Food safety of cooked Lasagna that has been left on a counter and uncovered for 18 hours. What is the proper amount of time it can be left out of frig, and safe to eat as a leftover the next day.

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


I have this command line that I type in cmd all the time and I want to automate it as a .bat file E:\Programas\Steam\steamapps\common\Victoria 2>v2game -mod=mod/NameMod.mod  I tried several variations of this: echo off start "E:\Programas\Steam\steamapps\common\Victoria 2\v2game.exe -mod=mod/NameMod.mod"  But either I can't open the program or it doesn't load the tag that I want in the end. I'd appreciate it if you tell me what's the correct synthaxis. Thanks!

I have a Virtual Machine in Virtual PC 2007.  To start it from the desktop, I have the following command in a batch file:  "c:\program files\Microsoft Virtual PC\Virtual PC.exe" -pc "MY-PC" -launch   But that leaves a dos prompt on the host machine until the virtual machine shuts down, and I exit out of the Virtual PC console.  That's annoying.  So I changed my command to use the START command, instead:  start "c:\program files\Microsoft Virtual PC\Virtual PC.exe" -pc MY-PC -launch   But it chokes on the parameters passed into Virtual PC.  START /? indicates that parameters do indeed go in that location.  Has anyone used START to launch a program with multiple command-line arguments?


Find $S$ if $S=\tan^21^\circ+\tan^23^\circ+\tan^25^\circ+\dots+\tan^289^\circ$.   I tried converting all tangents above $45^\circ$ to cotangents and added them with tangents with the same angle, but that does not give any result nor does it telescope. Tried writing $\tan^2\theta = 1-\frac{\tan\theta}{\tan2\theta}$, but again, no headway. I am trying to relate this problem with complex numbers, and saying roots of a polynomial are of the form $\tan[(2n+1)\frac{\pi}{180}]$, but haven't been able to do so.

As the title suggests, I'm trying to find the sum $$\tan^21^\circ+\tan^2 2^\circ+\cdots+\tan^2 89^\circ$$ I'm looking for a solution that doesn't involve complex numbers, or any other advanced branch in maths. The solution can involve techniques such as induction, telecoping, etc, but preferably only ideas from precalculus, e.g. trig identities, polynomials, etc.  EDIT: I know that the sum is a rational number.


I read this short story from an anthology years ago, so I don't remember much of the details. It may have been written in the 50s to 60s.  It involves a man who has to visit a space station or an outpost in space, is exposed to alien writing and gradually ends up being unable to read his own written language. However, he is then able to read the alien writing.  Edit: There are probably more important details I'm missing here. This seems to have taken place in a small outpost/station in space, in a smaller enclosed space.

Short story read in the 60's or 70's, an astronaut has to enter an alien ship and collect the tears/sweat? of an alien to use as a wonder drug for humans. The alien has some sort of presence which affects the mental state of any human near it.


So, from I can tell from the answers I received to my previous questions, if I want to lower the output current from a battery, I could put a resistor in series with my circuit.   But wouldn't that only lower the current by some amount? If the battery output was lower than expected, it would be reduced farther by the resistor. And a greater than expected output would still be higher than the target current?  Another possibility is that I am hopelessly confused by all this, and should go find a nice book on EE.  edit: I should have said that the circuit I am trying to make, requires a fairly steady current flow, with a maximum current and a minimum current. (The minimum current is not super important, but it can't exceed the maximum current.)  edit: I should probably give a few more details. My coil/s should have 0.97232Ω of resistance, should use about 7.263 meters of wire.  edit: Could I use a current mirror?     With the reference current set to what I need my battery output to be?

I am currently working on a project that uses a 9.8V 1000mAh battery to power a solenoid, and as I understand it (please correct me if I got this wrong.) a battery capable of delivering 1000mAh is also capable of delivering 1Ah, or 2A for 1/2 hour, 4A for 1/4 hour, etc.  So, assuming I got the above correct, I need to know how to limit the battery output current to 1.0A (My circuit would get really hot otherwise.)


When I log in to stack apps to post a question via some website (gmail or facebook),after that it shows logged in so I have to click "log out" from its meta,Can you put a delete option there on my stack apps profile made recently?

How can I delete my Stack Exchange account(s)? Also,  What happens to my content? Can I request it be deleted as well? What if I'm suspended, rate-limited, or banned from posting questions or answers? What will happen to my votes? Will other users be impacted? Why wasn't my account deleted immediately after the timer expiring? What will happen to my pending bounties and close, reopen, delete, or undelete votes? I want my account deleted on all Stack Exchange sites. How do I do this? Will my profile on chat be removed once I delete my site account?   For more information, see "" in the .


When I tyr to convert a String "95941634.164" to a float and print the same, it is printing as 9.5941632E7 but not as 95941634.164.  I tried following conversion methods Float.parseFloat() and Float.valueOf()  public static void main(String args[]) {     String s = "95941634.164" ;     Float f  = Float.valueOf(s);     System.out.println(f);     System.out.println(Float.parseFloat("95941634.164")); }   Actual: 9.5941632E7 expected 95941634.164

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


From what I understand, the obvious problems with a gravity being a posed as a gauge theory of the Lorentz group are the residual tetrad fields having no obvious gauge theoretic interpretation, as well as this group simply not being the full set of diffeomorphisms. Gauging the full Poincare group appears to not only consider the full set of spacetime isometries but also provides a description of the tetrad fields as gauge potentials for the translation symmetries in the group.   What are the remaining obstacles to a convincing gauge theory of gravity?

Currently, (classical) gravity (General Relativity) is NOT a gauge theory (at least in the sense of a Yang-Mills theory).   Why should "classical" gravity be some (non-trivial or "special" or extended) gauge theory? Should quantum gravity be a gauge theory?  Remark: There are some contradictory claims in the literature to this issue. To what extent gravity is "a gauge" theory?Obviously, GR is not a YM theory. So, why do some people say that gravity "IS" a gauge theory? I found this question relevant, e.g., then we handle GR in the Einstein-Cartan theory or any other theory beyond GR, like teleparallel theories or higher-derivative gravitational theories. So I think it could be useful to discuss the "gauge flavor" of gravity here.


I am working on modeling a Turkish mosque and having difficulties modeling this 'merging' of its tower as shown in the picture below:  Here, the cubic shape below the tower merges with the cylinder of the tower, with its middle part shrinking its width and turning into a cylinder as it goes up. I am trying to model the same in blender, however I don't know how to approach modeling this one. As an initial approach, I made a rough model of the below cubic part and upper cylinder part. I left the middle empty as I don't know how to model that connector part. I thought of selecting all the edges that interface each other and tried simply connecting them by pressing F key. But it only ended up creating two faces one below the cylinder and one above the cubic shape. How should I approach this problem?  Note: I have a blender version 2.83

Is it possible to make one side of a cylinder square while leaving the other alone? If so how would I go about it? I have a tree branch that I need to connect to a trunk. The number of edges on the cylindrical branch will not connect up with the square hole on my trunk...Any ideas?


I've been reading code produced by other developers on my team, they seem to favor using += for String concatenation, whereas I prefer using .concat() as it feels easier to read.  I'm trying to prepare an argument as to why using .concat() is better, and I'm wondering, is there any difference in efficiency between the two?  Which option "should" we be taking?  public class Stuff {      public static void main(String[] args) {          String hello = "hello ";         hello += "world";         System.out.println(hello);          String helloConcat = "hello ".concat("world");         System.out.println(helloConcat);     } }

Assuming String a and b:  a += b a = a.concat(b)   Under the hood, are they the same thing?  Here is concat decompiled as reference. I'd like to be able to decompile the + operator as well to see what that does.  public String concat(String s) {      int i = s.length();     if (i == 0) {         return this;     }     else {         char ac[] = new char[count + i];         getChars(0, count, ac, 0);         s.getChars(0, i, ac, count);         return new String(0, count + i, ac);     } }


I am looking for a function same  of mysql in T-SQL(SQL SERVER) or some functionality

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


I have searched but have not been able to find one

I'm new to trading. Based on what I read, trading CFD involves high risk because of leverage.   Is it possible to trade CFD stocks without leverage (in Etoro for example)?  If this is possible, then I would lose/gain only the percentage by which the stock goes down/up.  Thank you


As the title says.  The proof for the last part is as follows: 1/3 = 0.333 with infinitely repeating threes. Multiplying both sides by 3, we have 1 = 0.333 with infinitely repeating threes * 3 = 0.9 with infinitely repeating 9s.  Edit:  The application for this question is with limits. Consider a function f(x) such that it defined as y = 1 for all x in [1,3].  lim f(x) x -> 1^- = DNE, since f(1^-) is not defined. But is this equation not the same as lim f(x) -> 0.99999 with infinite 9s? Since 0.99999 with infinite 9s = 1, then lim f(x) -> 0.99999 = f(1) = 1.

I'm told by smart people that $$0.999999999\ldots=1$$ and I believe them, but is there a proof that explains why this is?


I am going to be changing jobs soon and plan on visiting my girlfriend (in the US) later in the year.  Do I need to make any changes to my ESTA information or reapply since this information is used when making an ESTA application?

Last year I visited the USA the first time as a student.  Hence I filled in no previous employer and that I was a student.   Since then I graduated and got a job. My ESTA is still valid for my next trip, so I am wondering whether I can still use it?  Or should I get a new one to reflect that I am no longer a student?


I want to run a test in order to identify if there is any correlation between the length of in-hospital stay (Scale) and the kind of the procedure (Nominal with three options; abdominal, cardiac and other). Can you provide me with the right test from the Analyze menu in SPSS ?

I have a nominal variable (different topics of conversation, coded as topic0=0 etc) and a number of scale variables (DV) such as the length of a conversation.   How can I derive correlations between the nominal and scale variables?


I've just finished watching an episode of an american tv series. At the end of the episode, the narrator said, 'there is only two episodes left'. My question is: because two episodes is plural and countable, oughtn't it be 'there are only two episodes left'? I find this a bit of confusing, maybe because english isn't my first language, but until now, I thought that the language rules regarding this case aren't that complicated... Thanks!

Q: "Do you have any juice?"   A: "Yes, there's some in the fridge."   Sounds perfectly fine to me, but:     Q: "Do you have any towels?"   A: "Yes, there's some in the closet."   Does not.  I asked for towels - plural - so wouldn't "Yes, there're some in the closet," in which there are is turned into a contraction be the correct way to say it?  Spellcheck, however, doesn't like "there're", and I think I'm the only person I've ever heard use the word "there're".  Even folks who I know say "there are" shorten it to "there's" when possible.  Am I saying it wrong, or are both forms acceptable?


Assume I need to compare multiple sets and find which are equals or not.  In the end, I need to compare multiple sets and create a final set, with unique data taken from each set. Also I need to handle all items  which are repeating in different sets.

Does anyone know if there is a good equivalent to Java's Set collection in C#? I know that you can somewhat mimic a set using a Dictionary or a HashTable by populating but ignoring the values, but that's not a very elegant way.


I need to prove that given a graph G=(V,E), |V| = n and for any v in V with deg(v) at most k then  there are up to $2k+1$ disjoint stable sets (let's say $S_1$ ... $S_{2k+1}$) and their reunion is V.  Now, I suppose that in a coloring the vertices from a stable set could be the same color because the vertices are non-adjacent. And since the sets are disjoint we could say that each set needs a different color. So then the chromatic number of the original graph is $2k+1$ (or at least $2k+1$).   Now, I know that this is one way to look at the problem, but I have no idea how to connect that to the original hypothesis or how to start a demonstration from the hypothesis to the conclusion or from the conclusion to the hypothesis.   Thanks in advance!

I have a graph $G(V,E)$ where each vertex has degree at most $k$. How can I prove that I need at most $2k + 1$ disjoint sets of vertices in which there is no connection between two vertices from the same set to create the set of vertices $V$.


Suppose that $X$ and $Y$ are independent uniform $[0,1]$ random variables. Find the CDF $F(x)$ for the random variable $M = \max(X,Y)$ and find $E[M]$.  So $M$ will be uniform over $[0,1]$ and is the probability of $(0 < M < k)$ the probability that $(0 < X < k) + (0 < Y < k)$? I am not even sure if I should assume these variables are discrete or continuous..  Would the cumulative distribution function be:  $0$ when $M < 0$  $2M/1$ when $0 < M < 1$  $1$ when $M \geq 1$  and would $E[M]$ simply be $E[X] = E[Y] = 1/2$?  I have a feeling something is going over my head here. Is what I am doing correct?  Thank you!

I have a question. Let's suppose that the two random variables $X1$ and $X2$ follow two Uniform distributions that are independent but have different parameters:  $X1 \sim Uniform(l1, u1)$  $X2 \sim Uniform(l2,u2)$  If we define X3 as the maximum of X1, and X2, i.e., $X3 = max(X1, X2)$, what kind of distribution would it be? It is certainly not a uniform and I can calculate the cumulative probability, i.e., $p(X3 <= a)$, because $p(X3 <= a) = p(X1 <= a) p(X2 <= a)$. But, I wonder if there exists any density function that can model X3.


I recently installed Ubuntu alongside Windows 7 on my laptop (500 Gb hdd). In the partition step there were 3 partitions (recovery partition, hp tools, and the one I had Windows on it).   I selected on "new partition table", as a result I got one partition  (of 500 GB free space). Then I created a new partition (of 25000 GB,type: logical, ext4 journaling file system).   The installation went perfectly and Ubuntu is running perfectly.  However, when I reboot it goes to Ubuntu, and I can't find my Windows 7 option on the GRUB menu. Also, I can't find my recovery and Windows partitions. I don't have my Windows installation on a DVD, only the recovery partition.   I am afraid that my data on Windows are gone. Is there a way to boot to Windows without losing my data?

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


I exported a leaflet-webmap with qgis2web. On the top-left, there are the controls (like zooming, serching etc.). On the top-right, there is the layers control box (checking/unchecking the layers of the map). This is the one I want to change.  I want to move the layers control box to the left side, under the other control-box. When checking the source-code in my browser, the index.html shows a line <div class="leaflet-top leaflet-right"> - however, if I look to my saved index.html, there is no such line - it seems to be generated from somewhere else. But from where? I checked the files in css and js folders - found nothing. How can I change the position of this box?

This might be a silly question, but I could not find a documented way to achieve this.  I'd like to freely position the layer-control menu, probably to the top left near the default zoom-in/out button.  My layer control looks like this:  // Group layers as overlay pane overlayPane = {   "Endpoints" : endpointMarkerLayer,   "Links" : linkLineLayer };  // Add a layer control element to the map layerControl = L.control.layers(null, overlayPane); layerControl.addTo(map);   Where endpointMarkerLayer and linkLineLayer are layers containing markers and polylines respectively.  Is there an option to specify where the menu should appear? Or alternatively, how can I get a reference to the DOM-objcet of the control-menu, such that I could assign it a custom class and override positioning in CSS?


So it keeps giving me "java.lang.NullPointerException" whenever I user generic methods in my code.  I cant seem to find why it return null. Please any help :)  Console Trace:  java.lang.NullPointerException     at SignIn.FlockSignIn.windowTitle(FlockSignIn.java:41)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)   Generic Method:     package SignIn;  import java.util.List; import java.util.Set; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger;  import org.openqa.selenium.By; import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebElement; import org.openqa.selenium.support.ui.ExpectedConditions; import org.openqa.selenium.support.ui.WebDriverWait;  public class GenericMethods {     WebDriver driver;     private static final Logger log = LogManager.getLogger(GenericMethods.class.getName());      public GenericMethods(WebDriver driver){         this.driver = driver;     }       public void getTitle(){         String Title = driver.getTitle();         log.info("The title of the Page is: "+Title);         if(driver.getPageSource().contains(Title)){             log.info("The Title is Correct");         }         else{             log.error("The Title is InCorrect");         }     } }   Code:  package SignIn;  import org.testng.annotations.Test; import org.testng.annotations.BeforeClass; import org.testng.annotations.Parameters; import org.openqa.selenium.WebDriver; import org.openqa.selenium.chrome.ChromeDriver; import org.openqa.selenium.firefox.FirefoxDriver; import org.testng.annotations.AfterClass; import java.util.concurrent.TimeUnit; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import SignIn.GenericMethods;  public class FlockSignIn {     static WebDriver driver;     private static final Logger log = LogManager.getLogger(FlockSignIn.class.getName());     static String hydraURL = "http://google.com";     static GenericMethods gm;      @Parameters("browserType")     @BeforeClass     public void beforeClass(String browserType) {         if (browserType.equalsIgnoreCase("firefox")) {             System.getProperty("webdriver.gecko.driver",                     "C:\\Program Files (x86)\\geckodriver-v0.16.0-win64\\geckodriver.exe");             driver = new FirefoxDriver();         } else if (browserType.equalsIgnoreCase("chrome")) {             System.setProperty("webdriver.chrome.driver", "C:\\Automation\\chromedriver_win32\\chromedriver.exe");             driver = new ChromeDriver();         }          gm.maximize();         driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);         driver.get(hydraURL);         log.info("Opening the webclient");     }      @Test(priority = 0)     public void windowTitle(){         gm.getTitle();     }      @AfterClass     public void afterClass() throws InterruptedException {         Thread.sleep(10000);         driver.quit();     }  }

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 have a polygon layer with population and I need to create a new point layer based on that polygon layer.  The polygon layer has an attribute with the specific number of people living in each polygon.   How do I create X points (where X is the absolute number of people based on the attribute information) inside the boundaries of each polygon?

I'm trying to create a visual map in QGIS 2.4 of the approximate distribution of journey origin points using a shapefile of UK postcode sectors, layer joined to a table with a column giving the number of journey origins in each sector. Using the Vector > Research Tools > Random Points menu tool, I can select the Input boundary layer and click the 'Use value from input field' radio button, but the pull-down menu to select the required field does not seem to work. If I then specify the Output Shapefile name and target location , I get an error message - "Errors: The following features IDs couldn't be calculated due to conversion error: 335, 335". To confirm, QGIS does display random points if I specify the density or a specific number of points using the first two 'Stratified Sampling' Designs for individual polygs.


I just  that stars have metals in their cores that could theoretically be harvested by injecting enough mass to cause a supernova.  Say someone wanted to do this to our Sun.  How would you calculate (roughly) the amount of mass you would need to inject into the Sun to make it explode?

My understanding--though it's from a Science Channel show so I'm not sure if it is correct--is that there is a fusion reaction happening in the center of the sun. Atomic nuclei are being created and fused into higher atomic weights from lower atomic weights. By the time this reaction gets to iron on the periodic table (billions of years), the iron atoms are too heavy to allow the reaction to continue, so the star collapses and goes supernova within a short time.  Is this true? If so, can a comet made of iron enter the sun's core and destroy it? How much iron would it take? Or do I just have an inaccurate understanding (entirely possible).  Note: I do not intend to try to destroy the sun.


I understand subgradient is well defined for convex functions such as $f(x)=|x|$ but not for nonconvex functions. I don't have a good intuition how subgradient is defined for a nonconvex function. Can someone please provide a simple example that subgradient does exist for a nonconvex function? I tried to search but without success. Of course somebody have asked questions involving keywords nonconvex and subgradient, but that doesn't mean the same question.

In  (section 2.3), it is stated that:     A point $x^*$ is a minimizer of a function $f$ (not necessarily convex) if and only if $f$ is subdifferentiable at $x^*$ and $0 \in\partial f(x^*).$   Could anybody provide me with references for a proof of the above statement?   Is there a reference where we can learn more about subgradients of non-convex functions?  In Section 3. Calculus of subgradients of the above notes,many properties of subgradients are presented for convex functions. I would like to know which ones among these properties still hold for non-convex functions.  Thank you in advance!


At some point in my notes they essentially imply that when $u\sim \mathcal{U}(0, 1)$ then $-\log(u)\sim \text{ExponentialDistribution}(\lambda=1)$. Clearly this isn't true since by the integral transform we should use the inverse CDF?

For $X$ and $Y$ random variables; $X$ follows the uniform distribution.  (1): if $Y=-\log X$  (2): then it can be shown that $-\log X$ is distributed as $\exp(1)$ {i.e. exponential with mean 1}.  Why is this so? Intuitively statement (2) make sense to me. But i'd like a mathematical proof.  -Probably wrong working:  (1) seems to imply $\exp(-Y) = X$ (which is like saying $X$ is exponentially distributed, which is a contradiction, since its actually uniform!); or is it incorrect for me to do this since $X$ and $Y$ are random variables?  Ultimately how do I prove (2)?  Thanks


Can you please tell me what causes a page difference between the title/authors and the abstract?  \begin{document}  \title{\LARGE Spectral Clustering vs Wavelet Clustering: A Comparative Study}  \author{     \IEEEauthorblockN{M. Jalal\IEEEauthorrefmark{1}, R. Ramananda\IEEEauthorrefmark{1}}     \IEEEauthorblockA{\IEEEauthorrefmark{1}Electrical and Computer Engineering Department,%                                            University of Wisconsin-Madison%     \\\{jalal, ramananda\}@wisc.edu}      } \maketitle \pagestyle{empty} \thispagestyle{empty}   %**************************************************************************** % Abstract %**************************************************************************** \onecolumn \section{Abstract}

I don't know why each section is shown in one separate page when I use \onecolumn rather that the normal (two columns) format.  \onecolumn \section{Goals}  some text


There are too many (similar) stackexchange sites! Reasons why this is bad:  Waste of resources (it would be easier to manage and maintain to have fewer) Difficult to choose which one question is best suited for (, ). For a non-tech example, is  really a physics question or more about ?  There is a lot of overlap, for example there is , , and . Furthermore stackoverflow has tags that would make many of the questions on this site be suitable for it. Question may get migrated to a site you don't have an account for  () and may accumulate down and close votes. Smaller community base means fewer people are reading the questions and as such the chance of quality answers goes down Diffusion of responsibility () Sometime questions may be asked with the hope of getting different perspectives and since posting the same question to multiple stackexchange sites is not allowed, this could be a problem. Say for example you want to design something that is user friendly and secure. Different answers we be given on  vs  problems with migration, such as rejected migrations. more difficult to search for questions/answers. Now each possible site must be checked to see if the question was asked. (for example you wouldn't normally think to check both  and  for the same question)  I'm not saying there should only be one site, I am saying there should be fewer and beta sites shouldn't be created so liberally and that the boundaries between sites should be more clearly defined. I've heard a counter argument to this is that subsites were created as a response to new rules being made giving a smaller scope to Stack Overflow. This is not properly addressing the issues, those rules should be changed. Another example is, if someone is trying to setup and IDE on a Mac, should it go on super user, apple exchange, stackoverflow or programmers? It may not be known to the individual if the problem is specific to Mac or the IDE in general. Furthermore, we're now starting to .

I was just thinking that maybe if we have more Stack Exchange websites then each person would be a member of more different sites on average. Since the time a person can spend online on average is limited it means he will be spending less time on each website. But would this affect the quality of these websites? I'm not talking only about the quality answers given but also the number of answers given, the promptness. Won't these things go down?  I think that the rate of questions won't go down much because you need to know what you need to know. However, the average time a person spends browsing through these websites (and chances upon a question he can answer) would decrease. So are we creating too many different Stack Exchange sites?


So.. I recently tried to install git-all but it gave me a git-daemon-run error. I read that it is suggested to install git-daemon-sysvinit instead. However, now I am unable to install or purge anything. I get the following output when I try   sudo apt-get install git-all git-daemon-sysvinit  Reading package lists... Done Building dependency tree        Reading state information... Done git-all is already the newest version (1:2.7.4-0ubuntu1). git-daemon-sysvinit is already the newest version (1:2.7.4-0ubuntu1). The following package was automatically installed and is no longer required:   fgetty Use 'sudo apt autoremove' to remove it. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] y Setting up git-daemon-sysvinit (1:2.7.4-0ubuntu1) ... Failed to start git-daemon.service: Unit git-daemon.service not found. invoke-rc.d: initscript git-daemon, action "start" failed. dpkg: error processing package git-daemon-sysvinit (--configure):  subprocess installed post-installation script returned error exit status 5 Errors were encountered while processing:  git-daemon-sysvinit E: Sub-process /usr/bin/dpkg returned an error code (1)   I also get the same error if I try to uninstall or reinstall  git-daemon-sysvinit. So now I am basically stuck... I am running 16.04 LTS

I am using 15.04.   So I'm working with git and I installed the standard version. I set up the ssh keys and was able to clone one of my repositories to the correct folder. Everything was working great and then I decided it was a good idea to install more packages. I ran sudo apt-get install git-all. I'm looking at error codes now having to deal with upstart.  start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused No apport report written because the error message indicates its a followup error from a previous failure. dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   This is what happens when I even update/upgrade my system. At this point all I'm looking to do is be able to install software and update my current software. Is there any way I can potentially reverse this issue or at least correct it?   Edit: Thankfully this issue was solved only a day or two after it happened. The accepted answer worked perfectly and took care of my issue


I have a website of one of my clients that allows the user to delete pages by themselves with a form. When a page is deleted the website generates a 404 Error.  The deleted pages total about 5000, and the URLs deleted are still in the Sitemap submitted in the Search Console.   Are these 5000 404 Errors a problem? Should I use a 301 redirect pointing to a page with the message, "This page has been deleted"? Do I have to delete these deleted URLs from the sitemap?

Do the search engines take the number of 404 errors returned by a site into account when calculating the site rank? For example I have 8,000 404 errors and I am thinking that that's affecting my SEO in a negative way.  However, I read  about 404 errors which suggests that they are not always a negative quality indicator.   So I am confused...are high numbers of 404 errors harmful to a site or not?


There's a specific book I have been trying to remember/find for about 15 years, but any book in the same "category" is a welcome answer.  The specific book I'm trying to find involves a bunch of kids playing a role-playing game, with incredibly detailed figurines. They get pulled into the world of the role playing game, where they have to fight an villain who looks just like the Uncle of one of the kids playing the game. I believe the "main" character's avatar used a whip as his primary weapon.

The details I can remember are:    The trope of a role-playing group getting sucked into a different realm, possibly becoming their characters. One of the females becomes graceful, has the power to fly like a moth, possibly something about bracelets as part of her abilities(?). In one scene she might get stuck in a huge spider web.  One of the males is a scrawny guy but becomes a muscle-bound oaf in the realm they travel to.  They do get back to their own Earth realm, to the gaming table, but everyone was pretty bummed because they no longer had their alternate abilities/bodies.  It seems to have been some "journey to adulthood" type theme overall.    This was a book that was in my high school library in the 90's, was possibly published in the 80's or earlier.  I've searched for a bit, but have not found any books that fit what I remember.


I just started working with GIS very recently.  I'm trying to create a buffer of 200m around the points of the layer "vlaamse venen naamloze laag". But in the distance box, the program will only allow me to create a buffer in degrees? I checked the project properties, but they are in meters.     I tried using this question, () but I can't figure it out.  Changing the CRS of the layers makes that the distance is put in meters but then i have a different problem. If I change them (e.g. to Lambert 72 or Lambert 2008), my layers dont overlap anymore, which they should.

I'm very new to the GIS world, so my problem could be very stupid, but I'm going to try anyway.  Objective  Given a list of coordinates in longitude/latitude, stored as a .csv file, I want to create a buffer with distance of x km around those coordinates. (In case this is relevant, these coordinates are locations of the societies in the . These societies scatter all around the world.)  Problem  I'm only able to create buffers with distance in radial degrees, but I want to do them in (kilo)meters. I'm aware of the following Q&A's, but following what's suggested therein doesn't seem to solve my problem:          What I have tried...   I start QGIS (v2.4), and Add delimited text layer  choose my .csv file and the x/y fields, click OK select WGS 84 as my CRS (also tried NAD83 but didn't make a difference), click OK right-click on layer and select Save As..., in the dialog box, choose the following and click OK:  add sccs_meter.shp as layer to the current project Select Vector > Geoprocessing Tools > Buffers > set buffer distance as 10   The result is a buffer with radius of approximately 1068km, which suggests that buffer distance is 10 degrees rather than 10 meters.  What did I do wrong here?


When I startup mysql on my unbuntu server I will get a message.  121122 17:39:37 [Note] Plugin 'FEDERATED' is disabled. 121122 17:39:37 InnoDB: The InnoDB memory heap is disabled 121122 17:39:37 InnoDB: Mutexes and rw_locks use GCC atomic builtins 121122 17:39:37 InnoDB: Compressed tables use zlib 1.2.3.4 121122 17:39:37 InnoDB: Initializing buffer pool, size = 128.0M InnoDB: mmap(137363456 bytes) failed; errno 12 121122 17:39:37 InnoDB: Completed initialization of buffer pool 121122 17:39:37 InnoDB: Fatal error: cannot allocate memory for the buffer pool 121122 17:39:37 [ERROR] Plugin 'InnoDB' init function returned error. 121122 17:39:37 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 121122 17:39:37 [ERROR] Unknown/unsupported storage engine: InnoDB 121122 17:39:37 [ERROR] Aborting  121122 17:39:37 [Note] mysqld: Shutdown complete   a few times I have got a message saying that the plugin is disabled.  I use webmin to configure it. Could that be a problem?

I have been searching for a solution but nothing seems to work.  I have a single Drupal 6 website up on this server.    Server:Ubuntu 12.04 Apache/2.2.22 (Ubuntu) 5.3.10-1ubuntu3.8 MySQL 5.5.32 Drupal 6  Here is a link to my Apache2 and MySQL error files and my config file for MySQL.  Please have a look.  Those files are huge, that is why I linked to them instead of pasted them in here.  If I need to I can paste in here.  Just let me know.  Thanks.  I have done a lot of searching.  I mostly try to Google the errors themselves but can't seem to find the right solution.  I think I have narrowed it down to a problem with innodb but that is it.  I check the tables in the error log and phpMyAdmin say they are ok and I repair them anyway and still get the crashing.  When my site crashes, I have to restart Apache and then restart MySQL and then the site comes back up.  It has been crashing 2 - 6 times a day.  Any help would be greatly appreciated.  Thanks.


I found this  by the creator of PythonTeX himself. However, running the below code doesn't work for me; I get an error "Something's wrong--perhaps a missing \item. \end{pyblock}". I'm not convinced that the \pyc command is actually having the macro expanded. Where am I going wrong? I'm trying to use package keyval to provide a nice interface to some TeX commands which pass the values on to Python, but in order to do that I need to be able to expand the TeX macros which are the key-values so that Python may consume them. \documentclass{standalone} \usepackage{pythontex} \usepackage{lipsum}  \begin{document}     \pyc{mytext = """\lipsum[4]"""}          \begin{pyblock}     print(mytext)     \end{pyblock} \end{document}  I've created an even simpler example below. \documentclass{standalone} \usepackage{pythontex} \def\x{2} \begin{document}     \pyc{print(\x)} \end{document}  * PythonTeX stderr - error on line 8:     File "C:\Users\aosborne\AppData\Local\Temp\<outputdir>\py_default_default.py", line 50       print(\x)   SyntaxError: unexpected character after line continuation character

I am writing out some parameters to JSON files using pythontex, but would like to add context information in form of section numbers (for example \thesection or \thesubsubsection, perhaps also the page number or other counters).  Is there a straightforward way to pass the values of the section counters to Python?   Josef


Could someone help me as I am stuck with coming up with a proof for this?   Assume n is the total number of people in a town. Assume k is the number of possible ways to select a chief of the town. So the RHS is saying that there are k ways to choose a chief from n people.  on the LHS, From $i=k$, and $k=n$, it is referring to from k to n, which is the sum of the remaining people in the town who were not selected $(n-k)$, that there is $k-1$ ways to choose from $i-1$ objects. Since $i=k$, i could be the number of ways to possibly select a chief. If one person is chosen from i, who also belongs to $k, k-1$. But how does this lead to $${n \choose k}$$?

Can someone check my logic here.   Question: How many ways are there to choose a an $k$ person committee from a group of $n$ people?   Answer 1: there are ${n \choose k}$ ways.   Answer 2: condition on eligibility. Assume the creator of the committee is already in the committee. This leaves us with choosing $k - 1$ people from a group of $n - 1$ potentially eligible people. If all remaining people are eligible, there are ${n - 1 \choose k - 1}$ possible committees, if there are $n - 2$ eligible people, there are ${n - 2 \choose k - 1}$ committees, if there are $n - 3$ eligible people, there are ${n - 3 \choose k - 1}$ committees,..., if there are $k - 1$ eligible people there are ${k - 1 \choose k - 1}$ committees. Therefore,$${n - 1 \choose k - 1} + {n - 2 \choose k - 1} + {n - 3 \choose k - 1} + \dots + {k - 1 \choose k - 1} = {n \choose k}$$.


php rookie here. as grids are popular right now, I wonder if this is even possible. I have three posts and have no idea how to get this working; this is my basic loop                      // WP_Query arguments                     $args = array ( 'posts_per_page' => 3, 'category__in' => array(4,5)                     );                      // The Query                     $querytest = new WP_Query( $args );                      // The Loop                     if ( $querytest->have_posts() ) {                         while ( $querytest->have_posts() ) {                         $querytest->the_post();                          // do something                         get_template_part( 'content', 'front', get_post_format());                          }                      } else {                     // no posts found                     }   html output should be something like this:

   is there any chance this might work somehow?? I tried counting posts, but all I get was errors or totally wrong html output.  thank you, A.

If I have a loop running from a category query like :  <?php $the_query = new WP_Query('cat=1&showposts=50&orderby=title&order=asc');?>
 <?php while ($the_query->have_posts()) : $the_query->the_post();?>
..
<?php wp_reset_query(); ?> <?php endwhile; ?>
   How would I create an if clause that breaks the list at a certain interval, and starts a new one. So for example at the 10th post, return a
 and start a new one
 at 11.  This is incorrect but to illustrate my objective:  <?php $count =0;     while($count <=50){         if ($count == 9){             echo "
<a href='<?php the_permalink(); ?>'>                       <?php the_title(); ?>

";             }          elseif ($count == 10){         echo "

<a href='<?php the_permalink(); ?>'>                           <?php the_title(); ?>
";         }         else {         echo "
<a href='<?php the_permalink(); ?>'><?php the_title(); ?>
";         }   What is the correct way to include this logic into the loop?


How can I turn-off my laptop screen immediately if I want to?  Laptop: Lenovo Thinkpad  (Dual Boot) OS1: Linux Mint 17 OS2: Windows 8  I know there is power management, but it is not immediately. Need to set a time, and for Linux, the shortest is 5 minutes.  Is there any add-ons/extensions or software that can be downloaded so if I press a key, the screen will be turned off immediately?

Is there a way to turn off the display in Windows (7), preferably without using additional software?   Powershell script works fine, but leaves command-line window after turning on the display.


What kind of dragon slayer magic did Acnologia use to slay 10,000 dragon 400 years in the past?

Okay so all the other dragon slayers have an obvious element to their magic. Even with Acnologia's roar on Tenrou Island, there was no direct element to his magic. The only thing I could think of is just that his name is "The dragon of the apocolypse". So do we know what it is yet or not?


How can I write letter d with hyphen in the image file?

In math mode one can do $\hbar$, which produces an h with a little line through the top of it. I want to do the same thing, except with the letter d instead. Is there a generalization of $\hbar$ that works for other letters besides just h?


I use the \acrfull \acrshort commands. Sometimes I also used them in the \section, \subsection etc. commands. Now I get the warning:   Token not allowed in a PDF string (Unicode):(hyperref) removing '\acrfull'  Is it possible to get rid of this message and that the correct string is shown in the pdf?

When compiling a beamer presentation and using the following \author command  \author{Name \\ \texttt{my.email@domain.com}}   I get the following hyperref warning in my logfile  Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `\\' on input line 15.   Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `\new@ifnextchar' on input line 15.   I understand that this has to do with hyperref setting the PDF metadata, where the linebreak does’t make much sense and should be removed.  Trying to set  \hypersetup{pdfauthor={Name}}   does’t change the situation, seems like hyperref is still looking at the author command.  How do I get the desired display of author name with email and still keep hyperref happy?


I have posted one question on this website. While editing it, after scrolling down, I found this:  .   Kindly change it.

When I can scroll down far enough to have the hot network questions overlap the footer (because my question is short) there is no background under the text:    Could they either be given a white background: (just disable the transparency option)    Or stop at the footer:      This also happens with the help text on some sites, as per this bug report:     Ubuntu 14.04.1 (Latest LTS Version), . Same problem with  and .  Windows 10 Pro,  and .  (Images linked to screenshot of browser)  My question is different from  because my issue is the lack of background on the footer.   I think there was a site redesign?


I would like to create a two column table. On the left, I put the French text and the right for the English translation. But I have a problem that the text on each column is very long. Is there a simple way to change page automatically instead of manually inserting //?    \begin{tabular}{p{.50\textwidth}|p{.50\textwidth}}   \hline 1. Il y a plus de 50 ans que l'ingénieur Heaviside introduisit  ses règles de calcul symbolique, dans un mémoire audacieux où des calculs mathématiques fort peu justifiés sont utilisés pour la solution de problèmes de physique. Ce calcul symbolique, ou opérationnel, n'a cessé de se développer depuis, et sert de base aux études théoriques des électriciens. Les ingénieurs l'utilisent systématiquement, chacun avec sa conception personnelle, avec la conscience plus ou moins tranquille; c'est devenu une technique « qui n'est pas rigoureuse mais qui réussit bien ». Depuis l'introduction par Dirac de la fameuse fonction $\delta(x)$, qui serait nulle partout sauf pour $x=0$ et serait infinie pour $x=0$ de telle sorte que $\displaystyle{\int_{-\infty}^{+\infty}}\delta(x)\ dx=+1$, les formules du calcul symbolique sont devenues encore plus inacceptables pour la rigueur des mathématiciens. Ecrire que la fonction d'Heaviside $Y(x)$ égale à o pour $x<0$ et à 1 pour $x\geq 0$ a pour dérivée la fonction de Dirac $\delta(x)$ dont la définition même est mathématiquement contradictoire, et parler des dérivées $\delta'(x), \delta'(x)$, ... de cette fonction dénuée d'existence réelle, c'est dépasser les limites qui nous sont permises. Comment expliquer le succès de ces méthodes? Quand une telle situation contradictoire se présente, il est bien rare qu'il n'en résulte pas une théorie mathématique nouvelle qui justifie, sous une forme modifiée, le langage des physiciens ; il y a même là une source importante de progrès des mathématiques et de la physique. En fait de nombreuses justifications du calcul symbolique ont été réalisées ; les principales sont dues à Carson et van der Pol. Mais, si elles sont mathématiquement parfaitement rigoureuses, elles ne satisfont pas les physiciens, car ou bien elles passent par la transformation de Laplace, ce qui modifie complètement la question, ou bien elles éliminent la fonction $\delta$ et ses dérivées et interdisent des méthodes dont le succès était incontestable. &  %[English translation]  \end{tabular}  \end{center}

How do I make a bilingual (two-column) or trilingual (three-column) LaTeX document?  E.g.:   | Original language | Translation 1 | Translation 2 | |                   |               |               | |                   |               |               |   Also, paragraphs from each language must align vertically properly, too.  thanks


we say if distance between two charged bodies is large as compared to its size then we take them as point charges and assume all its charge content to be concentrated at one point in space. What is the location of that one point with respect to the original body? Is it always at the geometric centre of the body?

When determining the gravitational attraction between 2 solid bodies, we can simplify computations by taking their masses to be concentrated at their respective centres of mass. However, had they been electrically charged bodies and we needed to compute electrostatic attraction, there is no "centre of charge" notion available to us. ( We would evaluate a 2-dimensional integral, or equivalently, apply Gauss's law. )  Is there any simple reason for the absence of such a centre of charge? Frequently, I've got the answer: "charge just doesn't work that way".


Problem: I'm having trouble getting page numbers to display in a LaTeX document.  Background: I have a document with 0.3in margins that I suspect covers up the page numbers. A very similar document with 0.5in margins displays the page numbers. The preambles are identical except for the 0.2in difference. If it makes any difference, the document is built in R using the Sweave package. This is my most recent attempt:   \documentclass{article} \usepackage{setspace, relsize} \usepackage{moreverb}         \usepackage[pdftex]{lscape}     \usepackage{longtable}          \usepackage{url}                \usepackage[margin=.3in, landscape]{geometry}  \usepackage{hyperref} \usepackage{pdfpages} \usepackage{fancyhdr}  % New command to make R code stand out \newcommand{\co}[1]{\texttt{\smaller #1}}  \title{MIND-USA Site Report} \author{Screening, Exclusions and Enrollment} \date{\today} \pagestyle{fancy} \rfoot{\thepage} \begin{document} \SweaveOpts{concordance=TRUE}  \maketitle   What I've tried:   \pagestyle{plain}    This didn't do anything for the numbering, but the document compiled.   \usepackage{fancyhdr} \pagestyle{fancy} \rfoot{\thepage}    This also didn't do anything, but compiled.  I hope that provides the right amount of information and is an appropriate/helpful question!

I created a document in latex. The numbers of pages appears on pdf, but I printed the pdf and numbers don't appear.   Somebody can help me ?  Example of one of my pages:    my preamble code:  \documentclass[12pt,twoside,a4paper,openright]{report} \usepackage{color} \usepackage[portuguese]{babel} \usepackage[utf8]{inputenc} \usepackage[hidelinks]{hyperref} \usepackage[official]{eurosym} \usepackage{gensymb} \usepackage[lmargin=3.0cm,rmargin=2.0cm,tmargin=2.0cm,bmargin=2.0cm]{geometry} \usepackage{fancyhdr} \usepackage{graphicx} \graphicspath{  {fig/} } \usepackage{mathtools} \usepackage[round]{natbib} \usepackage{xr} \usepackage{siunitx} \usepackage{booktabs, multicol, multirow} \usepackage{pdflscape} \usepackage{emptypage} \usepackage{epstopdf} \usepackage{setspace} \usepackage{nomencl} \usepackage{tabularx} \usepackage{amsmath} \usepackage{booktabs} \usepackage{ragged2e} \usepackage{tikz} \usepackage{gensymb} \usepackage{chemformula}  \onehalfspace   \pagestyle{fancy} \fancyhead{} \fancyfoot{} \fancyfoot[RO,LE]{\thepage} \fancyhead[RO]{\slshape \rightmark} \fancyhead[LE]{\slshape \leftmark}  \begin{document} \pagenumbering{roman}  \tableofcontents \listoffigures \listoftables  \cleardoublepage \clearpage \pagenumbering{arabic}  \input{Intro}  \end{document}


i want startup a programm in a specific desktop with a .desktop config file  for example firefox on desktop 2

I would like to add a command at the rc.d system by which, when ubuntu starts it will run different program at different workspaces.I.e:workspace 1: chrome,workspace 2:thunderbird.How could this be achieved?Is there any tool?


I've always stumbled when looking at even simple circuits that use capacitors or inductors and trying to work out why it is there, without using "past experience".  What I mean is, if we need to limit the current we know that we need to use a resistor and we know how to work out which we need. If we need to reduce the voltage to something we again know we can use a resistor.  If we need to stop the flow of current in a specific direction we know that we need to use a diode.  All this can be worked out mathematically and "learnt" as circuits 101.  But I can't seem to find out information how to know when to use a capacitor, for example: We have X and Y and wasn't Z... "Oh so we need a capacitor here".  All the explanations for capacitors I've seen in circuits have been from peoples practical knowledge or past experience... without that, you wouldn't have known that you would have needed a capacitor.  My brother who's doing some electronics in school brought a simple circuit diagram home that they are making and yet there's a capacitor in it.  How do you work out and know that you need a capacitor without relying on past experience "I found if I stick in a capacitor it helps..." how do you learn or know when to use a capacitor from the start / design stage?

I'm a Trainee electrician and pc hardware enthusiast. I was just wondering why a mixture of inductors and capacitors are used on motherboards? Why not just use capacitor? I thought the inductor stores electrical charge but it uses magnetism. What's so special about storing it as magnetism?


I read this book probably 25 or more years ago. - Maybe 1988 or so. I keep thinking it was Heinlein (or really any classic sci-fi authors) but I haven't found it yet. I think it was a short book, not a huge novel. Maybe even a short story.   Here's what I remember...  Young boy lives on earth and uses a teleporter to go to school in a far away city. Each morning he uses it to get to school then uses it to come back after school. One day he has a test in one of his classes to see if he can survive on an alien planet (maybe, that part is fuzzy) so they use the teleporter (I think?) to transport him to an alien planet to survive. Maybe the transporter breaks and they can't get him back. Maybe. I can't remember if any classmates go with him or if he's alone and I can't really remember what happens on the planet.   I'd like to re-read it, if i can figure out what it is. That's all I remember.  Ideas?

I would love to identify a sci-fi novel I read in the late 60s or 70s.  It followed a group of young space cadets through their training in the Space Academy.  The training culminated in small groups of cadets being sent through a gateway in the space station, into different worlds where they had to survive whatever conditions they met beyond the gateway, as part of their training.  One such trip went wrong and the group ended up stranded in a hostile world for days, hoping to be rescued by their trainers.  I can't remember much about the story or protagonists so this may be too vague, but I remember descriptions of a vast space station hall and these young cadets bringing whatever kit they hoped they might need - some brought breathing apparatus and full survival gear, but others came with very little as they believed they would not be sent into conditions where they could die without the right equipment.  They hadn't bargained for the power surge or whatever it was that misdirected them as they passed through the gateway!  I also remember rivalry between the cadets - I think the hero was male and quietly heading for top cadet of the year award... and I think at least one of the group died in the unknown planet before they were rescued.  Does this ring a bell with anyone?  I remember the mood and tension more than the details but it was a long time ago!  I have a 10-year old son who I think would love this kind of story.  If anyone can help you have my thanks!


I remove and add a lot of controls dynamically to a form. How can I redraw the GUI only once?   After each removing or adding of a control it is redrawn.

During a complicated update I might prefer to display all the changes at once. I know there is a method that allows me to do this, but what is it?


I have some very basic knowledge regarding the working of intents. I am a user of Tasker. Even after a lot of searching, I could not find any intent using which I could send a WhatsApp message. But, as we all know, the Google app using some method to send WhatsApp messages when we say * Send a WhatsApp message to XYZ*. How does the Google app do this?

I'm trying to automatically change the text status (not the photo/video status) in WhatsApp via Tasker by sending an Intent. My problem is that I don't know if it's possible to call the status to change it, and if it is possible, how to do that.  Any help is appreciated!


I recently installed eclipse but its not starting when i enter command "eclipse" on terminal. I am pasting a log, Kindly review it and suggest solution to fix the problem

I want to install the latest version of Eclipse but the Ubuntu Software Centre contains an older version.  Is there a PPA or some other way to install latest Eclipse? Please describe the steps for full installation.


I am running chrome Version 77.0.3865.120 on macOS.  when chrome finished to load a page, it looks like this figure    when I try to select part of the URL, it becomes like this    It takes and wastes me another click/tap, which is boring and inefficient. Is there a way to force chrome keep showing or hiding the "https://" part?

A couple of days ago I noticed that for all websites, chrome omits from the address bar the protocol and the subdomain if it is www. My co-workers report that they are not seeing this. Chrome version is 67.0.3396.87.  For example, if I type into the address bar https://www.google.com (without the quotes), Chrome immediately displays the chip "Secure" followed by google.com. See attached screenshots.      I have looked in vain for Chrome settings that affect this, plus the chrome://flags page and chrome://net-internals page.  I did not do anything consciously to make this change.  Any ideas?  EDIT: Suggestion from MrWhite that Ominbox UI Hide Stead-State URL Scheme and Trivial Subdomains had become enabled: good suggestion, except that the setting is still at “Default.” See screenshot:    However, as a shot in the dark, I am going to play with the setting to see what happens.  First I set it to “Disabled.” That restored the previous behavior of the address bar, which is to not to hide the protocol and “trivial subdomains.” Then I changed it back to “Default,” and it was hiding them again. One would suspect that somehow the default has been changed, except that co-workers are not reporting this issue.  Oh, well. I’ll just leave it as Disabled for now.  I would be ready to accept the answer from MrWhite, because it provides a workaround. Yet will leave it open for a bit longer, because it does not really answer why this behavior has changed, and why it has to be overridden.  EDIT 2: Chrome version is 67.0.3396.87.


Question: Show that $$\color{Blue}{e^{-\pi/2}=i^{i}}$$  My answer: First establish that $\qquad\qquad\quad e^{-i\pi/2}=\cos(-\pi/2)+i \sin(-\pi/2)=-i$ then $\qquad\qquad\qquad\qquad \mathrm{Log}(e^{-i \pi/2})=\mathrm{Log}(-i)$ so $\qquad\qquad\qquad\qquad\quad -i \mathrm{Log}(e^{ -\pi/2})=\mathrm{Log}(-i)$ $\qquad\qquad\qquad\qquad\qquad\quad \mathrm{Log}(e^{ -\pi/2})=-i^{-1}\mathrm{Log}(-i)$    Therefore the RHS should equal to $\mathrm{Log}(i^{i})$, but how?

According to WolframAlpha,  but I don't know how I can prove it.


Assume $R$ is a ring, $\psi:M\rightarrow N$ a surjective $R$-modules homomorphism. Then, $M$ is noetherian $\iff$ $N$ and $K=\operatorname{Ker}(\psi)$ are noetherian.  So I proved $\leftarrow$. Now I assume $M$ is noetherian. It's not hard to show $N$ is noetherian since $\psi$ is surjective. Now I tried to prove that $K$ is noetherian - I took $K'\subseteq K$ a submodule of $K$. So, $K'\subseteq M$ and therefore it's a submodule in $M$ and so if finitely generated. Is my reasoning correct or am I missing something (maybe the fact that it's finitely generated in $M$ doesn't mean its finitely generated in $K$?). Any help would be appreciated.

Let $0 \to M' \xrightarrow{\alpha} M \xrightarrow{\beta} M'' \to 0$ be an exact sequence of $A$-modules. Then $M$ is Noetherian is equivalent to $M'$ and $M''$ are Noetherian.  For the ''$\Leftarrow$'' case:  I guess if we let $(L_n)_{n\geq 1}$ be an ascending chain of submodules of $M$, then $(\alpha ^{-1}(L_n))_{n\geq 1}$ is a chain in $M'$, and $(\beta(L_n))_{n\geq 1}$ is a chain in  $M''$. For large $n$ both these chains are stationary. Then why we know the chain $(L_n)$ is stationary?   Thanks!


When I try to put the picture at the top of the page, it moves to the next page. What should I do to make the picture at the top of the current page, and will not move to the next page?  I use this code:  \begin{figure*}[!t] % normal figure code  \end{figure*}    Thank You!

I know there is a command like   \begin{figure}[p] \end{figure}   But when I use it in a two-column model, the $[p]$ cannot work. So I am wondering if there is any solution to preserve the figure in current page when I use $\begin{figuire*}$.


I have created a table and want to get an id on a td click. The data is population through an ajax call and I an want an id on when delete is clicked. So its on the fly the elements are added.  $.ajax({         url: 'http://localhost:8080/getUsers,         type: 'GET',         success: function (data, textStatus, jqXHR) {             $.each(data, function (index, result) {                 $("

").attr("id",result.user_id+"userTr").appendTo("#userTBody");                 $("	").attr("id",result.user_id+"userName").appendTo("#"+result.user_id+"userTr");                 $("#"+result.user_id+"userName").html(result.username);                 $("	").attr("id",result.user_id).appendTo("#"+result.user_id+"userTr");                 $("#"+result.user_id).html('Delete');                 $("#"+result.user_id).css('cursor', 'pointer');                 $("#"+result.user_id).addClass("delete");             });         },         error: function() {             alert('err')         }     });  $('.delete').on('click', function () {         alert($(this).attr('id'));     });   I have also tried with this.id but nothing happens.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Given a matrix A, what do eigenvectors and eigenvalues of A imply? I know how to calculate them but I want to understand WHY do we need to find them? In what application this is important  Thank you

What is the importance of eigenvalues/eigenvectors?


Hello I am trying to auto refresh this div tag. It contains an iframe that links to an outside url for a widget. I would like it to refresh every 30 seconds. Just curious how this can be done.

     I am getting an uncaught exception error commented about below. This is for an external site that is linked in the iframe and there is no data being written locally to pull to update. The div simply needs to be refreshed.

I would like to reload an <iframe> using JavaScript. The best way I found until now was set the iframe’s src attribute to itself, but this isn’t very clean. Any ideas?


I've recently changed my Nvidia driver version & rebooted to        Black screen or    This is not a exact duplicate of  because    not installing nvidia drivers for the first time I have not installed or upgraded to Ubuntu 16.04: this question isn't specific to 16.04   Some of the answers are the same but the question is not an exact duplicate.   The justification for this post is the "inaccessibility" of the "duplicate" post to new users like in these examples:                        There are a lot of questions like these one. Just  for yourself, so let's make one good specific answer for the new guys.

I installed or upgraded to Ubuntu 16.04, but I'm having some problems with my graphics card.   The display is blank The display flickers Items on the screen do not display correctly Certain programs complain of graphics issues The computer boots to low-graphics mode Your specific issue may not be here, but try the solutions described in the answers anyway.   This question is very broad, but each one of these issues likely has one solution.    If you are experiencing a login loop, check the last part of my answer.    If you experience one of the listed issues and have your own solution (mine didn't work, or there's a faster way), feel free to post another POLITE answer, describing your problem and how you fixed it.    Those attempting to install Ubuntu, please refer to the section titled: If you are unable to enter a TTY or are trying to install Ubuntu.


In theory can entities in future spacetime look "back in time" to us, as we look back in time to other entities light years away, or is time simply a function of the distance and distance determines the relative time of all entities in relation to one another?

From my understanding of light, you are always looking into the past based on how much time it takes the light to reach you from what you are observing.  For example when you see a star burn out, if the star was 5 light years away then the star actually burnt out 5 years ago.  So I am 27 years old, if I was 27 light years away from Earth and had a telescope strong enough to view Earth, could I theoretically view myself being born?


For the following C++ code:    #include <iterator>  template<typename It> void dwim(It b) {     typename std::iterator_traits<It>::value_type currValue = *b; }   I can't understand why the typename is required here. Since for , shouldn't the compiler deduce the value_type is Iterator::value_type?

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


Problem: Find the centroid of the part of the large loop of the limacon $r=1+2\cos(\theta)$ that does not include the small loop.   I know that in order to compute the centroid one needs to use following equations $$x=\frac{\iint_D xdydx}{m}$$ and $$y=\frac{\iint_D ydydx}{m},$$ where $$m=\iint_D dydx.$$ Note that we are assuming $\rho=1,$ which should work for this problem since I got the correct answer for a similar problem. The real issue that I am facing is that I am unable to set up the bounds on the integral because I do not what values of $r,\theta$ do I have to exclude in order to avoid the loop. Any help in this regard would be much appreciated.


1/ Sometime you write       ALTER DATABASE [MyDb] COLLATE SQL_Latin1_General_CP1_CI_AS   after a moment, if you try        ALTER DATABASE [MyDb] COLLATE FRENCH_CI_AS   it may not succeed. why this?  2/ if table1 is SQL_Latin1_General_CP1_CI_AS and if table2 is FRENCH_CI_AS one cannot write ...where table1.field1= table2.field2  What is the consequence of COLLATE in a database or table ?

I can read the MySQL documentation and it's pretty clear. But, how does one decide which character set to use? On what data does collation have an effect?  I'm asking for an explanation of the two and how to choose them.


I have seen the files /usr/share/gnome-control-center/keybindings but in these file there are only names...  i.e.  <KeyListEntry name="move-to-workspace-1" description="Move window to workspace 1"></KeyList    Entry>   But how can I find out the key combination (like Ctrl+.....)?

I usually load a new version for every release to keep my OS fresh while preserving the last version on another partition as backup. I also employ a lot of custom key mappings.  I've figured out how to transfer the majority of my configuration across systems so far but I can't figure out where the custom keyboard shortcut mappings are stored.  Does anybody know where gnome puts these? Are there separate user config (i.e., ~/) and system config (i.e. /etc) files?


I am performing a renovation of my upstairs bathroom, which initially had carpet. After pulling up the carpet, I discovered vinyl flooring, which was adhered to a plywood subfloor. Although I was smartly wearing a p100 facemask style ventilator rated for mold and asbestos for most of the removal, I very stupidly pulled the vinyl flooring up in an attempt to prep the floor for a layer of thinset mortar for new ceramic tile. While it was not visible per se, I am certain this must have generated some kind of "dust" or particulate release, as I really tore up this backing, which stubbornly came off in non-uniform layers of varying sizes. I ultimately went to town on it with a scraper. In my research into the possibility of wallboard containing asbestos, I now know there is a likelihood that the vinyl backing also contained it. Terrified, I removed the material from the house, put my clothes in the wash, showered, and vacuumed the hallway outside of the bathroom. I am aware of the dangers of asbestos, and it has me positively shook. My question is, what should I do now? The clothes I used are in my washing machine, but it hasn't been run yet. With what I've learned, my plan was to remove these clothes and dispose of them in a plastic trash bag, then run the wash on empty to try and flush any trace fibers. All of the removed flooring was thrown through a second floor window and is in a pile next to my house - I planned to have that bagged and hauled away as well. Lastly, I was going to put the respirator back on and put the thinset mortar down as gently as I can (after wetting the remaining "stuck" backing) to seal the last of the fibers under the thinset - then tile as usual. Paranoid as I am, I wanted to ask for advice somewhere before I did anything. Do I need to test for it / call an abatement service immediately? The bathroom door was open while I removed the materials, and even when closed the door has a half inch clearance, could these fibers have (or could still be) contaminating my whole house? Thank you Concerned DIYer

A few years ago my parents did some work on an interior drywall in our house (built in 1987) [US]. Now I wonder if I might've been exposed to asbestos and I'm freaking out. On the bright side, I was never near the work area when the work was being performed. Given it's an interior drywall (the partition between kitchen and family room), probably there wasn't any insulation that could've contained asbestos. Given the research I did, it seems asbestos was far more commonly found in the joint compounds than the dry wall itself, and that asbestos was banned from joint compounds in 1977. I understand there's nothing I can do at this point. Just hope someone who knows more about this topic can give me an idea of my risk. I would send a sample to get tested except the housing is being rented now and my parents have moved to a newer house and I no longer live with them. Thanks


If a sentence starts with a mathematical variable which normally is lower case, should that variable be capitalized? Or is it better to just avoid starting sentences with variables?        x and y represent the width and height of the anticuboctahedron.   X and y represent the width and height of the anticuboctahedron.   The width and height of the anticuboctahedron are represented by x and y.

Possible Duplicate:          Let's say that you have a word that should be typed with leading lowercase letter. Perhaps it's a computer command. Perhaps it's an Internet nickname. I can't find any more serious examples.  When you put that word at the beginning of a sentence, should you capitalise it?     cat allows you to display contents   of a file.   The convention is that commands are typed in fixed-width font, so this doesn't stand out as much.     soccer_boy_89 turned out to be my   sister's account.   This does, though.  Of course you could paraphrase the sentence such that the problematic word is not the first one, but that's not the point here.


I am trying to prove the following statement:  If $f$ is integrable on $\mathbb{R}$ with respect to the Lebesgue measure $m$, the sequence $f(x+n) \to 0$ for $n \in \mathbb{N}$ as $n \to \infty$ for almost every $x \in [0,1]$  I know somewhere I have to use the fact that the Lebesgue integral is translation invariant, which I have proven. Now, my problem is to find something I can work with, but I am very lost.

I want to show that for $f: \mathbb{R} \rightarrow\mathbb{R}$ Lebesgue integrable  $\displaystyle{\lim_{n \to +\infty} f(x+n) =0}$ almost everywhere.  It is clear to me that this statement is true and I have tried to prove it by contradiction, by assuming that either $\displaystyle{\lim_{n \to +\infty} f(x+n) =\infty}$ or$\displaystyle{\lim_{n \to +\infty} f(x+n) =K}$ with $K\in \mathbb{R}$ .  In the first case  we can follow that $|f|=\infty$ so that $\int_\mathbb{R}f=\infty$ and we have a contradiction.  In the other case we know that there must be an $a\in \mathbb{R}$ so that $\forall x>a$ we have $f_+(x)>K/2$ and by that:  $\int_{{\mathbb{R}}+}|f|>\int_{\mathbb{R}_+}f_+=\int_{[0,a]}f_++ \int_{(a,\infty)}f_+>\int_{[0,a]}f_++\int_{(a,\infty)}K/2=\infty$  Would this be enough to show the statement? Can I even make the assumption that the limit of $f(x+n)$ "exists"? Any hints would be great.


I am new to R and to mixed linear modelling. I have a dataset with variables from a cross-sectional study looking at fractional anisotrophy (a property of the brains white matter) in 6 different white matter fibre tracts in the brain. For each fibre tract there are 2 measures (one from each hemispheres). There are 66 participants divided into two groups. We want to control the group comparisons for differences in age, the average FA volume across the brain (wholebrain FA) and tract volume.   I assume that Group (Patients/Controls), Tract (CB/SLF1/SLF2/SLF3/UF/OFST) and Hemisphere (Left/Right) are fixed effects and that Subject (n=66) is a random effect. I also assume that Age, Wholebrain FA and Tract volume should be modelled as fixed effects. For Age and Wholebrain FA there is one value for each participants, but for Volume there is one value for each observation. The attached picture presents the table in the long format. For each subject there is 12 observations.     We hypothesized that there would be group difference in each of the six fibre tracts. We had no a priori assumptions about the hemispheres but would like to explore this post-hoc. We would also like to explore associations between Age and FA in different tracts.  My suggested model look like this  mixed.lmer <- lmer(FA ~ Age + Wholebrain_FA + Volume + Group * Tract * Hemisphere +                       (1|Subjects), data = DTI)   Question 1: Given that Tract and Hemisphere are assumed to be fixed variables but also are within-subject variables, are they correctly modelled? I am having a hard time understanding how the model "understand" that these variables have multiple levels from the way its written above.  Question 2: The Volume variable is a within-subject variable whereas Age is a between subject variable. Should they then not be modelled differently?    Question 3: Whether or not to include a three-way interaction is a major debate in my research group. Some saying that for practical purposes its impossible to really make sense of it. Other say it can guide the decision of whether or not to test differences between groups for each hemisphere in each tract. Including a three way interaction to the model is likely to change the results significantly so it seems pretty important to get it right the first time. Any thought on this? Is it being a criminal to include it?

I am new to R and to mixed linear modelling. I have a dataset with variables from a cross-sectional study looking at fractional anisotrophy (a property of the brains white matter) in 6 different white matter fibre tracts in the brain. For each fibre tract there are 2 measures (one from each hemisphere). There are 66 participants divided into two groups. We want to control the group comparisons for differences in age, the average FA volume across the brain (wholebrain FA) and tract volume.  I assume that Group (Patients/Controls), Tract (CB/SLF1/SLF2/SLF3/UF/OFST) and Hemisphere (Left/Right) are fixed effects and that Subject (n=66) is a random effect. I also assume that Age, Wholebrain FA and Tract volume should be modelled as fixed effects. For Age and Wholebrain FA there is one value for each participant, but for Volume there is one value for each observation. The attached picture presents the table in the long format. For each subject there are 12 observations.    We hypothesized that there would be group difference in each of the six fibre tracts. We had no a priori assumptions about the hemispheres but would like to explore this post-hoc. We would also like to explore associations between Age and FA in different tracts.  My suggested model look like this  mixed.lmer <- lmer(FA ~ Age + Wholebrain_FA + Volume + GroupTractHemisphere + (1|Subjects), data = DTI)   Question 1: Given that Tract and Hemisphere are assumed to be fixed variables but also are within-subject variables, are they correctly modelled? I am having a hard time understanding how the model "understand" that these variables have multiple levels from the way it is written above.  Question 2: The Volume variable is a within-subject variable whereas Age is a between subject variable. Should they then not be modelled differently?  Question 3: Whether or not to include a three-way interaction is a major debate in my research group. Some saying that for practical purposes its impossible to really make sense of it. Other say it can guide the decision of whether or not to test differences between groups for each hemisphere in each tract. Including a three way interaction to the model is likely to change the results significantly so it seems pretty important to get it right the first time. Any thought on this? Is it being a criminal to include it?


In our 5e game, I was put on the spot for some loot the players were promised by a Hill Gnome. When it came time for their reward, I made up a dagger that can paralyze whatever it stabs, gave it to our Dragonborn Fighter, and it really threw off the balance of the game. It's all he ever uses anymore, and I need to find a way to get rid of it, because whenever something is resistant to paralysis, he gets mad saying I made it so that he can't do anything in the fight. Is there some way I can get rid of it in a fair way? Maybe a monster, or spell?

At one point my party cleric found a magic item that allowed him to pull anything smaller than the item out of it, like a Star Trek replicator. Now nothing is a challenge for him anymore. How would I make the item less powerful without just saying "your item is now less powerful" and breaking the immersion of the game by violating continuity?


Hope anyone can help explain the following behavior and how to fix it I have a DataFrame like this: l = [[1, 50, 3, 4.003], [1, 50, 4, 5.002], [2, 10, 3, 5.003], [2, 50, 2, 5.004]] df = pd.DataFrame(l, columns=["a", "b", "c","d"])  df # Output:     a   b   c   d 0   1   50  3   4.003 1   1   50  4   5.002 2   2   10  3   5.003 3   2   50  2   5.004  Now if I do a simple sum of column "d" row1 + row2 I should expect a result of 9.005, right? Well wrong, instead I get 9.004999999999999, this is what I do: sum = df.loc[0]["d"] + df.loc[1]["d"] sum # Output: 9.004999999999999  This affects the outcome of rounding to 2 decimal points after the sum. I did some research on the internet and it might have to do with number of bytes used on the float64 data type but is there a way to overcome this issue? By the way when I try the same with regular python variables it does the same thing: d0 = 4.003 d1 = 5.002  d0 + d1 # Output: 9.004999999999999  The challenge is that if I need to round the results to two decimals I want to get 9.01 and not 9.0 round((d0 + d1), 2) # Output: 9.0  # It should have been 9.01  So when we have thousands or even millions of records one would have to identify which values are having the point-precision error before summing and rounding to avoid this issue?, it will be very impractical, any other suggestions?

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


Let $f:X\times X \to [0,\infty)$ and   1) $f(x,y)=f(y,x)$   2) $f(x,y)=0 \Leftrightarrow x=y$  (Note that we remove the triangle inequality from the definition of a metric.) My question is why the triangle inequality is necessary in the definition of a metric? Why it is useful?

There is a property in the axiomatization of metric space: $d(x,z)\le d(x,y)+d(y,z)$. I understand that property applies well when it come to the measure of distances among points. However, that property seems to be irrelevant in the definitions of continuity, open set and some other key concepts.  My topology book says that it is asserting "the transitivity of closeness", a vague term that loses me. So why is that property important? Why did the founders (if any) of topology consider it at the first place? And what if that property is missed?


I've been using Google Openid for sometime to login to Stack Exchange network. Lately I started to work with another Google account on my PC. this causes Stack Exchange to try to login with the wrong Google account. I decided that I rather use Stack Exchange Openid to login instead.  Is there a way to port my Gmail openID user to Stack Exchange openID user?

I no longer use the service that I originally used to register, and would like to change the service I use to log in, or at least add a second account.  Is this possible? How do I change my login provider or associate a backup method to log in?     For more information, see "" in the .


Is it true to say that all matter in the universe is travelling with velocity c through spacetime, but that for baryonic matter most of that velocity is through the time dimensions rather than the XYZ axes?

I read that an object at rest has such a stupendous amount of energy, $E=mc^2$ because it's effectively in motion through space-time at the speed of light and it's traveling through the time dimension of space-time at 1 second per second as time goes forward.  What troubles me here, is the fact that it is traveling through space-time at the speed of light. Why is it at the speed of light?


WPF application has been started with email link and I have same application installed in system so once installed application opened and login in to application and after clicked on email link, it is opening another instance.  It may be open single instance of application. Please advise.  Thanks, Gaurang

Using C# and WPF under .NET (rather than  or console), what is the correct way to create an application that can only be run as a single instance?  I know it has something to do with some mythical thing called a mutex, rarely can I find someone that bothers to stop and explain what one of these are.  The code needs to also inform the already-running instance that the user tried to start a second one, and maybe also pass any command-line arguments if any existed.


For example, I want to refer to someone on the internet, but I don't know this person's gender. Which personal-pronoun do I use? (as article I mean he, she, it, etc)

Is there a pronoun I can use as a gender-neutral pronoun when referring back to a singular noun phrase?  Each student should save his questions until the end. Each student should save her questions until the end.


As far as understand, it would make no difference to the operation of an SRAM if you mixed up the order of the address or data pins.  E.g.   Removable non-volatile chips, such as PROMs and EEPROMs, have address and data pin numberings defined, as they need to be consistent across programmers and application circuits.  Why do SRAM chips have numbered data and address pins?  Is there any operation impact if I swap address pins around to make a PCB easier to route?

I am trying to route a pic32 chip to a  chip and having a bit of a hard time getting all 17 address lines and all 8 data lines connected. I am trying to tie the first 16 address pins to portB pins 0-15 and the data pins to portD 0-7.  After thinking about it for a while I realized that I am probably making my life more difficult by trying to line up rb0 with a0, rb1 with a1, etc. All I really want to be able to do is write a 16 bit value to portB and have the majority of the address loaded and ready. If I make pin assignments based on ease of routing, the logical address will be different between the mcu and the ram, but it should at least be consistent. Since nothing else needs to communicate with the RAM, I don't think it will be a problem if the mcu asks for address 0x101 and the RAM gives it address 0x110.   However, I wonder if it is a good idea. If there is some structure internal to the RAM designed to make sequential reads more efficient, or something like that, then I may want to go to the trouble of routing them 1:1. The pins arrangement on both chips fees somewhat random to me, so it would make it a lot easier on me if I could ignore the particular numbers. Is there any good reason why I should or should not do that?


My wife and I often watch videos on the plane together, we used to use our iPad together with a headphone splitter so we could watch a movie together - but then we lost the splitter. Anyway, I'm thinking about getting bluetooth headphones for work and am wondering: Is it possible, for instance, to watch a video / movie on an iPhone (we each have an iPhone 6) or iPad with both a wired headphone plugged into the 1/8" headphone jack, and also have a second set connected via Bluetooth?

Me and my friends want to listen to music together. Two of us have Bluetooth Headphones (Beats Solo2 Wireless, Beats Studio Wireless) and one has a wired headset. Is there any way to use all three of these together?


I'm searching for a sci-fi short story. Back in about 1978, I read a story I'd swear was called "Footprints in the Sands of Time." I'm pretty sure it was written earlier, since it was in a class on classic science fiction. I think it was in a collection of short stories too. I've googled this and similar titles, but no luck.  The plot involves someone going back in time and leaving a capsule of radium behind to prove they made the trip. Time was described as a "coiled spring," where the successive turns were separated by 60 million years (I think).

Many decades ago, I read a short story about a time traveler who asks an archaeologist for help.  He convinces the archaeologist that he can time travel by bringing him back a freshly killed dinosaur (small one.)  The time traveler needs help because when traveling back in time to the age of the dinosaurs he met a girl and wants to transport her back to the present.  However only one person can travel in time at a time so he needs the archaeologist at the other end to wait for the girl.  The archaeologist agrees to help.  Unfortunately after the traveler goes back he and the girl find themselves in the middle of a battle between aliens on Earth.  They are chased by a dinosaur and never make it back to the present.  The archaeologist meanwhile is digging for evidence that the traveler went back in time and the story or my recollection of it ends with that.


There are times when I want to take the previous command's parameters and apply them to the current command.   Here is an example  $ cat foo.txt $ vim foo.txt   I'd like to find a shortcut to not have to type out vim foo.txt

For example, I edit and then run the same source.   vim arbit.py python arbit.py   I know I could run it from within vim, but I want a general solution on Bash. I keep finding situations where I reuse arguments.  How can I do that?


I'm sure this has been asked before but a quick search on Stack Overflow didn't turn up any result.    I've put images on my own site for now but it's quite possible I'll restructure or move hosts at some time and the images would be lost to the community. Is there any recognized free host for storing images referenced in questions and answers on Stack Overflow?

Sometimes images are required to ask questions. Currently images need to be stored on external servers. If the image gets deleted, or the server goes down the question could become far less useful to other people encountering it. I would expect that uploading images would cost reputation, or have a required minimum level to keep spam away. Being able to inline display said uploaded  image would be a plus as well.


I get this error when I try to update my Ubuntu 17.04. I already tried few solutions but nothing worked so far. I get these errors:  Reading package lists... Done W: GPG error: http://archive.canonical.com/ubuntu precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 W: The repository 'http://archive.canonical.com/ubuntu precise Release' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://extras.ubuntu.com/ubuntu precise Release: The following signatures were invalid: C47415DFF48C09645B78609416126D3A3E5C1192 W: The repository 'http://extras.ubuntu.com/ubuntu precise Release' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://us.archive.ubuntu.com/ubuntu precise-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 W: The repository 'http://us.archive.ubuntu.com/ubuntu precise-security InRelease' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://us.archive.ubuntu.com/ubuntu precise-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 W: The repository 'http://us.archive.ubuntu.com/ubuntu precise-updates InRelease' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://us.archive.ubuntu.com/ubuntu precise-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 W: The repository 'http://us.archive.ubuntu.com/ubuntu precise-backports InRelease' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details.

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:     W: GPG error:  trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8BAF9A6F   I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a way to do this without using a terminal?


I have a string as var a = "000020097613 / 0020";. How can I get the string in two different variables which are currently separated by / now?  I want as below:  var b = "000020097613"; var c = "0020";

I have this string  'john smith~123 Street~Apt 4~New York~NY~12345'   Using JavaScript, what is the fastest way to parse this into  var name = "john smith"; var street= "123 Street"; //etc...


Let $A\in \mathcal{M}_{m,n}(\mathbb{C}), B\in \mathcal{M}_{n,p}(\mathbb{C})$. I need to show that  $(AB)^t=B^tA^t$. I know that this is a very well-known property, but I am a bit stuck. So, I considered that $A=(a_{ij})_{1\le i\le m \\ 1\le j\le n}$ and $B=(b_{jk})_{1\le j \le n \\ 1\le k\le p}$ and then I took $X=AB=(x_{ik})_{1\le i\le m \\ 1\le k \le p}$, where $\displaystyle x_{ik}=\sum_{j=1}^{n}a_{ij}b_{jk}$. However, I don't know how to write the elements of $X^t$ now. I mean, I know that $X^t=(x_{ki})_{1\le k \le p \\1\le i \le m}$, but I don't know how to write $x_{ki}$ explicitely. P.S.: I am aware that there are other questions on this website where this was proved, but none of them explains this step that puzzles me. EDIT: I tried to add some more work, let me know what the problem is: $(AB)^t=(x_{ki})_{1\le k \le p \\ 1\le i\le m}$, $\displaystyle x_{ki}=\sum_{j=1}^{n}a_{kj}b_{ji}$ (I just switched $i$ and $k$ in $x_{ik}$'s formula) $B^tA^t=(y_{ki})_{1\le k \le p \\ 1 \le i \le m}$, $\displaystyle y_{ki}=\sum_{j=1}^n b_{kj}\cdot a_{ji}$

How do you prove the following fact about the transpose of a product of matrices? Also can you give some intuition as to why it is so.  $(AB)^T = B^TA^T$


The consensus on the preferred capitalization of English question titles in the Stack Exchange network is sentence case (Would this be an OK example?), not title case (Would This Be an OK Example?). Would it be possible to establish an official convention on the matter? I believe that would help to resolve the kind of conflict when a user edits a question title to one convention and another user wants to revert it back to the original convention. I have  at a site, because I'm involved in this kind of a conflict, but there has been no satisfactory resolution. There's the similar question  but it also suggests automatic conversion to a capitalization convention, which is more extreme.

As an example, this question is titled using sentence case. I've been going to lots of different meta sites (especially this one), and I think the needle bent on my oh-me-oh-my-my-ocd-oh-meter.  Can we please standardize on using either:   Sentence case Title Case AP Style Title Case   ... and then we can look at just converting titles automatically? This would be a switch, of course, but I'd only imagine turning it off on sites where program code or symbols might be present in titles. Or, it could just become part of editing guidelines.    Additionally, is this a horrible idea?   To see the differences between them, you can put any arbitrary title into  (we have no affiliation with them, it's just a tool I sometimes recommend to people).  We would also eventually adopt this for static routes, but I'm mostly talking about questions.


I am using Ubuntu 16.04lts and want to install Remastersys. Pl. show me the answer who is using it.

I'm running the daily Ubuntu image (Yakkety Yak) and I would like to build my own Ubuntu image (alternate right now but instructions for a live image also help) while adding a few PPAs. There are several guides on the Ubuntu Community Help wiki, but they all seem to be outdated. I've also attempted to read Ubuntu's and Debian's code for doing this, but I'm not seeing exactly how they are used.  How do I do this without installing the ancient Trusty Tahr?