:  ,  because the current question asks how to exclude a reviewer  irrespective of the justifications of this exclusion. In other words, I'm not asking what are "sound reasons to exclude a reviewer",  but rather HOW to exclude her, independent from the existence of sound reasons.  More details of the difference:  In  the term "sound" is probably meant to be an objective term. However I claim that the reviewing process is not an objective process at all. Thus, there are at least three different interpretations of :   What kind of reason would be regarded as sound by the editor of the journal?   Or   Is there a set of objective reasons that the scientific community views as legitimate to exclude a reviewer?   Or   What can I, as an author do, to exclude a reviewer, if I think he/she has a grudge against me, irrespective of the objective reality, or the justifications of this act of excluding the reviewer?   The OP has not clarified whether he/she means 1, 2, 3 or another question. These are all different questions. I'm asking 3.  =====  I cannot merge my account with I am a guest (which is also me) because I don't remember the email I used for "I am a guest".

I am about to submit a paper, and I'm asked whether I want anybody to be excluded from consideration as a reviewer. I also need to state a reason. I briefly considered listing someone who - I have reasons to believe - once reviewed a paper of mine by listing criticisms that were unspecific enough that I spent a very large amount of time just trying to figure out what they meant. Of course my guess could be wrong, and it seems unfair to label someone as a suboptimal reviewer based on a hunch. Which led me to wonder - what are some good reasons for asking for exclusion of a reviewer? And additionally, what would polite wordings be for each of these reasons?


I am wondering which is grammatically correct out of 'If there were more time' and 'If there was more time' or, if both are correct, whether one is preferred?  I believe it ought to be 'were' as the clause is in the subjunctive mood, however 'was' sounds significantly more correct to me (as a native English speaker from England). So which is it?  Searching an exact match in Google for each gives 4 million results for 'were' and 10 million results for 'was', though Google searches are not the basis for proper grammar.  While other questions cover 'If there were' vs 'If there was', this example seems to be a special case for me and I am interested in the choice specifically in the construction relating to 'time'.

Which of these sentences is correct, and why?   "What if the Moon was a Disco ball?" or  "What if the Moon were a Disco ball?"


I was wondering if you can share your opinions regarding these two theories about Star Wars: The Force Awakens. One is that Rey is actually the daughter of Luke Skywalker, and the second idea is that she is just an incarnation of the Midi-Chlorian, just like Anakin.

Throughout much of the movie, Rey losing her family and waiting for their return on Jakku is a great motivating force for her character.   Her romanticizing the Resistance and her eagerness and willing to join them, in addition to her natural gift with the Force, suggests that they are important.  So, who is Rey’s family?


While installing Kali (Dual Boot) the installation process could not detect network even after having all the drivers. Well after the installation is complete there were no wireless connection showing. I really tried a variety of things, but I couldn't fix the problem. Even after installing (unloading and loading) compat wireless it shows wlan0 and wlan1 but they couldn't detect any wireless network ever. wlan0 up commands are also seeming useless in my case. Please help me...  Thanks in advance :)

I just installed Kali Linux on Dell Inspiron 1545, and am unable to get wireless connection. I attempted the following root@kali:~# lspci -knn | grep Net -A2 0c:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] (rev 01)     Subsystem: Dell Wireless 1397 WLAN Mini-Card [1028:000c]  # apt-get install firmware-iwlwifi # modprobe -r iwlwifi; modprobe iwlwifi  I even tried commands I used when I installed Ubuntu on the same laptop sudo apt-get install bcmwl-kernel-source sudo modprobe -r b43 bcma sudo modprobe wl  How to fix? UPDATE I also ran sudo apt-get install kali-linux-wireless but I still cannot detect and connect to my home wi-fi. Thanks! Tried first solution I tried first solution, but when I go to Administration > System, I get package manager. I searched for everything Broadcom downloaded, installed, rebooted, but still no wireless. There has to be an easy solution ...... Am trying this,  I was getting errors with install. After I reboot, still no wireless detector. Update I'm trying all your suggestions .... seems I will have to read the links you provided. Who knew getting wireless would be so difficult! I will extend bounty time if possible.


I am working with Java and Postgresql server. I have never used it before. I am trying to create a REST API that receives http requests and stores them in a Postgresql server. Here is the endpoint I am trying to build.  @POST     @Consumes(MediaType.APPLICATION_JSON)     @Produces(MediaType.APPLICATION_JSON)     @Path("/validation")     public Response Validation(C2BUtils c2BUtils) {          PreparedStatement ps = null;         Connection conn = null;         conn = DBConnector.getPostgresSqlDBConnection();          try {             String insertValidationTxn = "INSERT INTO c2b(TransactionType,TransID,TransAmount,BusinessShortCode,BillRefNumber,InvoiceNumber,OrgAccountBalance,ThirdPartyTransID,MSISDN,FirstName,MiddleName,LastName,TransTime) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";             ps = conn.prepareStatement(insertValidationTxn);             ps.setString(1, c2BUtils.getTransactionType());             ps.setString(2, c2BUtils.getTransID());             ps.setDouble(3, c2BUtils.getTransAmount());             ps.setString(4, c2BUtils.getBusinessShortCode());             ps.setString(5, c2BUtils.getBillRefNumber());             ps.setString(6, c2BUtils.getInvoiceNumber());             ps.setDouble(7, c2BUtils.getOrgAccountBalance());             ps.setString(8, c2BUtils.getThirdPartyTransID());             ps.setString(9, c2BUtils.getMsisdn());             ps.setString(10, c2BUtils.getFirstName());             ps.setString(11, c2BUtils.getMiddleName());             ps.setString(12, c2BUtils.getLastName());             ps.setString(13, c2BUtils.getTransTime());             int add_detail = ps.executeUpdate();              if (add_detail == 1) {                 System.out.println("New tx " + c2BUtils.getTransID() + " added");             } else {                 System.out.println("no txn added");             }              conn.close();          } catch (Exception e) {             Logger lgr = Logger.getLogger(C2B.class.getName());             lgr.log(Level.SEVERE, e.getMessage(), e);             System.out.println("Message-->" + e.getMessage());         }         String re = "OK-2000";         return Response.status(201).entity(re).build();     }   Whenever I make an POST request , I get java.lang.NullPointerException and on the code it shows the error originates on this line   ps.setString(1, c2BUtils.getTransactionType());   I have tried to find out what the issue is without success. Any help will be 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 created this function that is supposed to replace all the white space within a string with the string "%20". ie: "Mr John Smith" becomes "Mr%20John%20Smith". To accomplish this, I placed all the characters of the string into an array and attempted to loop through, replacing any instance of " " with "%20". For some reason, the code I wrote doesn't seem to recognize the " " value within the list and skips over this part of my loop. So instead of getting a new String with the white spaces replaced, I simply get back the same string with the white spaces intact. Can anyone help correct my error? I ran it through the Java Tutor to visualize my code and it reflected this same error  import java.util.ArrayList;  public class Interview {      public static void main(String[] args) {          Interview theFunc = new Interview();          String d = "Mr John Smith   ";          System.out.print(theFunc.URLify(d, 13));      }     public String URLify(String str, int x){         String result = "";         String real = str.substring(0,x);         String [] list = new String[real.length()];         int i = 0;         while (i != real.length()) {             list[i] = real.substring(i,i+1);             i = i +1;            }         int b = 0;         while (b < list.length) {             if (list[b] == " ") {                 list[b] = "%20";                 b = b + 1;             }else{                 b = b + 1;             }         }         int d = 0;         while (d != list.length) {             result = result + list[d];             d =d + 1;         }      return result; }   The error is occurring in the second while loop. Thanks!

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?


I do not much about particle physics. But people say that neutron and proton are composed of quarks, and in turn a nucleus is composed of neutrons and protons.   Therefore, the question is, is this hierarchy necessarily well defined? Could we view a nucleus as a collection of quarks, without the in-between neutrons or protons?

This question may sound stupid but why do we visualize nuclei as composed of a bunch of neutrons and protons? Wouldn't the nucleons be too close together to be viewed as different particles? Isn't the whole nucleus just a complicated low energy state of QCD?


I am a class 12 student and I am Wondering about the Ramanujan summation Series that is 1+2+3+..... = -1/12. As per my knowledge Summation of positive number gives a positive number but in the Ramanujan summation Series value is negative. Can you please explain this in brief.

$\displaystyle\sum_{n=1}^\infty \frac{1}{n^s}$ only converges to $\zeta(s)$ if $\text{Re}(s) > 1$.  Why should analytically continuing to $\zeta(-1)$ give the right answer?


I bought a USB flash drive that reports it has more space than it really does.   How can I determine how much space it really has? Can I format it properly if I can get the above answer? Should I just return it and not try to salvage it?

Recently, I bought an USB flash drive which has a cool design.  The seller said it is 256GB however, I've already known that capacity would be fake. Anyway, I bought it cause of its cool design and want to use this USB flash drive anyway.  What should I do?  I've tried to find a proper tool(vid 1908 / pid 1320) but couldn't. Can I repair this through Low level format? Or partitioning this through Linux?


When developing my program, I was faced with this problem, as different types of classes after inheritance.   For example:  class MyClass: pass  class MyClass2(MyClass): pass  A = MyClass() B = MyClass2() print(type(A) == type(B))    Result will be False, and that's not what I need. I tried to search some info in typing Python module, but I didn't really understand nature of types. What should I do for True result?

What is the best way to check whether a given object is of a given type? How about checking whether the object inherits from a given type?  Let's say I have an object o. How do I check whether it's a str?


I have a world map divided into zones and need to compute the area for each polygon. I tried using Vector > Geometry Tools > Export/Add geometry columns and successfully get the area and perimeter but I don't know the units of this measurement.     I assumed this was in square meters because the Layer CRS is WGS84 and I have 'Units for area measurement' in Project > Project Properties set to square meters but it seemed off by couple orders of magnitude. If I assumed these measurements were in square kilometers the sum of all the areas is still off by about 20% from the earths surface area.

How do I calculate areas of an area shapefile in square meters (m²) or in acres (ha)? I didn't find that functionality in the Vector Tools.


I am trying to understand what is the effective accuracy of a georeferenced image and how to attach a standard to the georeferencing process which can be used for future reference. To explain further, I am trying to assess what kind of RMSE would be acceptable when for example georeferencing an accurate architects drawing with an aerial image, or with a small scale landuse plan drawn with thick outlines using parcel data with an accuracy of plus/minus 1cm.  If I am using an inaccurate base map in which to base my passpoints, does the rms error have any meaning whatsoever? Logically, is it not so, that one can only use the rmse as a standard when the accuracy of the basemap can be certified? If the base map is not accurate, any passpoints referenced to it would be even less accurate and an RMS error meaningless.  Am I on the right track?

This is a generic inquiry on the common practice/standard for determining the acceptable values of RMS when georeferencing topographic maps.  Is there an absolute value?  Some literature suggests that it should be "less than or equal to 1/2 of the side of a cell which make up the total resolution of the image."


I am stuck in the Lubuntu login loop where everytime I type my password the screen flashes white and I'm back to login.  I have attempted CTRL ALT FN+F3 to login to the shell but this just sends my screen black. CTRL ALT FN+F7 will get me back to login but I cannot proceed.  Please help me!

My Ubuntu is stuck in a login loop when trying to enter my desktop. When I login, the screen gets black and soon after that the login screen comes back.   I've read that the problem might be caused by an error depending on the graphics, here's my graphics card: ATI Radeon 7670M


I am getting month and its weekno like 1,2,3,4,5 . I want ISO week from it.  Eg. I have April as month and week no 4. I want weekno 16 as output.  Thanks in advance.

Given a week number, e.g. date -u +%W, how do you calculate the days in that week starting from Monday?  Example rfc-3339 output for week 40:  2008-10-06 2008-10-07 2008-10-08 2008-10-09 2008-10-10 2008-10-11 2008-10-12


Recently I keep on finding that when clicking the StackExchange pull-down menu which is at the top left hand corner of every site that instead of it giving me the pull-down menu options that it instead acts like a link which just redirects me to the the main  site. This is the pull-down menu button that I mean:    This appears to be some sort of bug which mostly occurs when the page has not fully loaded yet, and I guess that it has not realised that it is a pull-down menu and not a link. So I just thought that I should report it.

When I click the "hamburger menu" in the right part of the top bar:    I usually get the site switcher drop-down:    But sometimes, I'm taken to  instead:    It isn't very consistent.  I tend to get the drop-down if the page has been loaded for more than a few seconds.  I most often get the SE homepage if I click in the first couple seconds after the page loads, although sometimes I get the drop-down even if I click very quickly. But it doesn't always seem to happen.  When I started writing this question I had no trouble getting it to occur, five minutes later I couldn't reproduce it, and ten minutes later I could again.  At the moment my guess is that it's related to how quickly some page element loads. Being unable to predict the results of clicking the top-bar is somewhat confusing, although it does work most of the time, so it's not terribly frustrating. It took me a while to figure out that it wasn't my own fault—at first I thought that the "StackExchange" text linked to SE and the down arrow showed the drop down, and that the inconsistency was a result of my inaccurate clicks.  Doing some experimentation, it seems that this is not the case, and the entire rectangle (circled above in red) has the same behavior. I've observed this behavior in SeaMonkey 2.26 and Firefox 28, and Nick Stauner has reproduced the problem in Chrome 34 ().


I'm going to take Galois theory in the upcoming semester and I'm working on some basic problems right now. I was trying to figure out what $\mathrm{Aut}(\mathbb{C})$ should be. If $f: \mathbb{C} \to \mathbb{C}$ is an automorphism, then it's straightforward to see that $f(i) = \pm i$. Obviously, if I can prove that $f \mid_{\mathbb{R}}=\mathrm{id}_{\mathbb{R}}$, I'm done and $\mathrm{Aut}(\mathbb{C}) \cong \mathbb{Z}_2$.  However, no matter how much I struggled with the problem, I failed to prove that an automorphism of $\mathbb{C}$ must send real numbers to real numbers. In fact, now I even doubt that it's true. Is it possible for an automorphism of complex numbers to send a real number to a complex number? If yes, how exotic $\mathrm{Aut}(\mathbb{C})$ is? Is it uncountable, for example? Can we construct any of these automorphisms without relying on the axiom of choice?

I read about so called "wild" automorphisms of the field of complex numbers (i.e. not the identity nor the complex conjugation). I suppose they must be rather weird and I wonder whether someone could explain in the simplest possible way (please) how I could imagine such wild automorphisms.  E.g. I suppose they are completely discontinuous. E.g. are the real rational numbers fixed or any other set of complex numbers? Can such an automorphism be pictured in a model?


I have a form in PHP that submits data to MySQL.  Looking at the data in the database, I can see that around 2-3% of the rows contain international characters that are encoded incorrectly, e.g. "Guðrún" displays as "GuÃ°rÃºn".  But, another user might submit the same characters just a few minutes later, and in that case, the characters are encoded correctly  So it seems the encoding is dependent on the computer that is used or some other factor that I am unaware of.  In the head of the HTML, I have this:  <meta charset="ISO-8859-1">   The form has this:  <form autocomplete="on" method="post" action="index.php" id="form1" accept-charset="ISO-8859-1">   The MySQL columns are set to latin1_swedish_ci.  Is there something else I should be doing to make this work for everybody?  Edit: since it was marked as duplicate I can't find an answer to this question anywhere else. I've read through lots of info on character encoding, which led me to having the setup I currently have, but that doesn't explain why 2-3% of the data is behaving differently from the rest.

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I'm trying to mount a vdi file in ubuntu 13.10. I tried to  sudo apt-get install virtualbox-fuse   but it complains about not finding the package.  Converting it to raw is not really an option for me, I don't have enough free space.

I'm using 13.04 Raring amd64 and I need to mount a .vhd file on my ubuntu. I've googled about it and found that virtualbox-fuse package is the answer.  But the package was deleted from apt repository. Is there any way to install the package w/ 13.04? or is there any alternative to virtualbox-fuse?


When I am trying to start "cmd.exe" as a Administrator, it won't ask for password and I can execute commands.  Below code is working good, but it is asking Admin password.  Is there a way that it should resolve automatically and run under local admin account?   string subCommand = @"dir";         string subCommandArgs = @"c:\";         string subCommandFinal = @"cmd /K \""" + subCommand.Replace(@"\", @"\\") + " " + subCommandArgs.Replace(@"\", @"\\") + @"\""";         ProcessStartInfo procStartInfo = new ProcessStartInfo("runas.exe");         procStartInfo.UseShellExecute = true;         procStartInfo.CreateNoWindow = true;         string finalArgs = @"/env /user:Administrator """ + subCommandFinal + @"""";         procStartInfo.Arguments = finalArgs;         using (System.Diagnostics.Process proc = new System.Diagnostics.Process())         {             proc.StartInfo = procStartInfo;             proc.Start();         }

I'm trying to install a service using InstallUtil.exe but invoked through Process.Start. Here's the code:  ProcessStartInfo startInfo = new ProcessStartInfo (m_strInstallUtil, strExePath); System.Diagnostics.Process.Start (startInfo);   where m_strInstallUtil is the fully qualified path and exe to "InstallUtil.exe" and strExePath is the fully qualified path/name to my service.  Running the command line syntax from an elevated command prompt works; running from my app (using the above code) does not. I assume I'm dealing with some process elevation issue, so how would I run my process in an elevated state? Do I need to look at ShellExecute for this?  This is all on Windows Vista. I am running the process in the VS2008 debugger elevated to admin privilege.  I also tried setting startInfo.Verb = "runas"; but it didn't seem to solve the problem.


Is there any type in C#that would allow me to store a fractional number with arbitrary or infinite precision? I don't want to use any external libraries--would I have to write a class myself? How would I do this?  I need a variable to which I can apply the standard arithmetic operations, and get the result with as much precision as I want, something in which I could do something like calculate pi or another irrational number to a precision like 10,000 digits...

Currently I am . Having never used a library for working with large integers before, this seems slow, on the order of 10 times slower, even for ulong length numbers. Does anyone have any better (preferably free) libraries, or is this level of performance normal?


The Elder God N'Zoth's battlecry says:      "summon your deathrattle minions that died this game"   If this summons more minions than will fit on your side of the board, how does the game decide which minions will be summoned and which will not?

I'm wondering a point about N'Zoth. He will summon my dead deathrattle minions, but will he do it in a specific order (death order, mana cost order, ...) ? Or randomly ?  If there is already a few minions on my side of the board, I'd like to predict which minions will be summoned and which ones will not (because board is full). If it's by death order, this generally means lower cost minions (like fire bat) will be summoned before the interesting big drops (sylvanas, highmane or so).


I've got a situation where I have a callback from unmanaged code to managed C# code.  The C# code is throwing an exception and if I let it propagate back through the unmanaged code it gets silently ignored. In the callback I'd like to catch the exception and then force it to be treated like an unhandled exception - either breaking in the debugger, or aborting the process if not running under the debugger. What's the best way to handle this?  Or, are there any references to discussions about this issue? (I don't have control over the unmanaged code - it's a Win32 WndProc callback).

I would like Visual Studio to break when a handled exception happens (i.e. I don't just want to see a "First chance" message, I want to debug the actual exception).  e.g. I want the debugger to break at the exception:  try {    System.IO.File.Delete(someFilename); } catch (Exception) {    //we really don't care at runtime if the file couldn't be deleted }   I came across  notes for Visual Studio.NET:     1) In VS.NET go to the Debug Menu >>   "Exceptions..." >> "Common Language   Runtime Exceptions" >> "System" and   select "System.NullReferenceException"      2) In the bottom of that dialog there   is a "When the exception is thrown:"   group box, select "Break into the   debugger"       3) Run your scenario. When the   exception is thrown, the debugger will   stop and notify you with a dialog that   says something like:              "An exception of type "System.NullReferenceException" has   been thrown.              [Break] [Continue]"       Hit [Break]. This will put you on the   line of code that's causing the   problem.   But they do not apply to Visual Studio 2005 (there is no Exceptions option on the Debug menu).  Does anyone know where the find this options dialog in Visual Studio that the "When the exception is thrown" group box, with the option to "Break into the debugger"?  Update: The problem was that my Debug menu didn't have an Exceptions item. I customized the menu to manually add it.


To be specific, I have a solid background in college level math but I feel that I have trouble to understand what is number theory. As a first approximation, number theory studies integers. But it is of course not a complete answer. Somebody told me number theory in general studies "arithmetical properties" in algebraic systems. But this is not an answer for me but merely a paraphrase, since number theory=arithmetic. So what exactly number theory?  Let me put my question in another way, I cannot distinguish algebra from number theory.  Let me take geometry and topology as an example. These two areas are of course highly correlated. But I think I understand the difference: when we talk about geometry, the manifold should be equipped with metric. And curvature is extremely important in geometry. My understanding may be shallow here. But at least I find some key features like "metric", "curvature" geometrical but not topological.  But what's going on for number theory? I will greatly appreciate that someone can give a one sentence answer to distinguish number theory from algebra.  Edit: This question was marked as a duplicate of the question:  Subjects studied in number theory  They are similar but I think we are asking a question from different levels. I'm familiar with the basic number theory research subject such as prime distribution, zeta function, diophantine equation, etc.   But for the higher level number theory especially algebraic number theory, I fail to understand the key difference between number theory and general algebra.   For example, let me quote class field theory from wikipedia: "In mathematics, class field theory is a major branch of algebraic number theory that studies abelian extensions of number fields and function fields of curves over finite fields and arithmetic properties of such abelian extensions." After reading this, I will say uh-oh, why abelian extensions is number theory? Wouldn't it be algebra? What properties would be considered as "arithmetic property"?

I know little about number theory even after reading its Wikipedia article.    I was wondering if the subjects studied by number theory is only about integers or even more restrictedly natural numbers or prime numbers, and how they are related to other types of numbers such as rational and irrational numbers? In number theory, are the real numbers also studied? If yes, what aspects of real numbers are studied in number theory?   Are real numbers studied just as generalization from integers and rational numbers? Or are they also studied standalone independently of integers and rational numbers?  If they are also studied independently of integers and rational numbers, is the set of real numbers, $\mathbb{R}$, regarded as a 1-dim Hilbert space with dot product being inner product and the induced topology, just as how it is studied in real analysis? Is $\mathbb{R}^n,     n \in \mathbb{N}, n>1$ studied in number theory? Can I say what is studied in real analysis about real numbers is part of number theory?  When studied independently of integers and rational numbers, is $\mathbb{R}$ regarded  as a special kind of algebraic structure studied in abstract algebra? Similar questions for complex numbers, to those for real numbers in 2. Especially are there differences between how complex numbers are studied in complex analysis, in algebra, and in number theory?    Thanks and regards!


Here is a paradox I have some difficulty resolving:  As far as I understand, by one of Gödel's incompleteness theorems, in a first order logic theory with Peano arithmetic, one can find some non-trivial universal closed sentences (starting with a "for all" quantifier, all variables being bound) that can be proven to be unprovable.  Consider such an unprovable universal statement of the form "For all x, P(x)". We proved that there can be no counter example of this statement, exactly because finding such a counter example would disprove the statement hence contradicting Gödel's theorem which said that this statement can not be proven nor disproven. Therefore the given statement must be true.  As one can observe, my previous paragraph is a valid sequence of arguments that explain why my considered universal statement must be true. This previous paragraph is, by the very definition of proof, a proof of the given statement. My conclusion is that either Gödel was wrong, or mathematics are inconsistent :)  What is wrong with my reasoning ? Can you explain why the second paragraph would not be a valid proof? Does it have something to do with metalanguage? Even if metalanguage is mixed with regular language, cannot all the metalanguage used here be encoded in a first order logic with Peano arithmetic, and seen as not part of a stronger theory ?

Godel`s incompleteness theorem states that there may exist true statements which have no proofs in a formal system of particular axioms. Here I have two questions; 1) How can we say that a statement is true without a proof? 2) What has the self reference to do with this? Godel sentence "G" can say that SUB(a,a, no prove) but could be this just arbitrarily judgement about non-provability of "a" because it may simply has a proof which is not yet revealed or discovered?


How do I put a tilde directly underneath an inequality (i.e. directly beneath < or >)?

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


I am trying to delete "Games" folder. Folder size is huge. But it's not deleting. Even not showing a message.  If I try to delete using cmd. But it shows another error.    What should I do now?

I plugged my USB flash memory stick into a Mac and it gained some unwanted hidden folders. (See the question  for prevention.)  I'd now like to remove these from my drive but I ran into an issue. Inside the fseventsd folder is a subfolder that is not shown unless I disable "Hide protected operating system files" in folder options. I am then shown a folder icon with no name, and attempting to delete it results in no action and no error. Attempting to open it results in the error:     E:\fseventsd\ is not accessible      The filename, directory name, or volume label syntax is incorrect.   So I took a look using command prompt:    I must admit, had I not known the parent folder was from Mac OSX I would have strongly suspected a virus, because the folder name renders as a smiley face in ASCII.  Apparently this is ASCII character "01":    Any commands I issued in Command Prompt resulted in various syntax errors as well. I decided to try Powershell.  Unfortunately 1) I'm not very experienced with Powershell, and 2) it appears to have similar difficulty with the weird folder name. I got the following error in Powershell just trying to list the parent directory contents:     Get-ChildItem : Illegal characters in path.     How can I delete this folder?


How to install Micromax MMX 354G USB in Ubuntu 10.04

I want the driver software for my Micromax 352g USB modem for Ubuntu 12.04 LTS. On Ubuntu 10.04 sakis3g was working well, but it is not working on Ubuntu 12.04 LTS.


Is there a license-free technology that can export rasters from an ESRI File Geodatabase to a file-based raster (e.g. GeoTIFF or IMG file)?   ESRI has the  for "reading" the contents of a file geodatabase, but it has very few features for rasters. GDAL has some extensions for file geodatabase, but I've been unable to find one that can export the rasters.

I'm looking for a way to access raster layers in an Esri File-GeoDatabase without using ArcObjects or ArcPy, specifically I would like to access the raster layers with GDAL. I understand that the GDAL FileGDB and OpenFileGDB give access to vector datasets within File-GeoDatabases, and that ESRI's own FileGDB C++ API does not support raster access.   Is anyone out there aware of any open source solutions?


I'm making an earth in blender and the edge of the night is wavy and sharp. and here is the picture of the shader editor.

I've been modeling a hermit crab and I don't know why but some areas of the mesh are really dark on some spots, like the legs and the claws.   I hope you can help me fix it.


So, basically I just joined a community and posted some stuffs there. Then I wanted my nickname to be different on that community, since one is "professional" and the other is more "personal" oriented.  The thing is, someone commented my answer and greeted me using my old nickname. When I asked if this person could edit his comment, it was not possible for him to do so after more of 5min.  Here is a link for your understanding :   My question are :   Is it possible for someone in the community to edit comments ?   How could I notify someone that my privacy has been "hurt" and take action to restore it?

I just posted a comment to someone's answer on SO and accidentally left off the very first backtick, resulting in a really messed up looking comment. Of course I couldn't see the result of that omission until I posted it and by then it was too late to fix it. Is there anything I can do to fix it?


Prove that $g(x)=\begin{cases}x^2&x\in\mathbb Q\\0&x\in\mathbb R\setminus \mathbb Q \end{cases}$ is differentiable at $x=0$.

$f:\mathbb{R} \to  \mathbb{R}$ be defined as  $f(x)$= $x^2 , x \in \mathbb{Q} \\ 0 \ \ , x \in \mathbb{Q^c}\\ $  How to show that $f$ is differentiable at $x=0.$  I want to try this approach.  here  $f'(x)=$ $2x  \in \mathbb{Q}  \\  0  \in \mathbb{Q^c} $  since $lt \\ x \to 0+$$f(x)$ = $lt \\ x \to 0-$$f(x)= 0$   so $f$ is differentiable at $x=0$


What happens?  Several times has happened to me that I try to find a question (or solution) in Google or Stack Overfow, and nothing. Then I ask the question and, very fast the question is marked as [Duplicated]. Is this a good mechanism? It is right to ask a question for finding another one? In my case, this last time happened to me asking:  Difference between Asp.net MVC 4 Controller's Actions and WebApi's Actions [duplicate] when already was asked before like this one: Difference between ApiController and Controller in ASP.NET MVC    EDIT    So, it is a good practice remove the duplicated question? (like I did)

Possible Duplicate:          The following series of events happened to me today for about the 100th time:   I have a programming question I cannot answer. I search Stackoverflow for the right question and hope it has good answers. Finding none, I google, which often yields better stackoverflow hits (related: why is that?). I think more about the question, rephrase it, and repeat the above steps. Finally, I click "Ask Question" on the stack, and type the title for my question. Upon tabbing from the title, I find my question in the "Related Questions" section!   While this is a happy moment, I can't help but think that one of my six or seven searches should have found it for me. Has anyone else had the same experience?


I am tapping into the output voltages (signal wire) of various sensors on a vehicle, and I would like to use decoupling capacitors to filter out noise.  As others have stated, a rule of thumb is to use a 0.1uf and 10uf capacitors.   My question is related to how the 2 capacitors work together. Based on what I put together, the capacitors have a very high impedance at certain frequencies (or ranges) and therefore block them. I found a 10uf cap and a 0.33uf cap datasheets  with plots of frequency vs impedance (had difficulty finding a 0.1uf plot.)  I think the best way to phrase my question is this;  What happens if I use the following 2 capacitors in parallel (10uf and 0.33uf) for noise filtering a DC analog signal with an approximate noise frequency of:   10Hz 0.001MHz 0.8MHz (corresponds to min impedance of 0.33uf cap) 6MHz (corresponds to min impedance of 10uf cap) 5) 100MHz     EDIT: Bad question, i need a low pass filter and not decoupling capacitors. At-least now i know about Anti-Resonance in case i need it in the future.

My quesiton: Is it better practice to put same-valued capacitors in parallel of capacitors of different values to decouple the high-frequency noise caused by digital ICs? Background Digital IC need a decoupling capacitor close to their supply pins to ensure a stable voltage during power transients and to deal with noise (mostly to prevent noise generated by the IC to affect neighboring circuitry). It seems sensible to place a bulk capacitor (say 10-100uF), to act as an energy reservoir, and several smaller capacitors to deal with higher frequencies. The reason to place several small capacitors instead of just one is to deal with their Equivalent Series Inductance (ESL), which in practice, causes them to behave like an LC circuit. The effect of anti-resonance Yet, here is where best design practices and electronic myth seem to get mixed up and confusing to me. Most electronic engineers I have met like placing several decoupling capacitors of different values in parallel (with the smaller capacitors closer to the IC). The logic behind it is that the each capacitor takes care of a different noise frequency as depicted in Figure 1.  Figure 1: Impedance over frequency of three different value capacitors in parallel (cyan) vs their individual contribution (brown, blue, red). Image taken from . Note the small anti-resonance peak. It seams no major trouble , and the overall behavior of the three different capacitors in parallel is vastly superior to their individual decoupling capabilities. However, I have read in  by [Henry W. Ott] that placing capacitors of different values may cause a much greater antiresonance-peak which can be very harmful for our designs (see Figure 2). In fact, it amplifies any noise that falls into the anti-resoance frequency range, which is corroborated by .  Figure 2: from Electromagnetic Compatibility Engineering, by Henry W. Ott, section 11.4.4. The 15nH inductance makes reference to the capacitors ESL.


I wanted to use Ubuntu for the first time for deep learning purposes. I made a partition and installed Ubuntu on it. For some reason, the system booted straight to Windows. But after much tweaking, I managed to boot to GRUB only to realize that Windows 10 is not an option there. I don't know much about Linux so please pardon me.   I can see the Windows data files in the file explorer in Ubuntu.  fdisk-l shows    update-grub shows    os-prober shows no output.  I know there are many threads like this but I can't find the solution that works as of now.  I have tried editing /etc/grub.d/40_custom to contain this:  menuentry "Windows 10" {    set root='{hd0,1}'    chainloader + 1 }   This creates an entry, but I can't load Windows. Thanks in advance.

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


Why does:  [ "a" != "$(printf "\na")" ] && echo true || echo false   print true while:  [ "a" != "$(printf "\n")a" ] && echo true || echo false   print false?

The following code best describes the situation.  Why is the last line not outputting the trailing newline char?  Each line's output is shown in the comment.  I'm using GNU bash, version 4.1.5          echo -n $'a\nb\n'                  | xxd -p  # 610a620a              x=$'a\nb\n'   ; echo -n "$x" | xxd -p  # 610a620a      echo -ne "a\nb\n"                  | xxd -p  # 610a620a x="$(echo -ne "a\nb\n")" ; echo -n "$x" | xxd -p  # 610a62


I want to prove that $$\int_0^1x^{-x}dx=\sum_{n=1}^\infty n^{-n}$$ And I know that $$x^{-x}=e^{-x\log x}$$ and $$e^u=\sum_{n=0}^\infty \frac{u^n}{n!}$$ I get that $$x^{-x}=\sum_{n=1}^\infty \frac{(-x\log x)^n}{n!}$$   Then I have no idea how to prove the rest of it. Any suggestion? Thanks!

Earlier today, I was talking with my friend about some "cool" infinite series and the value they converge to like the Basel problem, Madhava-Leibniz formula for $\pi/4, \log 2$ and similar alternating series etc.  One series that popped into our discussion was $\sum\limits_{n=1}^{\infty} \frac{1}{n^n}$.  Proving the convergence of this series is trivial but finding the value to which converges has defied me so far. Mathematica says this series converges to $\approx 1.29129$.  I tried Googling about this series and found very little information about this series (which is actually surprising since the series looks cool enough to arise in some context).  We were joking that it should have something to do with $\pi,e,\phi,\gamma$ or at the least it must be a transcendental number :-).  My questions are:   What does this series converge to? Does this series arise in any context and are there interesting trivia to be known about this series?   I am actually slightly puzzled that I have not been able to find much about this series on the Internet. (At least my Google search did not yield any interesting results).


Recently, I decided to install the loved Linux Mint. I made sure I had space for a partition, and installed it. I am currently on the "trial" part, where it has "Install Linux Mint" on the desktop. I have installed it, and it even has a partition saying "Linux Mint 16 Petra". Yet, when I boot it from HDD/SSD, there is no option to boot to Mint, only my old, broken, ubuntu distro and of course, the dreaded Windows.  I am not sure why this is happening, can anyone do any explaining? I have googled it but haven't found any answers.  Note: After doing fdisk l I got the following message:  `Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xd2f26588     Device Boot      Start         End      Blocks   Id  System /dev/sda1   *        2048     3074047     1536000   27  Hidden NTFS WinRE /dev/sda2         3074048   599508991   298217472    7  HPFS/NTFS/exFAT /dev/sda3       599508992   625141759    12816384   83  Linux  Disk /dev/sdb: 4000 MB, 4000317440 bytes 255 heads, 63 sectors/track, 486 cylinders, total 7813120 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000     Device Boot      Start         End      Blocks   Id  System /dev/sdb1   *         128     7813119     3906496    b  W95 FAT32`   Note: I am zach, I recently just remembered my old account.  EDIT: I forgot to show you guys what I got for the answer:  mint ~ # grub-install --boot-directory=/mnt/boot /dev/sdb grub-probe: error: failed to get canonical path of /cow. Path `/mnt/boot/grub' is not readable by GRUB on boot. Installation is impossible. Aborting.  mint ~ # mount /dev/sdb1 /mnt mount: /dev/sdb1 already mounted or /mnt busy mount: according to mtab, /dev/sdb1 is mounted on /cdrom   EDIT2: After performing Graeme's updated answer, No serious errors are there. Now what should I do?

So I started out with a 250GB HDD, the stock drive from an EeePC 1015pem that I am trying to turn into a MintBook. The drive is physically operable, but all data has been nuked, including the old OS. Given this, I attached the HDD to my desktop and installed Linux Mint 16 Xfce from a live USB created through Unetbootin-585. Set aside 10GB for swap and 240GB for ext4 and /.  The drive now refuses to boot for either the desktop or netbook. Both motherboards are sounding the correct sequence of beeps, so they seem healthy, and I can successfully access the BIOS on both systems. However, the only thing that comes up after starting the computer is a nonresponsive command-line. There is no error message, no grub or grub-rescue, nothing.  Is there anything I can try besides reformatting and starting over? How would I go about installing a boot loader that can boot my OS?


In Avengers: Infinity War Thanos was building the Infinity Gauntlet to annihilate half of the living beings.       After he collected all the Infinity Stones, he snapped his fingers and unleashed the wave.   Was he immune to the annihilation, or unleashing it was for Thanos like pulling the trigger in Russian roulette with 50% chance of committing the suicide?

Although my question is based on the comic mini-series Infinity Gauntlet issues #1 through 6, I'm open to any and all answers (i.e Movies, other comic books etc. etc.) across the Marvel multi-verse.   It was elegantly presented in the Infinity Gauntlet series how Thanos, after collecting all the soul gems snaps his fingers and destroys half the universe.  Additionally, in the recent movie Avengers: Infinity War,       Thanos does it again! He snaps his fingers and destroys half the universe.   However, one thing is unclear to me. In both cases,      Half the universe is destroyed (or obliterated, or erased from existence).   But who decides which half of the universe should not exist anymore? Does the wielder of the Gauntlet choose, or is the Gauntlet (along with the stones) sentient enough to make the decision?


I've noticed two tags being used for the same purpose on Stack Overflow.  Is there a place where I can request a fix?

I had raised a  to merge pre-build-event, and pre-buildevent; and postbuild-event and post-build-event. That was about 11 months ago, and I still see these two tags even now.  How are tag merge requests handled? Is there a better way for tag merge requests other than posting on Meta?


Imagine you have the following df: dffinal =  {'BTW': '2.81', 'ExclBTW': '31.17', Totaal: '33.98'}      BTW     ExclBTW Totaal   0   2.81    31.17   33.98     dtype: I want to do a reconciliation check on these numbers, such that Totaal equals ExclBTW + BTW: dffinal['VATcheck'] = np.where(dffinal['Totaal'].astype('float') == (dffinal['ExclBTW'].astype(float) + dffinal['BTW'].astype(float)), True, False)  However, the VATcheck returns False, while 2.81 + 31.17 = 33.98:      BTW    ExclBTW Totaal  VATcheck 0   2.81    31.17   33.98   False  What am I doing wrong here? Please help!

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I want to create a shape that looks like this:    I have the following code  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage{tikz}  \begin{document}  \begin{tikzpicture}[     inout/.style={       rectangle,       draw,       minimum size=1cm,       inner sep=2pt     }   ]     \node[inout] (d1) at (1,1) {in}; \end{tikzpicture}  \end{document}   which produces this:    How do I add the lines? This is meant to be a custom shape for a circuit.  Thanks!  Note: I looked at the  of this question and didn't find it very helpful. The question itself wasn't very related (it didn't answer my line question in a way I could understand) and the documentation it provided I found very difficult. If someone could provide a simple explanation, that would be really helpful.

I am currently learning how to use TikZ/PGF to make some figures for a project report, and so I have a question:     Is there is a practical way of making a particular object into a node?   The object I have in mind is shown in the Figure below. I want the object to consist in the big circle, the two circular arcs, the label and anchors at north, south, east and west. The dotted lines are simply there to indicate that I am going to have paths going out of these points, which is why I need the anchors there.     I include the source, in the case that it is useful to anyone.  \begin{tikzpicture} \draw[help lines, gray, dotted] (-2,-2) grid (2,2);  \begin{scope}[shift={ (0,0) } ]     \begin{scope}[rotate=90]         \draw[thick] (-1,0) arc[start angle=-90, delta angle=90, %                               x radius=1, y radius=1] -- (0,1) %NW                      (0,-1) arc[start angle=180, delta angle=-90, %                                    x radius=1, y radius=1] -- (1,0); %SE         \draw[gray] (0,0) circle (1);     \end{scope} % Anchor replacements     \node(N1)       at (0,1)    {};     \node(S1)       at (0,-1)   {};     \node(E1)       at (1,0)    {};     \node(W1)       at (-1,0)   {}; % Label     \node(Crossing number) at (0,0) {1}; \end{scope}  \path[thick, gray, dotted] [ out=90,   in=270]     (N1.center) edge (0,2) [ out=180,  in=0]       (W1.center) edge (-2,0) [ out=270,  in=90]      (S1.center) edge (0,-2) [ out=360,  in=180]     (E1.center) edge (2,0); \end{tikzpicture}   PS. I have had a look at the Manual, but I could not find a description of how to do this.


I have this:    This is my latex code  \documentclass[tikz,border=10pt,12pt]{standalone}  \usetikzlibrary{arrows}  \usepackage{pstricks}  \usetikzlibrary{calc}  \newcommand*\circled[1]{\tikz[baseline=(char.base)]{     \node[shape=circle,fill=blue!20,draw,inner sep=2pt] (char) {#1};}}  \begin{document}  \begin{tikzpicture}[>=stealth']  % Locations \def\ClientToServer{++(9,0)} \def\ServerToClient{++(-9,0)} \def\Lifeline{++(0,-15)}%Longitud hacia abajo  % Lifelines \path (0,0)           node[draw] (Client) {\blue{\textbf{Client}}} \ClientToServer node[draw] (Server) {\blue{\textbf{Server}}}; \draw (Client) -- \Lifeline (Server) -- \Lifeline;  % Blocks \path (Server) ++(0,-1) node (BeginProcess) {} node[below right] {} ++(0,-1) node (EndProcess)   {};   % Calls \draw[->] (BeginProcess)\ServerToClient -- node[above] {\circled{1} one}  (BeginProcess);  \draw[->] (EndProcess) -- node[above] {\circled{2} two } \ServerToClient;  \node[left=0mm,yshift=-3cm] {\circled{3} yesss};  \node[left=0mm,yshift=-5cm] {\parbox{1.7in}{\circled{4} hello hello hello hello hello}};  draw[->] (9,-6) -- node[above] {uiiiiuuuuuuuuuuuuuuuuu} (-9,-6);%<---- ?  \node (B1) [fill,color=black,text width=1.2cm] at (9,-15) {}; \node (B2) [fill,color=black,text width=1.2cm] at (0,-15) {};   \end{tikzpicture}  \end{document}   I want to generate more arrows between client-server and server-client. But no more is generated. I use basic commands like:draw[->] (9,-6) -- node[above] {uiiiiuuuuuuuuuuuuuuuuu} (-9,-6); but not generate.  I want can create more arrow like:  Thank you!

I need to draw this kind of simple sequency diagram, but I'm not very good with TikZ:    \begin{figure}[!ht] \begin{center} \begin{tikzpicture}[node distance=2cm,auto,>=stealth']     \node[] (server) {server};     \node[left = of server] (client) {client};     \node[below of=server, node distance=5cm] (server_ground) {};     \node[below of=client, node distance=5cm] (client_ground) {};     %     \draw (client) -- (client_ground);     \draw (server) -- (server_ground);     \draw[->] ([yshift=-1cm]client.south) -- ([yshift=-1cm]server.south);     \draw[->] ([yshift=-1.5cm]server.south) -- ([yshift=-1.5cm]client.south); \end{tikzpicture}   I also want the lines to be straight and have text over them.


How do you control when the fluid animation starts and stops? Because I want it to start a couple seconds in and then stop a few seconds later.

I have fluid simulation with an inflow object. I want the inflow to go for 2 seconds, then have the inflow stop (so no more fluid is added) but keep the simulation going  (so the existing fluid sloshes around).  However, I do not see any way to set start and ending values on my inflow object.  How do I stop inflow at a certain frame/time in my simulation?


I have a DSLR and when I take photos at night or in low light I have noticed bright spots will be seen a second time somewhere else in the picture.  Almost like a reflection within the picture itself.  I first noticed it when taking pictures of the moon.  How do I stop this?

I've purchased a Canon EF 50mm f/1.8 II. But I'm really disappointed in the results, especially when using it for night photography. :(  In my night shots a lot of lens flare appears in my photos. I've tried to change the angle and position of the camera to no avail. Also I cannot do any night photo without directing my camera to direct light like in street photography!  This photo was taken with my Canon 650D and 50mm 1.8 Lens in a long exposure night shot, and as you notice there is a bunch of lens flare in it. Some people suggested I remove the UV filter. This decreased the lens flare a little but there is still some flare in the photo .    I want to know if there is a problem with the lens? Or is this normal for a $100 lens? Does anyone else have a similar experience with this lens?


I'm studying elementary level of algebra and I'm trying to prove that the commutator subgroup of a nonabelian simple group is the original group itself. It is trivially false if the group is abelian, but I can't prove it when the group is nonabelian. The definition of the commutator subgroup of $G$ is $\{a^{-1}b^{-1}ab \mid a, b \in G\}$.

True or False: (19h.) The commutator subgroup of a simple group G must be G itself.      Answer: i think 3.pdf   False. G must be nonabelian.   I wrote the relevant definitions . Because $G$ is simple hence $N = \{id\}$ or $G$. The hinge looks like  hence I want to use it.    Possibility 1: If $N = \{id\}$, then $G/N = G/\{id\} \quad \simeq G$. How to sally forth?   Possibility 2:  If $N = G$, then $G/G = \{G\} \quad \simeq \{id\}$. How to sally forth?   (3.) What's the intuition?


Is there any way to get my old account + metadata back if I have lost an account ties to MyOpenID?

I've an existing StackExchange account with the following myOpenId: sidharth-panwar.myopenid.com  But I'm not able to log in with this account. Whenever I try to log in it gives me the following error message:       No OpenID endpoint found.     I've logged in with a temporary account (using my GMail account). Is it possible to link my GMail account with my myOpenId account so that my profile remains intact?  I've gone through the following threads already before posting:


If I define a constant function on domain of rationals, then is it the right chosen function to be continuous at rationals? Also is there any function with Domain of reals which is continuous on rationals?

The famous Thomae's function provides an example which is continuous only on irrationals. Similarly, can we have a function which is continuous only on rationals and nowhere else?


first of all, I want to say that I've read many threads to this topic and tried different suggestions to solve this problem but I did not succeed.  I still got this warning while compiling:     destination with the same identifier (name{page.2}) has been already used, duplicate ignored<to be read again> \relax l.31 [2]) [3] [4   My document is of type \documentclass[twoside, openright, 12pt]{book}. It has an unnumbered title page followed by an unnumbered blank page. Then I have i, ii, iii, iv and after this pages 1 to n.  I first got the problem after I copied some LaTeX code from another project into my project, so I thought the problem is about things like \cite. But then I figured out, that it also occurs when I simply write text. The warnings point to my empty lines. Is it possible that there is something wrong with my line breaks (double enter)?  I use a template of my university, there are many \usepackage and other commands. I don't know if I should post everything?! Tell me which information you need.  I include hyperref like this:  \usepackage[plainpages=false,pdfpagelabels]{hyperref} \hypersetup{     pdftitle={ein interessantes Thema},     pdfsubject={Bachelor-/Studienjahres-/Master-/Diplomarbeit},     pdfauthor={Max Mustermann},     pdfborder={0 0 0} }   (As you can see, I use the parameters plainpages=false and pdfpagelabels.)  I would be very thankful if someone could help me solving this issue!  Lukas    EDIT: But there is a further problem I thougt it was related to this topic: When I make paragraphs in my text, I expect them to look like this:  This is the case in some situations but in some other cases it looks different:   Where does the spacing come from?

I get the following warning   pdfTeX warning (ext4): destination with the same identifier (name{page.1}) has been already used, duplicate ignored    when compiling the following document:  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage{hyperref}  \title{[Title]} \author{N.N.}  \begin{document}  \begin{titlepage} \maketitle \thispagestyle{empty} \end{titlepage}  \tableofcontents \thispagestyle{empty}  \newpage  \section{[Section]}  \end{document}   I have tried find ways to get rid of this warning by searching in other places and I have read  and the other question in this place .


I was using a GLM but am happy with other models. Fake example: Lets say I have a response such as income. I want to include GED as a factor (0 or 1), but I also have 'parental income' that I only want to apply to people that have a GED. I am mainly modelling against 'time being in employment', with other factors to consider. What is the best way to do this? Would it be stratify into two subgroups and then model them? I feel like I would lose the relationship between the two groups. Or if there a way to alter model for this? I am an R user if that helps...

Consider a statistical problem where you have a response variable that you want to describe conditional on an explanatory variable and a nested variable, where the nested variable only arises as a meaningful variable for particular values of the explanatory variable.  In cases where the explanatory variable does not admit a meaningful nested variable, the latter is usually coded either as NA in the data set, or if it is coded with a value, that value is merely a placeholder that does not have any meaningful interpretation.  This situation tends to arise whenever you have an explanatory variable indicating the existence of a thing, and one or more nested variables describing the characteristics of that thing.  Some examples of this kind of situation in statistical problems are the following:   The explanatory variable is an indicator of whether a survey participant is married, and the nested variable is some characteristic of the spouse (e.g., education, age, etc.); The explanatory variable is an indicator of the presence of an item in a space, and the nested variable is a measure of some characteristic of the item (e.g., size, distance, etc.); The explanatory variable is an indicator of the occurrence of an event and the nested variable is a description of some characteristic of the event (e.g., duration, magnitude, etc.).   In these kinds of situations, we often want to build a regression-type model (in the broad sense that includes GLMs, GLMMs, etc.) describing the relationship between the response variable and the other variables.  It is not obvious how to deal with the nested variable in this type of model.  Question: How do we deal with the nested variable in this type of model?    Note: This question is designed to give a generalised answer to a recurring question on  regarding nested variables in regression (see e.g., , ,  and ).  This question is designed to give a generalised context-independent example of this problem.


I am directly quoting a sentence from an ebook. Thus, I want to add the page numbering to its citation. However, different to the print version, which I do not have, this ebook (Amazon Kindle version) does not have page numberings but rather "positions".  Do I just pretend it's a page numbering and note in the bibliography that it is a Kindle version? Or is there another way?  In case this is of interest, I am using Latex with Bibtex.

I got the following info from the  website in relation to citing Kindle books or ebooks.     If no fixed page numbers are available, you can include a section title or a chapter or other number.   I am wondering is there a preferred method of citing in this case?   I am history Mlitt student and have only recently started to use a kindle for research purposes. At the moment I use the loc (location) reference that is produced by the kindle in the notes text file you can download from it, that shows all your highlights/bookmarks, but I am confused as to the proper citation method as my supervisor queried if this was the standard way of citing a kindle. I have a copy of my history department style-sheet but it makes no reference to kindle editions.


What is the sarcastic English word to describe a highly paid job but with no responsibilities?

What is the word used to describe a job given to a person just to give him/her the status of being in employment? The role does not effectively fulfil a purpose other than status and prestige. I read this word in an article months ago and have not been able to find it. I am referring to an adjective, not nepotism or tokenism, and the concept is more general.  Example sentence:     Jim has a |word| job, it was given to him just to give him status and prestige.


There's two servers with the same network IP, and the only difference between them is the last two numbers like: xx.xx.15.247 and xx.xx.66.178   When i try the command Tracert (Traceroute) to test the ping and to see what hops does it take to reach the destination server, i get different ping times and different forward path results which is strange because they are all located in the same company host.  Is there something wrong? Shouldn't it take the same path too?

There's two servers with the same network IP, and the only difference between them is the last two numbers like: 37.211.15.247 and 37.211.166.178. The Hosting Provider claims that the subnet mask for both networks is 255.254.0.0  When I try the command Tracert (Traceroute) to test the ping and to see what hops does it take to reach the destination server, I get different ping times and different forward path results which is strange because they are all located in the same company host.  Is there something wrong? Shouldn’t it take the same path too?  I have added the the full IP addresses to both servers as requested by some commenters. Well the two servers aren’t “International” anyways, so as far as I know, the only thing that comes to mind is the possibility that the two are configured on different subnetworks just like what . Though it’s suspicious.  UPDATE: After doing so much research, I found out the Subnet of these two hosts. They are on a /15 (255.254.0.0) subnet mask. Unfortunately, this is what that hosting provider claimed to me which is not true, and the true Subnet they apparently use is a /17 (255.255.128.0) Subnet mask. It turns out that they were definitely on different Subnets. That's why I got different traceroutes when I tested these two IPs 37.211.15.247 and 37.211.166.178  because they are clearly on different Subnets. Thank you everyone for these good answers, especially  his answer helped me a lot.


How does one solve for sine, cosine, or tangent (and inverse sine, cosine, tangent) without the use of a calculatour? For example: cosine of 131 degrees — how must one calculate this?

To give some background to the question, I am preparing for an admissions test for a physics course at university (the ), and for this test we are not allowed to use calculators or tables in any form.  In the maths section of the test, there are often trigonmetric equations such as the one below which we have to solve for $x$ within a certain range (usually $[0,\pi]$):     Solve $\sin{3x}=\sqrt{3}\cos{3x}$, for $x$ in the range $0\leq x \leq \pi$.   This problem is easy to reduce:  $$\tan{3x}=\sqrt{3}\implies3x=\tan^{-1}{\sqrt{3}}\implies x=\frac{\tan^{-1}{\sqrt{3}}}{3}$$  However, I am unsure how I can evaluate expressions such as $\tan^{-1}{\sqrt{3}}$ without a calculator, is there any method I can use for expressions like these, or am I required to simply learn various common values of $\tan$ (i.e. $\tan{\pi}$, $\tan{\frac{\pi}{4}}$, $\tan{0}$, etc.)?  Thanks in advance!


so I accidentally deleted my ubuntu hard drive off windows and I created a new partition and now my system will not properly boot up into Windows. I have to hit F12 and click on the Windows Boot Manager option , otherwise my system will boot into GRUB. I did some research on the forums and found that I have to get a Windows 10 pendrive and just go to the repair, and insert in the command line both  "bootrec.exe /fixmbr" & "BootRec.exe /fixboot" but that does not seem to solve my problem. Any thoughts on this? Thanks in advance

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


I draw the equation in  wolframalpha.com but I don't know how can determine correct answer please I really need help to understand the difference:

how can I draw the graph for this   the graph of $x \geq 5$ and $y \geq5$ is?  please guide me to draw it   thanks in advance


I just want know if there is some way to talk or to claim something to a moderator/moderators if there is something I am not satisfied with. For example, a special room for moderators, an mailing system, a ask-a-moderator button or something like that?  This is just to enable communications between users for they which will be satisfied and will know the usability of the site and solve their problems.   Actually, I have someone who voted me up and I got the voting up reversed, and I don't know if it's a Stack Exchange spider, or not, and if it's a Stack Exchange spider, why is it considered as reverse voting up again?  It feels like a spider, because I got nine upvotes in one minute. So why then is it considered as serial upvoting from the system itself if it's the system who is doing this spidering?  I wish I'm not wrong :)

Due to some "recent issues", I think the following is necessary:  Users need a way to contact moderators through the StackOverflow website.  This is especially important for suspensions, where there is no way to appeal or discuss the suspension from within SO itself.  Basically, there would be some kind of a box on the user's page that allows them to mention something to the moderators and some way to read the replies. (Or they could just go to the user's email.)


In Episode IV, everyone seems to believe that Vader is the only one left who can use the Force.     Tarkin: The Jedi are extinct. Their fire has gone out of the universe. You, my friend, are all that's left of their religion.   Of course, they thought the Jedi were all killed, but what about the Emperor?  I realize that he is not even mentioned in Episode IV, so did nobody know that he was a Sith? Or is it just the fact that he was not intended to be brought up in the movie at that point?

Anakin Skywalker was known as Darth Vader (this was already his Sith name) after the creation of the Galactic Empire.  So why did Palpatine remain "Emperor Palpatine"? Why didn't he embrace his persona as Darth Sidious?  I started wondering after reading one of the answers to


while (listItemEnumerator.moveNext()) {     var oListItem = listItemEnumerator.get_current();     listTitle.push(oListItem.get_item('Title'));     listUrl.push(oListItem.get_item('PrivacyStatementUrls').get_url());      listIsActive.push(oListItem.get_item('IsActive'));     listOrder.push(oListItem.get_item('SortOrder'));  } sessionStorage.setItem('Title', listTitle); sessionStorage.setItem('Url', listUrl); sessionStorage.setItem('IsActive', listIsActive); sessionStorage.setItem('Order', listOrder);   Here is my code for adding an array to sessionstorage. When outputting the array from session storage it seems to output a letter at a time but when I output the array without session storage it outputs the whole valu

SP.SOD.executeFunc('sp.js', 'SP.ClientContext', sharePointReady); var listTitle = []; var listUrl = []; var listIsActive = []; var listOrder = [];  function sharePointReady(){ var siteUrl = mysite;     var clientContext = new SP.ClientContext(siteUrl); var oList = clientContext.get_web().get_lists().getByTitle('Privacy Statements');  var camlQuery = new SP.CamlQuery(); camlQuery.set_viewXml(''); this.collListItem = oList.getItems(camlQuery);  clientContext.load(collListItem);  clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));         }    function onQuerySucceeded(sender, args) {  var listItemEnumerator = collListItem.getEnumerator();   while (listItemEnumerator.moveNext()) {     var oListItem = listItemEnumerator.get_current();     listTitle.push(oListItem.get_item('Title'));     listUrl.push(oListItem.get_item('PrivacyStatementUrls').get_url());      listIsActive.push(oListItem.get_item('IsActive'));     listOrder.push(oListItem.get_item('SortOrder'));    } sessionStorage.setItem('Title', JSON.stringify(listTitle)); sessionStorage.setItem('Url', JSON.stringify(listUrl)); sessionStorage.setItem('IsActive', JSON.stringify(listIsActive)); sessionStorage.setItem('Order', JSON.stringify(listOrder)); var retrievedTitle = sessionStorage.getItem("Title"); var arTitle = JSON.parse(retrievedTitle); var retrievedUrl = sessionStorage.getItem("Url"); var arUrl = JSON.parse(retrievedUrl); var retrievedIsActive = sessionStorage.getItem("IsActive"); var arIsAct = JSON.parse(retrievedIsActive); var retrievedOrd = sessionStorage.getItem("Order"); var arOrd = JSON.parse(retrievedOrd);  var test = '' for(x=0; x<arTitle.length+1;x++) {      for(i=0; i<arTitle.length+1;i++)     {          if(arIsAct[i] == true){             if(arOrd[i] == x){                 test +=''+arTitle[i]+'
';             }            }      } }  document.getElementById('test').innerHTML = test; }  function onQueryFailed(sender, args) {  alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace()); }   I am trying to use caching with sessionstorage when getting items from a list, so it doesn't have to keep querying the list over and over again. It can just check with the sessionstorage and if its in the list there is no need to get the item but if its not in sessionstorage get the item from the list. I am not sure how to do this, my code above shows my attempt


When I run my simple Java browser, I try and visit a webpage such as  and it returns the NullPointerException error from my try catch code, how would I fix this?  Frame Class:  public class Frame extends JFrame {  public EditorPane pane; public URLBar urlbar;  public static void main(String[] args) throws Exception {      Frame frame = new Frame();  }  public Frame() throws Exception {     super("Java Browser v1.0");      JPanel mainPanel = new JPanel(new BorderLayout());     URLBar addressBar = new URLBar("Enter URL here!", pane);     EditorPane contentDisplay = new EditorPane(urlbar);      mainPanel.add(contentDisplay, BorderLayout.CENTER);     mainPanel.add(addressBar, BorderLayout.NORTH);      add(mainPanel);     setDefaultCloseOperation(EXIT_ON_CLOSE);     setSize(700, 400);     add(new JScrollPane(mainPanel));     setVisible(true); }  }   URLBar Class:  public class URLBar extends JTextField {  public EditorPane pane;  public URLBar(String text, EditorPane pane) {      super(text);       addActionListener(new ActionListener() {             public void actionPerformed(ActionEvent event) {                 loadContent(event.getActionCommand());             }         }      ); }  public void loadContent(String userInput) {     try     {         pane.setPage(userInput);         setText(userInput);     }     catch (Exception e)     {         System.out.println("A wild exception appeared! Type: " + e);     } }  }   EditorPane Class:  public class EditorPane extends JEditorPane {  public URLBar urlbar;  public EditorPane(URLBar urlbar) {      setEditable(false);     setVisible(true);     addHyperlinkListener(             new HyperlinkListener() {                 public void hyperlinkUpdate(HyperlinkEvent event) {                         if(event.getEventType()==HyperlinkEvent.EventType.ACTIVATED) {                         urlbar.loadContent(event.getURL().toString());                     }                 }             }     );  }  }

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 am trying to build a complex number calculator in python. The number will be represented by a class with two fields. The first constructor I want to use looks like this:  def __init__(self,real,imag):     self.real = real     self.imag = imag   but i would like to use another, where the only parameter will be a string representing the whole number:  def __init__(self,string_number):   How to implement the overload that allows to use different number of parameters? I am more used to C++, where such thing was easy. Thanks a lot!  EDIT: Question marked as duplicate:  I did not find any answer regarding different number of parameters. The error I get when trying to build a new instance of the class is about to few arguments.

Let's say I have a class that has a member called data which is a list.    I want to be able to initialize the class with, for example, a filename (which contains data to initialize the list) or with an actual list.  What's your technique for doing this?  Do you just check the type by looking at __class__?  Is there some trick I might be missing?  I'm used to C++ where overloading by argument type is easy.


This should be a simple thing, but everywhere I've looked says what I have should work I think. After doing this for a few hours I'm calling it and asking for someone to point out the stupid mistake.  Here's my code:  \newenvironment{questions}[1]{ \stepcounter{QuestionGroup} } { \ifthenelse{\isempty{#1}}     {     0     }     {     #1     }{} }   When I try to compile this, it gives me the "Illegal parameter number in definition of \endquestions." And moreover it works just fine if I change all the #1 to some filler content, so it's not registering that the [1] should be an optional argument input.  So... what gives?

Environments are allowed to have arguments, but reference to those arguments can only appear in the opening code of the environment, and not the closing code.  What is the reason for this, and are there preferred ways around it?  e.g.  \newenvironment{foo}[1]% {some code #1} % allowed {some code #1} % not allowed


Is it possible to cast spells on places that can be seen through a familiar?  A wizard is inside a room and their familiar is outside of it. An enemy is also outside, in front of the familiar. Would the mage be able to cast, for example,  on that target?     You cause numbing frost to form on one creature that you can see within range [...]   on that target? I'm aware looking through your familiar is an action, but let's assume the wizard has multiclassed into a fighter and has Action Surge.

I had to make a call today and I'm wondering how this scenario should've gone down   The map was a U-shaped hallway; the party was on the lower left of the U, with the enemies on the upper right. The wizard has an owl familiar who could see an enemy caster, with the wizard seeing through the familiar's eyes, and the wizard was further back.   The enemy caster cast a fireball.  The player claims that since he was looking through the owl's eyes from his turn, he should technically have line of sight for a counterspell.   Could counterspell be cast in this case, even though there was a wall between him and the caster, and he was physically not able to cast towards the enemy caster?  Was I wrong in said judgement?


If an obstacle is removed, how fast does TFD move to catch up to its caster?     ...follows you so that it remains within 20 feet of you. (PHB 282)

Prior questions have established that the 5th Edition iteration of Tenser's Floating Disc , but  (or even exert horizontal force) when it does not have a legal path to a position within 20 feet of the caster. Therefore:  Suppose an enterprising wizard were to commission the construction of a structure on an empty field. The structure consists of a spiraling ten-foot-tall wooden wall or fence, with an outer radius of 100 feet, an inner radius of 20 feet, and a distance between each loop of 5 feet, thus creating a spiral corridor 5 feet wide and about 6000 feet long. A gate is placed at the outside opening of the spiral, and ladders and bridge over the structure allow the wizard to climb up and over the spiral to easily move from the outside to the inside.    The wizard, who  and therefore has not tested the following procedure at all, then offers any curious onlookers an exciting experience for a modest fee. The wizard casts Tenser's Floating Disk while outside the spiral and has the attendee seat themselves upon it. The wizard then climbs the ladder and traverses the bridge until they are in the center of the spiral structure. Then they signal to an assistant stationed outside the spiral wall, who opens the gate. At this point, the floating disk has a path to a space within 20 feet of the wizard which does not violate any of its movement constraints.  Does the disk move along the spiral path, and if so, how quickly?


What is the expected number of coin tosses it takes to observe tails followed by 2 consecutive heads, given that the coin is fair?   I have calculated the expected number of coin tosses for 2 consecutive heads (=6), is there a way to use this piece of information to calculate the above question? Or is there a way to tackle this question completely from scratch?

Inspired by Peter Donnelly's talk at , in which he discusses how long it would take for a certain pattern to appear in a series of coin tosses, I created the following script in R. Given two patterns 'hth' and 'htt', it calculates how long it takes (i.e. how many coin tosses) on average before you hit one of these patterns.  coin <- c('h','t')  hit <- function(seq) {     miss <- TRUE     fail <- 3     trp  <- sample(coin,3,replace=T)     while (miss) {         if (all(seq == trp)) {             miss <- FALSE         }         else {             trp <- c(trp[2],trp[3],sample(coin,1,T))             fail <- fail + 1         }     }     return(fail) }  n <- 5000 trials <- data.frame("hth"=rep(NA,n),"htt"=rep(NA,n))  hth <- c('h','t','h') htt <- c('h','t','t')  set.seed(4321) for (i in 1:n) {     trials[i,] <- c(hit(hth),hit(htt))     } summary(trials)   The summary statistics are as follows,        hth             htt          Min.   : 3.00   Min.   : 3.000    1st Qu.: 4.00   1st Qu.: 5.000    Median : 8.00   Median : 7.000    Mean   :10.08   Mean   : 8.014    3rd Qu.:13.00   3rd Qu.:10.000    Max.   :70.00   Max.   :42.000    In the talk it is explained that the average number of coin tosses would be different for the two patterns; as can be seen from my simulation. Despite watching the talk a few times I'm still not quite getting why this would be the case. I understand that 'hth' overlaps itself and intuitively I would think that you would hit 'hth' sooner than 'htt', but this is not the case. I would really appreciate it if someone could explain this to me.


I want to know how steam and other websites opens desktop application by web page  I find a similar example in microsoft support .  How does work?

How do I register a custom protocol with Windows so that when clicking a link in an email or on a web page my application is opened and the parameters from the URL are passed to it?


When I was a kid, more than 30 years ago, I remember watching a TV show at school in the UK. Would have been mid-to-late '80s. I think it was probably part of an English language thing, where they'd have worksheets for the kids to do after watching the show. In this TV show, there were aliens who masqueraded as humans. Sometimes they'd revert to their alien form and I think they were bald, and definitely had no noses. I remember the poor cast members were wearing prosthetics that blocked their ability to breathe normally, and ended up delivering their dialogue sounding terribly nasal. Any ideas?

I've been trying to track down a live-action children's TV series (or short story perhaps) from the 1980s or 1990s, probably on CBBC or CITV.  A few people I've spoken to IRL have suggested The Boy from Space or Sky, but I'm pretty sure it's neither as a lot of the details don't seem to match.  The story was set on Earth (possibly England or Wales) and was about an "alien" boy who was being pursued by a group of people, though I don't remember who they were.  Somehow he encountered siblings, a girl and a boy, and made friends with them. I think they lived on a farm with their parents, as I remember quite a large barn or other building, and they hid(?) the boy in a car which was inside or next to this building. He also slept in this car with a dog (which might have been a German shepherd).  The "alien" boy had a portable "radio" (all silver, very 1980s) that repelled his pursuers by emitting a high-pitched sound when he turned a dial on it, and he used it when out and about with the other children whenever they encountered a pursuer. I seem to remember lots of hills and valleys, lots of green.  In the end it turned out he wasn’t really an alien, but a human from the far future. He was pretending to be an alien as he was from 20000 years into the future and humans' appearance had changed by then, but he had the ability to make himself look like current-day humans. When he was in his car/bed he reverted to his normal appearance, so he would hide under the blankets until he was able to assume current-day human appearance.  In the finale, it was revealed that he was never in any danger – the pursuers were testing him as part of a kind of coming-of-age thing. I remember a scene on a spaceship or something where his elders/parents where shown telling him that he was safe all along and that he "passed".  I also seem to remember them referring to "ancestors" and making sure they didn't find out, so the either the girl or boy could well have been a direct ancestor.


I know this was covered elsewhere but my use case is causing me difficulty.  What if a string has a dreaded "\3" character like this one:  new_data = r'C:\temp\3_times.csv'   ...then re "thinks" that you're referring to it as a group so if you try to do a sub using that data then you get this error:  newfiledata = re.sub(old_data,new_data,filedata)  error: invalid group reference   Is there any way to avoid this error without looking for that case in the string and modifying it directly before passing it which would take lots of extra code.  Note: For the usage I'm going for modifying the string with escape characters isn't an option because I need to write the string with the sub function later on. So this is not a duplicate of the question on how to escape special characters.

I want to use input from a user as a regex pattern for a search over some text.  It works, but how I can handle cases where user puts characters that have meaning in regex? For example, the user wants to search for Word (s): regex engine will take the (s) as a group.  I want it to treat it like a string "(s)" .  I can run replace on user input and replace the ( with \( and the ) with \) but the problem is I will need to do replace for every possible regex symbol. Do you know some better way ?


I'm writing a technical report and I would like to include some graphics. Of course I could do them in TikZ but I don't know it and thus it is very time consuming. Another option would be to do it with Inkscape but the disadvantage is that it does not adapt to the LaTeX document (font size etc.).  Is there an editor which allows creating graphics by just drag & drop (like Microsoft Paint) and which produces TikZ output in high quality? The platform used is Windows 10, 64-bit.

After mentioning TikZ in , I tried to have a look here for recommended editors for TikZ. I found no list, and thus here's the question:  What TikZ editors/front-ends do you know? What can you recommend?  I guess that what I have in mind is a tool where the image can be edited using an interface similar to , and then it will generate a code snippet in TikZ. For example I know of , but I'm interested in a big list.  I am aware of the list available , as pointed by one of the answers to this , but I'm interested in some evaluation of each based on personal experience.  I suggest that each tool should has its own answer, this way this will become sort of a poll as well. Probably, each answer should contain at least: pros/cons/platform...


I am following a tutorial and it says to do: var original_UpdateInWater = typeof(Player).GetMethod("UpdateInWater"); var postfix_noSwim = typeof(Myclass).GetMethod("Patch_UpdateInWater");  Line 2 works, but line 1 returns null. Here is the referenced method. public class Player : Being, ISaveLoad, IInputsReceiver, IPeerWorldRepresentation {private void UpdateInWater()}  It seems to pick up the Player class correctly, unless their is a second class with the same name it is getting, but fails when it tries to get the method. What is going on? Is their some other method of getting the MethodInfo?

There are a group of private methods in my class, and I need to call one dynamically based on an input value. Both the invoking code and the target methods are in the same instance. The code looks like this:  MethodInfo dynMethod = this.GetType().GetMethod("Draw_" + itemType); dynMethod.Invoke(this, new object[] { methodParams });   In this case, GetMethod() will not return private methods. What BindingFlags do I need to supply to GetMethod() so that it can locate private methods?


I want to make an array of size 150 of the class Info  public class Info {     int Group;     String Name; }   But I have the exception occur after   public class Mover {         static Info[] info=new Info[150];             public static void main(String[] args) {             info[0].Group=2;//I get error here         } }   I'm not sure if there is a better way to do what a want to do, but I don't want to use a multidimensional array. I'm simply trying to add information to the group, so I'm confused.

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?


When I flag a post, there are two very similar options in the off-topic list.   I am running version 1.0.57 of the Android app; Android version 4.1.2 (Jellybean).  Is this supposed to happen? If so, what is the difference between them?

In the Android app, when flagging a question as off-topic, a generic option appears in the list of off-topic reasons, at the next-to-last position before migration or at the last position if migration is impossible. The formulation of this option is “This question does not appear to be about $TOPIC within the scope defined in the help center”.  That's not bad, but the website has different wording: “Blatantly off-topic (this question has nothing to do with $TOPIC)”. The app should use the same wording as the website.  Example:   vs