How is the codomain for a function defined?

Or, in other words, why aren't all functions surjective? Isn't any subset of the codomain which isn't part of the image rather arbitrary?


Changed Project Name and Now Can't Build In Xcode

I changed my project display name and then changed its name in the project navigator. (same new name for both). I noticed the target name didn't change. Now I'm noticing that I can't find or build the project and my intents are out of scope. I tried changing the target name itself. It would let me click on it to edit but it wouldn't save it unless its as the old name. I also tried cleaning the build folder and restarting Xcode based on SO advice, but it didn't work. What do I do?


What's the relationship between $SL(2,\mathbb{C})$, $SU(2)\times SU(2)$ and $SO(1,3)$?

I'm a beginner of QFT. Ref. 1 states that      [...] The Lorentz group $SO(1,3)$ is then essentially $SU(2)\times SU(2)$.    But how is it possible, because $SU(2)\times SU(2)$ is a compact Lie group while $SO(1,3)$ is non-compact?   And after some operation, he says that the Lorentz transformation on spinor is complex $2\times2$ matrices with unit determinant, so Lorentz group becomes  $SL(2,\mathbb{C})$. I'm confused about these, and I think there must be something missing.   References:   L.H. Ryder, QFT, chapter 2, p. 38.


How do I remove extra Skype icon or ghost icons for removed apps from GNOME shell?

When searching for "Skype" I always see these 2 entries.  There is this duplicate blank Skype icon. Both of them seem to run Skype in the same way.    But I've checked both /usr/share/applications, and ~/.local/share/applications, and can't find the extra icon so I can delete it.    Also as described , sometimes similar ghost icons are present even after removing associated applications.


Charge USB device with power generating by mechanical computer keystrokes

I search on  but I not found an answer.  I want make a output on my keyboard to charge an usb device (ie: mp3 reader or smartphone).  - In first time I want to know if is there a mechanical computer keyboard generating current with keystrokes? (with current generation in keyboard)  - In second time I want to know how is possible to make that?    EDIT #1 :  The  on it in December 30, 2014.  This article describes a keyboard, which can among other features, harvest energy. But the abstract does not reveal the harvesting method and it is not clear if the harvested energy is sufficient to fulfil its own tasks.    EDIT #2 :      This paper presents a hybrid energy harvester which combines piezoelectric (PZT) and electromagnetic (EM) transduction mechanisms to scavenge vibration energy from a keyboard. The system comprises of improvements to the dome structure presented in previous studies, in which only PZT transduction mechanism was used to harvest 16.95 μW of experimentally verified power. An in-house modeling and simulation tool is first introduced in this work to evaluate the integration of EM transduction into the PZT system. The tool combines analytical mechanical equations and FEM results for magnetic fields for the optimization of the electromagnetically generated power. Two designs of different cost are then compared. It is concluded that the design utilizing the frequency-up-conversion technique at an incrementally higher cost is superior due to significantly higher contribution to the generated power compared to the alternative implementation without frequency-up-conversion. Modeling and simulations show an additional 2.81 μW power can be generated through EM integration to the previous PZT based keyboard energy harvester system.   According to :      only 4077 years needed for 1 kWh..    I think (fix me if I mistake) USB device need 500 mA to charge 5V.   - I ask me how many times is needed to charge an usb device?    EDIT : I feel that this question goes beyond me


Maximum angle between curved characters makes QGIS curved label invisible

When labeling a curved line in QGIS 2.2, and setting Placement to 'Curved', the behavior of 'maximum angle between curved characters' is not intuitive, and I haven't been able to find documentation on it.  The line I'm trying to label is pretty jagged (it's a hiking trail).  If I leave the 'maximum angle' settings both at 20 (default), no label is drawn.  If I crank the values up to 45, the label is drawn but it is very jagged just like the trail, and illegible.  If I crank the values down to 30, the label disappears again.  So, it seems like these values are being interpreted like so: "If any generated character would be more than x degrees rotated from the previous character, then do not draw the label."  Whereas I was hoping the values would be used as a sort of filter / smoothing algorithm: "Rotate the characters as needed such that each character's rotation is within x degrees of the adjacent characters' rotations."  Can anyone provide a more clear interpretation?


Regular expression to validate phone number

I got this regular expression for validating phone number  /^(\+)?[\d\s\-\(\)]+$/   This validates most of the phone numbers except -     +01 (555 236 4960   here the closing brace is missing but it does not validate this. What should be changed in the existing regex so that it matches the closing brace as well


Radon measure on locally compact Hausdorff spaces

Suppose $\mu$ is a Radon measure on a locally compact Hausdorff space $X$ such that $\mu(\{x\})=0$ for all $x\in X$ and $A \in B_X$ satisfies $0<\mu(A)<\infty$. Then for any $\alpha$ such that $0<\alpha<\mu(A)$, there is a Borel set $B\subset A$ such that $\mu(B)=\alpha$.  I am reviewing measure theory for my exam and got stuck on this question. Can any one help me ? Thank you very much.


Check for uniform convergence of a function series

$\sum_{n=1}^{\infty}\dfrac{1}{n(1+(x-n)^2)}$  The question has a few parts and the one im struggling with is checking for uniform convergence on $[0,\infty)$.  I've managed to show that this series  converges for any $x\in[0,\infty)$ and that the seriesconverges uniformly on every $[a,b]\subset[0,\infty)$. My intuition tells me that the series should be uniformly continuous, because even though it's terms are sometimes close to $\dfrac{1}{n}$ when $n$ is close to $x$, almost all terms are proportional to $\dfrac{1}{n^3}$.  I feel like I'm overlooking something obvious here. I would appreciate any hints.


A proof by strong induction that $a_n\le3^n$ where $a_n=a_{n-1}+a_{n-2}+a_{n-3}$

I am not sure whether this is right. Can anyone verify, whether this proof is valid? Thanks!        Define a sequence $\{a_n\}_{n\ge0}$ as follows:   $$a_0=1,\qquad,a_1=3,\qquad,a_2=9,\qquad,a_n=a_{n-1}+a_{n-2}+a_{n-3}\text{ for }n\ge3.$$   Prove that for any positive integer $n$, $a_n\le3^n$.        Proof. Let $P(n)$: $a_n\le 3^n$, $n$ is a non-negative integer.      (i) Base case:         Consider when $n=0$. LHS$=a_0=1$, RHS=$3^0=1$ $\therefore$ LHS$\le$RHS, then $P(0)$ holds.   Consider when $n=1$. LHS$=a_1=3$, RHS=$3^1=3$ $\therefore$ LHS$\le$RHS, then $P(1)$ holds.   Consider when $n=1$. LHS$=a_2=9$, RHS=$3^2=9$ $\therefore$ LHS$\le$RHS, then $P(2)$ holds.         (ii) Inductive case:   Assume $P(i)$ is true for $0 \le i \le k$, $k\ge2$.      (iii) Inductive conclusion: Consider $n=k+1$.   $$ \begin{align*} \mathrm{LHS}=a_{k+1}&=a_k+a_{k-1}+a_{k-2} \qquad\text{(by definition, since $k\ge 2$)}\\                     &\le 3^k+3^{k-1}+3^{k-2} \qquad\text{(by Induction Hypothesis)}\\                     &=3^k(3^{-1}+3^{-2}+3^{-3})\\                     &=3^k\left(\frac13+\frac19+\frac1{27}\right)\\                     &=\frac{13}{27} 3^k\\                     &\le 3^{k+1} = \mathrm{RHS} \end{align*} $$   Therefore, by the Principle of Strong Induction, $P(n)$ is true for all non-negative positive integers $n$.


The 1st book starts with the main character (Paul), a WWI soldier climbing a giant tree in the middle of the battlefield and finding a giants castle. Other episodes include Tik-Toks  and Paul on (John Carter's) Mars.


Non-rectangle select in Windows command line

Is there any way I can disable the stupid rectangle selection mode thing in the Windows command line? I want to select line by line like normal. Currently it's a giant pain when I need to copy things that span multiple lines because the copied text gets lineendings where there shouldn't be any...


How do I get my device detected by ADB on Linux?

I just got my shiny new Wileyfox Swift – and before putting it to use I want to oem unlock and root it (as I usually do with new devices ;) Trouble is, though  is enabled on the device, and a corresponding line in /etc/udev/rules.d/51-android.rules exists, the device is not seen by adb devices.  I know there are several answers scattered around this site, but they are either hard to find, just cover a specific device, or don't cover all steps I finally needed. So I take this as a chance for a canonical, device-independent question and give it a detailed answer below:  How can I get my Android device seen and used by adb on Linux?


I am doing  problem in Leetcode.  The original code is:  /**  * // This is the interface that allows for creating nested lists.  * // You should not implement it, or speculate about its implementation  * public interface NestedInteger {  *  *     // @return true if this NestedInteger holds a single integer, rather than a nested list.  *     public boolean isInteger();  *  *     // @return the single integer that this NestedInteger holds, if it holds a single integer  *     // Return null if this NestedInteger holds a nested list  *     public Integer getInteger();  *  *     // @return the nested list that this NestedInteger holds, if it holds a nested list  *     // Return null if this NestedInteger holds a single integer  *     public List<NestedInteger> getList();  * }  */ public class NestedIterator implements Iterator<Integer> {      public NestedIterator(List<NestedInteger> nestedList) {      }      @Override     public Integer next() {      }      @Override     public boolean hasNext() {      } }  /**  * Your NestedIterator object will be instantiated and called as such:  * NestedIterator i = new NestedIterator(nestedList);  * while (i.hasNext()) v[f()] = i.next();  */   I realize that NestedIterator constructor use a list of interface as parameter. I feel confused why it doesn't implement the interface somewhere, but use it directly in list. I thought we shouldn't use interface directly. Thanks!


It takes at least 3 times longer to copy files with shutil.copyfile() versus to a regular right-click-copy > right-click-paste using Windows File Explorer or Mac's Finder.  Is there any faster alternative to shutil.copyfile() in Python? What could be done to speed up a file copying process? (The files destination is on the network drive... if it makes any difference...).  EDITED LATER:  Here is what I have ended up with:  def copyWithSubprocess(cmd):             proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)  win=mac=False if sys.platform.startswith("darwin"):mac=True elif sys.platform.startswith("win"):win=True  cmd=None if mac: cmd=['cp', source, dest] elif win: cmd=['xcopy', source, dest, '/K/O/X']  if cmd: copyWithSubprocess(cmd)


I have a PHP file that does some task in consistent intervals.   I have placed that PHP file inside a custom module folder, but I found that Drupal functions like drupal_set_message() are not available inside the PHP file.   How do I include Drupal functions inside this PHP file? How do I set up this php file to be run as a cron job?


$N(\theta,\theta)$: MLE for a Normal where mean=variance

$\newcommand{\nd}{\frac{n}{2}}$For an $n$-sample following a Normal$(\mu=\theta,\sigma^2=\theta)$, how do we find the mle?  I can find the root of the score function $$ \theta=\frac{1\pm\sqrt{1-4\frac{s}{n}}}{2},s=\sum x_i^2, $$ but I don't see which one is the maximum. I tried to substitute in the second derivative of the log-likelihood, without success.  For the likelihood, with $x=(x_1,x_2,\ldots,x_n)$, $$ f(x) = (2\pi)^{-n/2} \theta^{-n/2} \exp\left( -\frac{1}{2\theta}\sum(x_i-\theta)^2\right),  $$ then, with $s=\sum x_i^2$ and $t=\sum x_i$, $$ \ln f(x) = -\nd \ln(2\pi) -\nd\ln\theta-\frac{s}{2\theta}-t+\nd\theta, $$ so that $$ \partial_\theta \ln f(x) = -\nd\frac{1}{\theta}+\frac{s}{2\theta^2}+\nd,  $$ and the roots are given by $$ \theta^2-\theta+\frac{s}{n}=0. $$ Also, $$ \partial_{\theta,\theta} \ln f(x) = \nd \frac{1}{\theta^2} - \frac{s}{\theta^3}. $$


What is the life expectancy of a Wookiee?

At lunch, my coworkers and I were discussing The Force Awakens, and started questioning Chewbacca's age.  A quick check of  and it says he is possibly about 230 years old as of Episode VII.  Following the  link on that page, Wookieepedia claims that they live to be 400 years old.  Do we know from canon what the average life expectancy of a Wookiee is?


Console Application to be run as GUI as well

Before anyone marks this as Duplicate, Please read   I have a process which is Windows Application and is written in C#.    Now I have a requirement where I want to run this from console as well. Like this.    Since I need to show output to console, so I changed the application type to Console Application    Now the problem is that, whenever user launches a process from Windows Explorer (by doubling clicking). Console window also opens in behind.    Is there is way to avoid this ?  What I tried after @PatrickHofman's help.   Followed    But I still have problems   When I do this , the console opens in new window. I don't want that. When I do this , i.e. pass -1 to AllocConsole there are other problems which occur, as mentioned in the referred link.


Does light accelerate or slow down during reflection?

After all, it does change direction when reflection occurs. So shouldn't it also accelerate? And since the acceleration cannot increase the speed of light, mustn't it slow down?


Unable to reset root Ubuntu user password via GRUB as it prompts for password when selecting "drop to root shell" in Grub advanced options

I changed my main account password on Ubuntu server 15.06 a few days ago and promptly forgot it.  I have tried dropping into the root shell via Grub, but it actually prompts me for the root password again "Please enter root password to enter maintenance mode, or hit Ctrl-D to continue".  Hitting ctrl-D just brings me to the login prompt.    I have physical access to the box, and this UI response seems inconsistent with what's posted here:   Is there a way to reset the "root" user password in Ubuntu 15.06?


Can you show why zero divided by zero does not equal zero?

I was talking about division by zero with my discrete math instructor, and it was explained to me that dividing can be broken down into simpler terms, i.e: Consider 6 divided by 3. To reach the answer consider how many times 6 can repeatedly have 3 subtracted from it, such that it comes to zero. 6 - 3 once is 3, and twice is zero. The answer thus is two.  So, I said that zero divided by zero then is already zero, and no subtraction ever need take place. Therefore the claim is that $\frac{0}{0} = 0$  How can we show that this does not work well? My instructor claimed that there is a smart way of showing how this will not work, but could not remember what it was. Does anyone know what it might be?


Can't login as user after upgrade 12.04 to 13.04

After upgrade I can't log in. Error message:  Could not update ICEauthority file /home/username/.ICEauthority   This is on a system with 2 partitions. This installation is on /dev/sda5 type ext4. Could this partition be read only? Maybe because of an error? If so, how can I repair this partition? BTW, I can login as guest.  Help highly appreciated...  Update  User login works if I use recovery mode.  Also, the partition is shown as read only. I can change this using the recovery console, but it looks like it changes back to read only if I'm returning to normal boot process out of the console.  I tried to repair the partition with  sudo rack.ext4 -v -f /dev/sda5  ( a command I found somewhere, without really knowing what I'm doing) but the results didn't show an error. –


I have been noticing that the consecutive login marker in the user profile is not working right.  This marker can be found in the visits status section on the visited line.  I logged in everyday since I registered and it still states that I am never consecutively logging in. I have checked and rechecked if its something I am not doing right, but I have even counted when I login and it should report a lot more consecutive days then it does.  Can anyone please check on this subject and see if I am doing something wrong? It's pointless to have a marker if it doesn't work right.


About the proof of square root of 2 is irrational

I looked at the proof of $\sqrt 2$ is irrational. In first step we assume that $\sqrt 2$ is rational. Then we say it should be written as $\frac ab$ if it's rational.After that we assume gcd(a,b)=1 and end of the calculations we conclude that a and b are even numbers.So there is a common factor but we assumed that gcd(a,b)=1 so it's a contradiction , $\sqrt 2$ must be irrational.The thing that I don't understand why we assume that gcd(a,b)=1 ? We assume that $\sqrt 2$ is rational it's okay but why we need to assume gcd(a,b)=1.I don't think it's the need of being rational ?


I see no foul language on comments, answers or questions, but what about profile info?   Is foul language allowed there? Check out this


What is the meaning of posts.communityowned date?

There is a field in the posts table named communityowneddate. What is the meaning of that field? And in what case is the post owned by community?


Why are some function in python called as attributes and others not?

In Python everything is object, but some methods are not called as attributes, but you pass them the instance of object as parameter. For instance:  function len() expects object - len(str) seems logical, because it clearly shows that strings are immutable.  But why then str.find() is called as attribute of str?  I thought that it is because len excepts more then just one type of object, but this could be solved with polymorphism, right?  Is there any reason for some functions to be called as func(obj) and some as obj.func()?


I am new to Independent Component Analysis (ICA) and have a rudimentary understanding of the method.    I understand that PCA finds vectors on which the projected data has maximum variance. ICA, on the other hand, finds vectors on which the projected data is statistically independent however, what those ICA is actually producing as a benefit when applied to a dataset ?  Let say that I want to apply FastICA to the iris dataset of scikit-learn. (maybe not the best example as it only have 4 features however I use it for illustration)  from sklearn import datasets from sklearn.preprocessing import Imputer imp = Imputer(missing_values='NaN', strategy='mean', axis=0) imp.fit(X) X = datasets.load_iris().data  ica = FastICA(n_components=2) X_trans = ica.fit_transform(X) print ica.components_ plt.scatter(X_trans[:, 0], X_trans[:, 1])     In this example I selected 2 components for ICA for visualization purpose however there should be a way to select the optimal number of components ? What does the plot is supposed to show me in this example ? What objet or property the vectors correspond to ?  How can this be used in practice?  I also find  and went through it however my question is a bit more specific. What ICA has to offer if applied on a dataset. In the example I gave, I use ICA. Why one would use ICA? What are the property of the vectors produced by ICA and in the example ?


Ubuntu installation on SSD + HDD combination

I have an SSD + HDD combination for my laptop. I have my SSD running Windows 10 and I want my HDD to get used for all Ubuntu's stuff (bootloader, kernels, root directory, swap, home, etc.). Please tell me how can I achieve that in Ubuntu partitioning, with what should be type of partition.


So, I’m level 46 with 100 smithing and enchanting. I want to make the best armor I possibly can, so I was wondering how to break the smithing cap with potions the best way that was intended. What I mean by this is I don’t want to exploit the system for smithing to be boosted to some ridiculous number like 1440%, rather, what is the best boost I can do to my armor and weapons while not feeling like a cheating as*wipe. I also understand alchemy will most likely be needed, so I’ll be sure to 100 that as well.


Clean install of 12.10 - reused 12.04 /home. Cannot start unity/login for legacy/imported user

I have separate disks for / and /home.  I did have 12.04 installed but decided to do a clean install (format and install) of 12.10. I created my user at install.  I should be able to login, right? Well, I can't.  LightDM comes up with my username and I enter my password, but it just goes back to the login screen.  Is there something I should delete from my old profile or ~?    I can login to the terminal. My files and directories are there in /home.


Is there really a way to make a true toon shader material in Cycles?

Is there a way to make a true toon shader material in Cycles?  Here's, in order of importance, what would be ideal to find in such a shader:   Must use Cycles Must be an actual shader Must not rely on lighting Must be independent of camera position Must react directly to lighting rather than manually having to change it to emulate it Should be easily made into a node-group Should have the following configurability:   Main color Darkness color Shadow depth (how far the shadow goes from the unlit side)    Below, I'll be listing some already-found methods and their flaws:    Cycles's Toon BDSF:  Source: Blender  Result:    Node setup:    Cons:   Not a clear-cut two-color shading Reacts to diffusion of surrounding objects      Mask & Ramp:  Source:   Result:    Node setup (Compositor):    Cons:   Very grainy Does not support colour textures Not easy to change shadow depth in a nodegroup Not a material, requires compositor Requires use of object indexes     Shadeless Fresnel:  Source:   Result:    Node setup:    Cons:   Uses camera's direction Ignores lighting Not easy to change shadow depth in a nodegroup     Shadeless Normal:  Source:   Result:    Node setup:    Cons:   Ignores lighting Direction of shadow is manually changed Not easy to change shadow depth in a nodegroup   However, this one is easily the best one. It's pretty great, and would work still images very well.    That's all I've got. Does anyone else have any methods that fall under most of the criteria I listed above? Also note that OSL is totally fine, if it works.


Compute $\int_{0}^{\infty}\frac{x\sin 2x}{9+x^{2}} \, dx$

$$\int_{0}^{\infty}\frac{x\sin 2x}{9+x^{2}} \, dx$$   Some rearranging eventually gives $$\int_{0}^{\infty}\frac{x\sin 2x}{9+x^{2}} \, dx = \frac{-i}{2}\int_{-\infty}^{\infty} \frac{xe^{2ix}}{9+x^{2}}$$ Consider $f(z) = \frac{ze^{2iz}}{9+z^{2}}$ and the contour $\gamma$ of the semicircle laying in the upper half of the plane:   Let $\gamma_{R}$ denote the circular part with radius $R$ and $\gamma_{L}$ denote the part lying on the real axis with length $2R$.   Computing the residue at the only pole, $z = 3i$, we have that $$\oint_{\gamma}f(z) \, dz = \frac{i\pi}{e^{6}} $$ On the other hand, \begin{align*} \oint_{\gamma}f(z) \, dz &= \oint_{\gamma_{R}}f(z) \, dz + \oint_{\gamma_{L}} f(z) \, dz \\ &= \oint_{\gamma_{R}} f(z) \, dz + \int_{-R}^{R} \frac{xe^{2ix}}{9+x^{2}} \, dx \end{align*} We may evaluate the first integral in the usual way by parameterizing the contour and taking $z = Re^{i\theta}$. \begin{align*} \oint_{\gamma_{R}} f(z) \, dz = \int_{0}^{\pi} \, \frac{R^{2}e^{2i\theta}e^{2i\cos\theta}e^{-2R\sin\theta}}{(9+R^{2}e^{2i\theta})} d\theta \end{align*}  I'm aiming to show that this integral goes to $0$ as $R$ goes to infinity. This gives the desired result as the factor of $\frac{-i}{2}$ is all that is missing according to WolframAlpha. I'm not sure how to finish it though.


How can I create an image with a round globe like center?

How did this person create this shot of a tree in the center, the buildings circling it, and grass all around the edges?   I love this example and someday I want to make a similar one with snow and snowflakes.


Whats the best method in having multiple domains online with the same content so that it does not affect SEO.  Say a www.domain.com and www.domain.com.au. The *.com.au domain has significant SEO history and the *.com domain is brand new and currently only has a 301 redirect to the .com.au domain.  Would I just put a copy of the same website up on both domains or will a redirect from one domain to the other do the trick?  What would be the best method to go about this?


I have recently started studying RS flip-flops. I noticed that for the SR NOR Flip-Flops most of the images online, as well as my text, have the 'Set' input attached to the NOR gate that outputs 'not-Q', some sources said that it is designed this way because we want Q to be '1' when S is pulsed '1' and vice versa.    However when dealing with NAND SR Flip Flops this rule of making Q '1' by pulsing S to '1' does not work. Futhermore some of the online images of NAND SR Flip-Flops have the 'Set' input on the gate that outputs Q and others have the 'Set' input on the gate that outputs the compliment of Q.    Please excuse my rather elaborate question but in summary, I would like to know: 1) Does the R and S inputs have to be attached to specific gates in the flip-flop. 2) If yes to '1)' can someone please explain  why this is, for both the NAND and NOR SR Flip-Flop.  Thank you in advance.


Caused by: java.lang.NullPointerException: Attempt to invoke virtual   method 'void com.andremion.counterfab.CounterFab.setCount(int)' on a   null object reference   Code  @Override protected void onResume() {     super.onResume();     fab.setCount(new Database(getBaseContext()). getCountCart());      if (adapter!=null )     {         adapter.startListening();     } }


How to escape special characters in mysqli

I have searched and tried a number of methods but I can't find one that works with the coding I currently have (which was learned from here,  thanks).   Might I ask you to indulge me and lend a hand please.  I am suffering with the apostrophe when a textbox gets something like harry's typed into it.  The form data is sent to a php file that adds the record like this :-    if ($stmt = $mysqli->prepare("INSERT lists (group, owner, pattern, gender) VALUES ('$_POST[Group]','$_POST[Owner]','$_POST[Pattern]','$_POST[Gender]')")) { $stmt->execute(); $stmt->close(); } // show an error if the query has an error else { echo "ERROR: Could not prepare SQL statement."; }     So how do I use "mysqli_real_escape_string" in the above?  Of course, if there is a better solution I would be only too pleased to hear.  Thanks for your help.  Obviously I am an absolute dim git.  The page says "If this question is different, please edit it to explain how it is different".  I can't even see how the linked page is even similar!  I have now spent three days trying to sort this but without success  (yes I did try before I posted here) and I can't see anywhere any example of what I should be doing.  Can anyone please,  please, please,  explain how I should do this?  Example code would help me immensely.  It seems that this site helps when someone has at least some understanding of the whole but not when one is absolutely thick.  The replies,  though well intended and appreciated,  were as helpful as a reply simply saying "The number 7 bus doesn't go this way".  Sorry guys.


Installing GSON JAR file and using it with Java

I am relatively new to Java and am using it with VS Code. I have downloaded the JAR file for GSON and I would like to use it in order to parse through a JSON structured string and assign it to string variables.   The only issue I am having is actually using the GSON api with the java class that reads through the JSON string and parses it. After downloading the JAR file, how do I import it into my java class that contains the readString method?   I am using VS Code as the IDE and am unable to find any documentation for VS Code  Any advice would be amazing!


How to remove the path with an nginx proxy_pass

I have a running web-application at http://example.com/, and want to "mount" another application, on a separate server on http://example.com/en. Upstream servers and proxy_pass seem to work, but for one issue:  upstream luscious {  server lixxxx.members.linode.com:9001; }  server {   root /var/www/example.com/current/public/;   server_name example.com;    location /en {     proxy_pass http://luscious;   } }   When opening example.com/en, my upstream application returns 404 not found /en. This makes sense, as the upstream does not have the path /en.   Is proxy_path the right solution? Should I rewrite "upstream" so it listens to /en instead, as it root path? Or is there a directive that allows me to rewrite the path passed along to upstream?


Merge two datatables based on one primary column in C#

I have two datatables as shown in screenshot (table 1 and table 2). I want to merge these tables based on the Name column and create the result table as you see ...   Can you please explain to me how to achieve this?   Note: my table is simple datatable in c# not SQL table Thanks


How do grad schools look upon students with chronic illnesses?

The chronic medical illness has affected my ability to take the most rigorous schedule and led me to withdraw from one class and also take a year break in my undergraduate education.  I'm wondering how this will affect my grad school chances. I have excellent LOR and GRES, good GPA.  Should the illness be discussed in SOP or elsewhere?


I accidently hit a key combo and it messed up my view

My hands accidentally fumbled over the keyboard and the 3d view ended up with a dark volume that extends out forever from a point. Anything outside that view is hidden. I am unable to recover the file for some reason and may of just lost about 20 hours of work as I am unable to find out what I did.


If $[K:F] = 3$, show a non square in $F$ is a non square in $K$

Let $F \subset K$ be finite fields with $[K:F] = 3$. Show that if $\alpha \in F$ is not a square in $F$, it is not a square in $K$.  My attempt:  $[K:F] = 3 \implies \forall x \in K$, $x = \beta_1a_1 + \beta_2a_2+\beta_3a_3$, where $\beta_1, \beta_2, \beta_3 \in F$ are basis for K. So if $\alpha \in F$ not a square then $x^2-\alpha = 0$  has no solution in F. So then we have to show that $(\beta_1a_1 + \beta_2a_2+\beta_3a_3)^2 - \alpha = 0$ also has no solutions.  I am not sure if I am even headed in the correct direction. Any help is appreciated.


Show that $\lim_{x \rightarrow 0} \frac{\sin(x)}{x} = 1$ without using L'Hopital's rule

A student I tutor asked me this question. The L'Hopital's approach is quick and easy, but is there a direct but rigorous way to show this without invoking L'Hopital's?


Why is my guide in Terraria not respawning?

I spawned in the WoF and then when I died to it, my guide didn't respawn. I waited like 20 in-game days, still didn't respawn. I then waited a real life day then came back and he still didn't respawn. All of my other NPCs are spawning, and I already checked and all of my houses are valid.


Close as a duplicate on mobile: Lots of Vertical Scrolling

Attempting to use the site with a Nexus 4.  I came across a question that was a duplicate, so I found the dupe and voted to close.  The only problem:  the button is at the bottom of the modal.  While in mobile view, that means lots of painful scrolling all the way through the question and its answers.  On the normal site this isn't an issue:    ...but on the mobile site...    Here's an example:    This definitely affects usability while on mobile.


Disable Drag (not drop) in the Windows Explorer Navigation Pane

I find myself occasionally grabbing some random folder and dropping it into some other random folder in the Windows Explorer navigation pane (the left hand pane with the folder list).   The really big problem is that I am sometimes unaware that I did it, and even if I do realize, I've no idea what folder went where (thankfully, if I am aware I can CTRL-Z and undo the move).  Is there any way to either disable dragging only, of if that's not possible, dragging and dropping in that pane?


How to import a template file with HTML markup to use for sending email notifications?

I want to send the email notifications to users of the site. I have a basic template file with the HTML markup I want to send in the email.  How do I import that HTML file (which is in the root folder of the project) in my module?


I'm running sudo apt-get update to update a new install on Ubuntu 16.04.2 64 bit. I get the following error message:  The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.   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.   E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs   E: Some index files failed to download. They have been ignored, or old ones used instead.   I tried using the apt-cdrom command to mount the cdrom but it seems to not work, I think i'm typing it in wrong as i am new to linux and have only been using it for a few weeks.I try to type in commands and it comes back as command cannot be found.the apt-cdrom has great info on how to probably solve this problem but I'm not sure how to use it or how to properly type the commands in.


How to convert RPM package to a format meaningful to Ubuntu

I'm using a special program that has only .rpm version available as installer. As I need to run it on Ubuntu, Is there a way to install it in Ubuntu?


Each question carries 0.5 marks vs Each question carries 0.5 mark

Which one is right and why? Does the answer change if instead of 0.5 we have let say 5.


What are the advantages from using as and then comparing with null over is and a direct cast?

Consider this code:  var someObject = GetSomeObject as ISomeInterface;     if (someObject != null) {    // do someting, not only one method call with this object, so don't expect null propagation to be handy   someObject.CallSomeMethod(); }   Is that preferable over this:?  var someObject = GetSomeObject(); if (someObject is ISomeInterface) {    // do someting   ((ISomeInterface)someObject).CallSomeMethod(); }   What are the differences and when would I chose what to use?  Is it just about readability?


Difference between multilevel modelling and mixed effects models?

What is the difference between Multilevel/Hierarchical Modelling and Mixed Effects Models?    Wikipedia considers them to be the same, i.e. two different names for the same thing. But I think they are not exactly the same. Could anybody explain the theoretical difference?   Maybe the "Mixed Effects Models" is just one approach to solve Multilevel problems?


If $a^{m}=b^{m}$ and $a^{n}=b^{n}$, show that a=b

Question: Suppose that a and b belongs to an integral domain.   If $a^{m}=b^{m}$ and $a^{n}=b^{n}$, where m and n are positive integers that are relatively prime, prove that a=b.   Well, m and n are relatively prime so gcd(m,n)=1 holds. In fact, from the fact that the gcd of any positive integers: gcd(m,n)=1=ms+nt for some integers s,t.   Raising the element a to ms+nt: $a^{ms+nt}=a$  A good bit of hint here would be helpful.  Thanks in advance.


Best way to convert Pascal Case to a sentence

What is the best way to convert from Pascal Case (upper Camel Case) to a sentence.  For example starting with  "AwaitingFeedback"   and converting that to  "Awaiting feedback"   C# preferable but I could convert it from Java or similar.


Two different names in EU and US passports?

I am a USA-Italy dual citizen about to change my last name through marriage. In Italy I can't change my name though, so I'll have my Italian passport in one name and the US passport in another.   Is this going to cause problems when I travel between the two?   For example, if I leave the US for Italy I assume I'll want to fly on the Italian passport, but on the way back what happens if my Italian passport flags a "doesn't have US ESTA" issue with the airline? Or will US CBP be confused when I arrive with a different name (US name) than the name supplied by the airline (Italian name)?  If anyone has successfully done this I'd love to hear from you!I saw the other answers on this but they don't address Europe and ESTA specifically.


Why is my account closed to new questions?

Why am I getting this message when I press "Ask Question": You have reached your question limit Sorry, we are no longer accepting questions from this account. See the Help Center to learn more.  I have no idea what I would change in any of the questions I have asked. I've tried deleting all my questions that were not answered.  No change. What do I do next?


Where's the Device Manager in Ubuntu 15.10?

In the  which has this notice:     Needs Updating   This article needs updating to include the latest versions of Ubuntu.   It says it is located here: System > Administration > Device Manager.  But such a menu hierarchy doesn't exist anywhere.


Generate Email Addresses with Special Characters

I am tasked with generating an email address for new users in our environment who may have special characters (such as an umlaut and accents) in their full names.  While some email systems can handle these characters I am being told to generate email addresses that can convert these characters to a standard ASCII format.  So for example, John Señior would be created as john.senior@...  and Jane Fraü would be created as jane.frau@...  Has anyone found a regex expression or library that can handle such a requirement.  UPDATE - I am planning on performing the replacement in PowerShell, but could use any Windows compiled libraries as well.


Can I purchase an EV SSL for a single subdomain?

Hey everyone sorry for the noob question, I was getting different answers on Google.  My question specifically is: Am I able to purchase a EV SSL for each of my sub-domains.  Thanks in advance.


Group of order $pqr$, $p < q < r$ primes

Let $G$ be a group such that $|G|=pqr$, $p<q<r$ and $p,q,r$ are primes. i need to prove that:   There exists a subgroup $H$ such that $H\unlhd G$ and $|H|=qr$. $G$ is solvable. $r$-Sylow subgroup of $G$ is normal.   I know the proof that $G$ isn’t a simple group, and by that I think I can prove the second part of the question, but I can’t manage to prove the first and the third parts of the question.


Why does Minkowski space provide an accurate description of flat spacetime?

What is the chain of reasoning (beginning, of course, from observations about the universe) that leads one to predict that Minkowski space provides an accurate description of space-time in the framework of special relativity?  That is, why should flat space-time have the Minkowski metric  $$\eta = \left(\eta_{\alpha\beta}\right) = \left( \begin{matrix} 1 & 0 & 0 & 0 \\ 0 & -1 & 0 & 0 \\ 0 & 0 & -1 & 0 \\ 0 & 0 & 0 & -1 \end{matrix}\right)\,?$$


I wrote the following into the Python interpreter today:  >>> def test(): ...     for c in ['a', 'b', 'c', 'd']: yield c ... >>> a = test() >>> a <generator object test at 0x2556a00> >>> a.next() 'a' >>> a.next() 'b'   This was surprising to me. Shouldn't test return (or yield) one of the elements in my list, not a generator which yields them?  A second function which uses "return" behaves as expected:  >>> def test2(): ...     for i in ['a', 'b', 'c', 'd']: return i ... >>> b = test2() >>> b 'a' >>> b 'a'   Why is this so? Where in the documentation describes this behaviour?


I'm currently finishing up my last year of study as an undergraduate mathematics major at a top 2 public school.  I've been interested in getting a phD in mathematics for some time now, but my GPA and work in some classes in my 1st and 2nd years leaves a lot to be desired.   Let's just say I got pretty bad grades in important classes.  Since then, I've worked my but off and currently have around a 3.3 GPA.  Luckily, I was accepted into a Statistics/Computer Science related Masters program.  In this program, I will have the opportunity to take electives and plan to take some higher level math classes.    My question is, will doing very well in my masters program next year override my poor performance as an undergrad? Also, should I be really trying to get a research position this summer?


how to identify malformed lines in the text editor

I was trying to download cmatrix and it has malformed lines i went to a bunch of different forums and i couldn't find out how to identify a malformed line how do i identify malformed lines in the text editor im using ubuntu 18.04.2 LTS the text editor with the malformed lines


Completely remove the broken installation and merge its partition

I have 2 bootable installations, one of them is broken, meaning I can't boot it but it does appear in the boot menu. I want to completely remove the broken one and merge its partition with the my current installation. How can I do this safely?  UPDATE:  I can't figure out how to merge sda1 and sda6, sda6 being my main partition.


Set background image in CSS using jquery

I am trying to set the background image for one of my html element using jquery
     <input type="text" id="globalsearchstr" name="search" value="" class="rmz-txtbox">     <input type="submit" value="&nbsp;" id="srchbtn" class="rmz-srchico">

  $("#globalsearchstr").focus(function(){     $(this).parent().css("background", "url(/images/r-srchbg_white.png) no-repeat;"); });   but this never works.On focus only change happens is that a style attribute is added to HTML, like this

   No change in CSS happens.


It's not a given that we're always connected to the internet, so why not include some offline features in the Stack Exchange App?  Something similar to Gmail app like    Currently the favorite questions are missing in the Android App.  Once they are back, can we have access to favorites in offline mode?  Once  connected to the internet again they could be synced to your device for the latest updates.  I tried to make a sample screen:    This image uses fake data


Characters displaying fine then inserting into mysql with question marks

I'm trying to parse a text file using PHP.   In my database I have data which shows in phpmyadmin like this Triste o melancÃ³lico  And once it's retrieved it displays just fine on my website.  Now the issue has come when I try to parse this text file. I will have a word such as Etimología  Now I load the text file, parse it and if I echo the parsed data to the page it will display fine, no question marks / unwanted characters in replace of the í. The thing is if I go to insert the data into my db the special character í is being switched over to a question mark.  I've tried using  mysql_query("SET CHARACTER SET utf8");   After my sql connection but it did not make a difference.  Does anyone have any ideas as to why new text with special characters are being inserted as question marks, when pre existing text with special characters is working just fine?  Thanks


Extract complete pixel values inside a geometry

I'm trying to write an earth engine script which extracts the pixel band values inside a polygon. (geometry)  Only for pixels completely within the polygon.  The polygons will be quite small. (field size)  I have looked through the docs, and searched for this, but am unable to find a solution.  Have only found statistical reductions.  // get the dates var startDate = ee.Date.fromYMD(2018,1,1); var endDate = ee.Date.fromYMD(2018,2,1);  // Create a geometry representing an export region. var myGeometry = ee.Geometry.Polygon( [[[-61.15985870361328, -32.94904673848672],       [-61.152305603027344, -32.944797148619905],       [-61.15659713745117, -32.9395388987784],       [-61.16432189941406, -32.94378874137744]]]);    var landsatCollection = ee.ImageCollection("LANDSAT/LC08/C01/T1_SR");  // Filter image collection to dateRange of interest var landsatDateCollection = ee.ImageCollection(landsatCollection .filterDate(startDate,endDate));  //Filter to AOI. var landsatAOI = ee.ImageCollection(landsatDateCollection .filterBounds(myGeometry));  // Filter to image with least clouds var landsatBestImage = ee.Image(landsatAOI .sort('CLOUD_COVER') .first());  // Load a landsat image and select three bands. var landsatDownload = ee.Image(landsatBestImage) .select(['B4', 'B5']);     ///////// //Added code that was improved after Jon's comments /////////   // generate a new image containing lat/lon of the pixel and reproject it to Landsat projection var coordsImage = ee.Image.pixelLonLat().reproject(landsatDownload.projection());  var joinedImage = coordsImage.addBands(landsatDownload);  var valuesList = joinedImage.reduceRegion({   reducer: ee.Reducer.toList(4),   geometry: myGeometry }).values().get(0);  print(valuesList);   Jon's inspiration on the MODIS script allowed the modification above.  The valuesList now contains all the pixel information.  To see how to Export the data in valuesList to a CSV see


In many scripts in my organisation and even on online tutorials, this is a common if clause I come across :  if [ $# -eq "somethng" -o $# -eq "somethng" ]   what does this $# condition match—some user input by default? Can this be used on command line directly too??


What's the best way to create a list of tuples containing values taken from an array?

I have three arrays/lists:  list1 = range(1,10) list2 = range(1,10) list3 = range(1,10)   I want to create an list of tuples containing an assortment of each of the values in my three lists. Essentially I want an output such as:  combo = [(1,1,1), (1,1,2), (1,1,3) ... (1,4,2), (1,4,3) ... (4,5,4), (4,5,5) ... (10,10,9), (10,10,10)]   It seems like such as simple problem, but I don't know where to start.


Rails Ruby easiest way to get table names of my database

I'm trying to iterate through every table in my database.  I've found this answer from 9 years ago:    With the answer apparently being:  Dir[Rails.root.join('app/models/*.rb').to_s].each do |filename|   klass = File.basename(filename, '.rb').camelize.constantize   next unless klass.ancestors.include?(ActiveRecord::Base)   next if klass.abstract_class?   # do something with klass end   The answer above is 9 years old but I can't find anything more recent. Is there an easier way for me to access this list? My end result is I want a list of every table in my database. I also have namespaced models so would need to make the above even uglier for it to work for me.  EDIT: As multiple users have pointed out models do not exist in my DB. My bad. As I said in my original post:     My end result is I want a list of every table in my database.


In Java, in the body of an interface, must methods and variables be declared as having public access? If so, what could be gained from declaring the interface access without the 'public' access modifier i.e. leaving access as the default access?  As an example, what could be gained from writing  interface DefaultAccess {   as opposed to  public interface PublicAccess {   ?


How long can you read files from a flash drive if kept in a cool, dark room?

Say you had some sensitive information that you didn't want to store on the internet, was incredibly important to you, and you didn't need to access very often either.  Think of a digital picture taken of your grandma days before her death or something... Very important stuff.  So you load the file to a flash drive, put it in a vault, and forget about it.  When should you re-visit the vault to back-up the data to a newer, futuristic flash drive or whatever they are using to store data with in the future.  What are the chances that the data will have dissappeared or the flash drive become unreadable in 5 years? 10 years? 25 years? 100 years?


Disprove $m!=100x^2+20x$ using an estimation for factorial.

$\newcommand{\floor}[1]{\lfloor #1 \rfloor}$ I have the equation $m!=100x^2+20x$ where $x$ and $m$ are real non-negative integers. I wish to disprove for when $m\geq20$ how can I do this? I had an idea that is based on ending digits. For example m! can be divided by $10^{\floor{\frac{m}{5}}-1}$ and still end in a $0$. I was wondering if one could put an argument for that the equation doesn't exist. Using iteration. For example if I substitute  $x$ with $10x_1+5$(other correct substitution is $10x_1+10$ one gets $m!/200=50x_1^2+51x_1+13$ then one can proof that $x_2$ ends in a $7$ so $\therefore$ I can substitute $ x_1$ for $10x_2+7.$ Can one prove the following equation doesn't equal possibly using a lower bound on the approximation of the factorial function.  My method $\sqrt{2\pi}m^{m+0.5}e^{-m}$is the lower bound for $m!$


>11GB free space, but it says 100% disk usage?

$ df -i /mnt/large_linux/ Filesystem       Inodes   IUsed    IFree IUse% Mounted on /dev/sda1      29376512 1035086 28341426    4% /mnt/large_linux $ df /mnt/large_linux/ Filesystem     1K-blocks      Used Available Use% Mounted on /dev/sda1      462509952 451315844         0 100% /mnt/large_linux $ sudo dumpe2fs /dev/sda1 | grep -i reserved dumpe2fs 1.42.12 (29-Aug-2014) Reserved block count:     5875200 Reserved GDT blocks:      995 Reserved blocks uid:      0 (user root) Reserved blocks gid:      0 (group root)   Reserved GDT blocks at 30-1024   Reserved GDT blocks at 32798-33792   Reserved GDT blocks at 98334-99328   Reserved GDT blocks at 163870-164864   Reserved GDT blocks at 229406-230400   Reserved GDT blocks at 294942-295936   Reserved GDT blocks at 819230-820224   Reserved GDT blocks at 884766-885760   Reserved GDT blocks at 1605662-1606656   Reserved GDT blocks at 2654238-2655232   Reserved GDT blocks at 4096030-4097024   Reserved GDT blocks at 7962654-7963648   Reserved GDT blocks at 11239454-11240448   Reserved GDT blocks at 20480030-20481024   Reserved GDT blocks at 23887902-23888896   Reserved GDT blocks at 71663646-71664640   Reserved GDT blocks at 78675998-78676992   Reserved GDT blocks at 102400030-102401024   However I have plenty of free space:  $ pydf -k Filesystem      Size      Used    Avail Use%         Mounted on                 [omitted] /dev/sda1  462509952 451315844 11177724 97.6 [#####] /mnt/large_linux      I've also tried running sudo tune2fs -m 0 /dev/sda1, to no avail.


Can I smoothly upgrade from one LTS to next LTS release?

Question is about Ubuntu release process. Are migrations from n to n+1 releases expected?  Assuming we have server with installed Ubuntu 14.04 LTS. Will it be smoothly upgradable to Ubuntu 16.04 LTS via apt-get upgrade ?  Assumptions:   scope is software therefore we assume that given hardware is supported on both releases (upgrading from and to) that's why, always before upgrade you are asked to make backup to be able to revert in case of failure


What gifts would be welcome for a Swedish host family?

What are good gifts to take to Swedish family in 2014?  Many American things are now easy to find there.  The most recent postings seem to be 2012. Some say towels...terrycloth?  We'd like to get something for their little girl, too (about 2).


Why Tommen was called "First of his name" even if there has been a Tomen II Lannister?

Why Tommen is called "first of his name" while there has been a ?


Prove that $\frac{1}{a+1}<\ln \frac{a+1}{a}<\frac{1}{a},a>0$  First inequality using MVT:  $\frac{1}{a+1}<\ln \frac{a+1}{a}:$  $f(a)=\frac{1}{a+1}-\ln \frac{a+1}{a}$  $f(1)=\frac{1-2\ln 2}{2},f^{'}(a)=\frac{1}{a(a+1)^2}>f(1)\Rightarrow f(a)>f(1)$  $\frac{1}{a+1}-\ln \frac{a+1}{a}-\frac{1-2\ln 2}{2}>0$  This is not the starting inequality.   Is there something wrong in this method?


How to best determine if a bike will fit without riding it

I would like to get a Surly Cross-Check but the local bike shop doesn't stock them. They have suggested a 56cm, but I am concerned about the top tube length (I am more legs than torso). Are there proven ways to figure out whether a bike fits other than riding it?


Stripping shortcode from custom excerpt function

I'm using the following function to create a custom excerpt for my homepage and categories pages so I can do it by character count and have a custom "read more". However, I have captions shortcode showing up in my excerpt.  Example: [caption id="attachment_4656" align="aligncenter" width="450"] Crispy Vegetable Tacos[/caption] Do you sometimes feel overwhelmed when trying to decide what to make for dinner? What I’ve learned from my years as a family dinner planning expert ... continue reading  I tried adding line 5 to strip out the actual shortcode code but it isn't working. Am I on the right track? I'd prefer the shortcodes not to show at all and I've used the function I've seen on the 'net but it isn't working (I'm guessing cause I'm using a custom excerpt function). Anyone want to help me out, please? function get_excerpt($count){    $permalink = get_permalink($post->ID);    $excerpt = get_the_content();    $excerpt = strip_tags($excerpt);    $excerpt = str_replace(']]>', ']]>', $excerpt);    $excerpt = substr($excerpt, 0, $count);    $excerpt = substr($excerpt, 0, strripos($excerpt, " "));    $excerpt = $excerpt.' ... continue reading ';    return $excerpt; }  The fifth line I attempted to convert from this: $content = str_replace(']]>', ']]>', $content);  TIA!


package chemnum incompatible with [T1]{fontenc}?

If I use the fontenc package, I do not see compound numbers in the scheme:   \documentclass{report} \usepackage[T1]{fontenc} \usepackage{graphicx} \usepackage[crop=off]{auto-pst-pdf} \usepackage{chemnum} %\setchemnum{replace-style=,format=}  \begin{document} \replacecmpd{a} \replacecmpd{b} \includegraphics{test.eps}  See compound \cmpd{a} and \cmpd{b}. \end{document}   Output:    If I comment out the fontenc package, it seems to work:


I recently got a laptop (XPS 15) with 3200 * 1800 screen.  After updating drivers, Chrome looks like:   The tabs won't fill the red part of the screen.  I tried the follows in about:flags with no luck:   Enabled HiDPI setting - resulted in a very bad layout. Enabled Stacked Tabs - resulted in the above picture, tabs stacked but not fitting whole width. Played with touch screen options, no luck, context menu made larger, so does the tabs but still not fitting whole width. (Touch Optimized UI and Enable touch event) Reseting to factory default - no luck. Changed the Let me choose one scaling level for all my displays which was suggested in the duplicated question with no luck.   Any idea how to make tabs fit whole bar ?  EDIT: Using Windows 8.1


Why we don't add "s" to the verb in this sentence?

I came across this question in one of the English standardize tests in my country: It is required that the new student _____ in an extra English conversation course.  enroll enrolled will enroll would enroll is enrolling  The suggested key states that the answer is 1. enroll From my understanding, that choice is correct because we supposed to use present simple tense when stating such factual information. However, why wouldn't it be enrolls since the subject of the verb is new student which is a singular noun? Or that choice is correct because of any other reason or grammar rules?


Responding to planeswalker with doubling season in play

If I had  in play, then I cast any planeswalker, would my opponent be able to destroy it with  or exile it with  before I am able to activate any of its loyalty abilities?  I know the way priority typically works: you can activate the ability first, but since doubling season is a trigger, I am curious if my opponent could cast an instant while it is on the stack or if the planeswalker would be doubled as it entered, and then my opponent could not respond before I am able to activate it.


Strictly diagonally dominant matrices are non singular

I try to find a good proof for invertibility of strictly diagonally dominant matrices (defined by $|m_{ii}|>\sum_{j\ne i}|m_{ij}|$).  There is a proof of this in  but I'm wondering whether there are are better proof such as using determinant, etc to show that the matrix is non singular.


Drupal unexpected "Fatal error: Class name must be a valid object or a string [...] common.inc" on every page

"Fatal error: Class name must be a valid object or a string in C:\xampp\htdocs\uc\includes\common.inc on line 7506"  The error above showed up unexpectedly. I was adding a "Long text" field to a content-type, but when I expected to be brought to a saved field configuration page, I instead got a Fatal error on every page.  I had a look at includes\common.inc:  /**  * Get the entity controller class for an entity type.  */ function entity_get_controller($entity_type) {   $controllers = &drupal_static(__FUNCTION__, array());   if (!isset($controllers[$entity_type])) {     $type_info = entity_get_info($entity_type);     $class = $type_info['controller class'];     $controllers[$entity_type] = new $class($entity_type); // Line 7506   }   return $controllers[$entity_type]; }   However, I just don't understand Drupal at a low enough level to understand the relationships between these variables and functions.  I also searched Drupal for people with a similar problem:  (1)  who claims that I have to install the submodule "Relation Endpoints Field", but searching Drupal, .  (2) :  DELETE FROM cache; DELETE FROM cache_filter; DELETE FROM cache_menu; DELETE FROM cache_page; DELETE FROM watchdog;   (via , misleading name, I know.)  Clearing those tables from the cache did not help.  (3) And another user . Because I can't find a module specifically pertaining to old search facets, I went into MySQL system table, and marked the Search module's line with a 0 status, indicating to stop loading the module altogether.  On that same link as (3), one user suggested enabling the , so I dropped all the tables, imported the latest stable .sql, and installed the module, but after recreating the problem (trying to add a field to a content-type), that as well concluded fruitless.  Still, the problem remains  The Fatal error shows up on every page, making the site completely non-functional. Any help or direction would be immensely appreciated. Thank you for looking.


How to print in color using python print. For example  print('This should be red') print('This should be green')   Now everything is white text on black background. I use ubuntu, if it helps.


How do I Inherit the CSS Theme Color in my Sharepoint 2013 App?

I am building a Sharepoint 2013 App in Javascript / HTML / CSS and I want to implement / inherit the color / class / css used by the theme.  How do I do this?  I want to ensure consistency through usage of the same colors.  Thanks in advance!


I'm in the process of thesis writing. I'm LaTeX newbie and have its limited knowledge and experience. I'm thinking to use LaTeX or LyX for my thesis. Which one is better for thesis write up? If I go with LaTeX then how can I use it more efficiently. In case of LaTeX I'd like to have separate .tex file for each chapter and each chapter will have its own bibliography. Then how can I combine all chapters and other issue would of cross references. I have to my Univ. template for thesis write up. I'd highly appreciate if someone provide me general guidelines to manage and write a long document like thesis in LaTeX.


Copy directory from "Get Info" in Yosemite?

I am a programmer who used to constantly copy directory of a file from its "Get Info" menu. Since Yosemite, the original pure path is replaced with a "user-friendly" kid-version directory, which cannot be copied. Like this.    Is there a workaround for this?


I am using shortcut Ctrl+Alt+T for opening a new Terminal window. I am using one of the terminal very often (calculator and simple commands) and I want to set up another shortcut (like Ctrl+Alt+R or any other, I don't care) to switch to this specific terminal window (using gnome-terminal in Unity, Ubuntu 12.04).  Is this possible (and how)?


Is there a way to view a class and it's body code through the python shell?

As the question states, I want to know if it's possible to view the code (doc string) to view it's content and know how it is written/formatted. It doesn't have to necessarily be via the python shell, but it would be good if it was.  More specifically, how would I view a class code from a library? I've recently been messing around with a game-making library called pygame, I have came across this question when I was messing around with some modules, and did a "print (pygame.x.__doc__)" and much to my amusement it actually returned me with a code snippet. Hence the spark in curiosity.


I have tried just dropping the files but its not booting so how can I put the iso on the usb and its bootable to where it works. UNETBOOTIN DID NOT WORK FOR ME.


Redirecting logged in and non logged in users

I'm trying to redirect in different jsp page logged in user for example "Admin" and in a different view a non logged in user. Here is my method till now...  @RequestMapping(value = "/lidhOfruesKerkues", method = RequestMethod.POST)     public ModelAndView lidhOfruesKerkues(@ModelAttribute("merrPersiperKerkues") Kerkues k, Ofrues ofrues,             Authentication authResult) {         ofruesService.addOfrues(ofrues);         int kerkuesId = k.getKerkuesId();         ofruesService.matchOfruesKerkues(kerkuesId);         String role = authResult.getAuthorities().toString();         if (role.contains("ROLE_ADMIN")) {             return new ModelAndView("redirect:/adminHome");         }          return new ModelAndView("redirect:/ofrojNdihmeView/getKerkuesAktiv");     }   Error thrown is java.lang.NullPointerException: null that comes from "role" when I'm as a non logged in user. If I am logged in as ADMIN it works and redirects me as it should. Thanks in advance.


What do you call the protruding square structures on the top of a tower?

Here's an example:    It's not a tower but the structure is exactly the same. I'm referring to the four 'tooth-like' juttings on top of the tower structure attached on the left of that bridge. What do you call them (I'm looking for a common word)?


How to pull SOQL-query out of the loop in the trigger

Hello) I need to create a trigger that will record the number of reviews and the average rating from custom object (Review__c) in the corresponding fields on other custom object (Job_Applications__c). The trigger works, but throws an exception when testing to insert a large number of records (LimitException: Too many SOQL queries: 101). I understand this is because of my query in a loop. How can I pull SOQL-query out of the loop? trigger ReviewSetRatingTrigger on Review__c (after insert, after update) { List<Job_Application__c> updList = new List<Job_Application__c>();  List<Review__c> newList = new List<Review__c>([     SELECT Id, Rate__c, Job_Application__r.Id, Job_Application__r.Reviews_Count__c, Job_Application__r.Average_Rate__c     FROM Review__c     WHERE Id IN : Trigger.new ]);  for(Review__c rev : newList) {     List<Review__c> tempList = new List<Review__c>([ //Find reviews count and their summ         SELECT Rate__c         FROM Review__c          WHERE Job_Application__r.Id =: rev.Job_Application__r.Id     ]);     Integer revCount = 0;     Decimal rateSum = 0;     for(Review__c upd : tempList) {         revCount++;         rateSum += upd.Rate__c;     }      if(rev.Job_Application__r.Average_Rate__c == null) {         rev.Job_Application__r.Average_Rate__c = rev.Rate__c;         rev.Job_Application__r.Reviews_Count__c = 1;     } else {         rev.Job_Application__r.Average_Rate__c = rateSum / revCount;         rev.Job_Application__r.Reviews_Count__c = (Trigger.isInsert)? rev.Job_Application__r.Reviews_Count__c + 1 : tempList.size();     }         updList.add(rev.Job_Application__r);      System.debug(rev.Job_Application__r); }   update updList;  }


Extended Euclidean Algorithm: backward vs. forward

I'm confused about how to do the extended algorithm. For example, here's the gcd part gcd(8000,7001)  $$\begin{align}8000 &= 7001\cdot1 + 999\\ 7001&=999\cdot 7+8\\ 999&=8\cdot 124+7\\ 8&=7\cdot 1+1\\ 7&=1\cdot 7+0\\ \gcd(8000,7001)&=1\end{align}$$    Now, the extended algorithm  $$\begin{align}1 &= 8 - 1\cdot7\\ &= 8 - 1\cdot(999 - 8\cdot124)\\ &= -1\cdot999 + 8\cdot125\end{align}$$  How do you get this 8*125 from the previous line?


Every nonzero element in a finite ring is either a unit or a zero divisor

Let $R$ be a finite ring with unity. Prove that every nonzero element of $R$ is either a unit or a zero-divisor.


Openlayers 3 - Zoom to Selected Feature (Polygon)

I have an ol.source.ServerVector with several polygons drawn as features.  I'd like for the map to zoom to the extent of the selected polygon upon selection, but I'm hitting a wall.  I was able to find this post that helped with zooming to all of the features in the source, but not the selected feature specifically    var extent = source.getExtent(); map.getView().fitExtent(extent,map.getSize());   That works great to zoom to all of my polygons, but I can't seem to find any way to only use the selected feature's extent.


Proof that the One-Dimensional Simple Harmonic Oscillator is Non-Degenerate?

The standard treatment of the one-dimensional  (SHO) using the raising and lowering operators arrives at the countable basis of eigenstates $\{\vert n \rangle\}_{n = 0}^{\infty}$ each with corresponding eigenvalue $E_n = \omega \left(n + \frac{1}{2}\right)$. Refer to this construction as the abstract solution.  How does the abstract solution also prove uniqueness? Why is there only one unique sequence of countable eigenstates? In particular, can one prove the state $\vert 0\rangle$ is the unique ground state without resorting to coordinate representation? (It would then follow that the set $\{\vert n \rangle\}_{n = 0}^{\infty}$ is also unique.)  The uniqueness condition is obvious if one solves the problem in coordinate representation since then one works in the realm of differential equations where uniqueness theorems abound. Most textbooks ignore this detail (especially since they often solve the problem both in coordinate representation and abstractly), however I have found two exceptions:   Shankar appeals to a theorem which proves one-dimensional systems are non-degenerate, however this is unsatisfactory for two reasons:   Not every one-dimensional system is non-degenerate, however a general result can be proven for a large class of potentials (the SHO potential is in such a class). The proof requires a departure from the abstract solution since it classifies the potentials according to their functional properties.  Griffiths addresses this concern in a footnote stating that the equation $a \vert 0\rangle = 0$ uniquely determines the state $\vert 0\rangle$. Perhaps this follows from the abstract solution, however I do not see how.


I'm trying to find the center of $\mathbb{M}_n(K)$ with $K$ a field. I know what the center would be if $K$ was a ring, but I think this isn't the same for a field $K$. In particular I'm trying to find $Z(\mathbb{M}_2(\mathbb{F}_2))$.


Can you take the Attack action when not in range of an enemy?

Can you take the Attack action without attacking, just to get any side benefits?  For example, Blade Flourish says:     Whenever you take the Attack action on your turn, your walking speed increases by 10 feet until the end of the turn [...]   In all examples the bard has a speed of 30 feet and does not have Extra Attack.  First relevant scenario:     The Bard and the enemy is 40 ft apart. If the Bard can take Attack action before spending all 30 ft movement, then he can reach the enemy and attack them with the added extra movement. If not, the Bard and the enemy are now 10 ft apart.   Second relevant scenario:     There is an enemy around the corner. The Bard might or might not know there is an enemy there. With the added movement from Blade Flourish, he will be able to walk around the corner and attack the enemy.   Third relevant scenario:     Same as second scenario, but he will only be able to walk around the corner without being able to attack. He does not know if he can reach to attack the enemy at the end of the turn.   Is taking Attack action allowed without being able to make an attack?


I want to show that the sequence $a_n(t)=\frac{1}{n}\textbf{1}_{[0,n)}(t)$ does not converge in $L^1(\lambda)$. $u_n$ converges in $L^p$ implies $u_n$ is Cauchy so I want to use the contrapositive.  $$\begin{align}||a_{2n}-a_n||_1&=\int|a_{2n}-a_n|~d(\lambda)\\&=\int\left|\frac{1}{2n}\textbf{1}_{[0,2n)}(t)-\frac{1}{n}\textbf{1}_{[0,n)}(t)\right|~d(\lambda)\\&=\int\left|\frac{1}{n}\left(\frac{1}{2}\textbf{1}_{[0,2n)}(t)-\textbf{1}_{[0,n)}(t)\right)\right|~d(\lambda) \end{align} $$  not sure how to continue   I know the sequence does not converge. I want to prove it doesn't; this is why the question isn't a duplicate.


Scanf Dont scan char 2nd time while in a loop, any ideas?

n=10;     for(i=1;i<n;i++){         random = 1 + rand() % 3;           printf("\n\nIzdari savu izveli ==>");         scanf("%c", &zime);         if( zime=='a' )             printf("\nTu uzliki AKMENI");         else if( zime=='s' )             printf("\nTu uzliki SKERES");          else if( zime=='p' )             printf("\nTu uzliki PAPIRU");          if( random==1 )             printf("\nDators uzlika AKMENI");         else if( random==2 )             printf("\nDators uzlika SKERES");         else if( random==3 )             printf("\nDators uzlika PAPIRU");          if( random==1&&zime=='a' || random==2 && zime=='s' || random==3 && zime=='p')         printf("\n\nNeizskirts!!!");     else if( random==1&&zime=='p' || random==2&&zime=='a' || random==3&&zime=='s' )         printf("\n\nTu Uzvareji!!!");     else if( random==1&&zime=='s' || random==2&&zime=='p' || random==3&&zime=='a' )         printf("\n\nTu Zaudeji!!!");     getch();     }   Why when loop starts 2nd time it just skips scanf, and jumps to if( random==1 ),  and then jumps back to scanf and let u scanf a char?  Output looks like    It is just rock paper scizors game, but in other language.


help proving an binomial identity about catalan numbers

I need help proving the following identity:  $$\sum_{k=0}^n \frac{1}{k+1} \binom{2k}{k} \binom{2n-2k}{n-k} = \binom{2n+1}{n}.$$  It has to do with the Catalan numbers and Dyck walks. Notice that $$\frac{1}{k+1} \binom{2k}{k}$$ is the Catalan number $C_k$.


Find the necessity and sufficiency condition for $Z_m$ to be a Field

If we have a group like $Z_m =   \{0,1,2,...,m-1 \}$ and define an addition and multiplication on this group as the remainder of ordinary addition and multiplication division by $m$ (modulo m), prove that the necessity and sufficiency condition for $Z_m$ to be a Field is that the $m$ be a prime number!  e.g.: $$m=5$$ $$2\oplus4=1$$ $$2\otimes4=3$$  for $$m=2$$ I guess it's like Boolean algebra!


I've got a database with 3 Filegroups and each filegroups own a single file, Filegroup names are Primary, SecondFG and ThirdFG. I want to backup ThirdFG separately each time without backing up the others. I've tried it in many ways but when I want to restore database filegroup backup I get the error for other Filegroups or files are not included in the backup file! but When I backup all FileGroups together there would be no problem, please guide me how to backup and restore single filegroup, by the way I've read all BOL and I couldn't solve my problem!


In the early Action and Superman volumes, Superman is described as "Leaping over skyscrapers", and similar such terms. He is also portrayed as running from place to place, which begs the question, if you can fly, why run? Apparently he could leap over skyscrapers, but long distance air travel was something else again. The old TV show also began with "Able to leap tall buildings in a single bound".   Seems from all this that Superman didn't really "fly" - i.e. he had no scheme to give him lift, or any sort of propulsion system - he just made very long, strong (strong enough to reach escape velocity from the earth and much larger worlds as well), high jumps, and was able to navigate using aerodynamic principles - similar to a flying squirrel or fish, as opposed to a bird or bat.   Even though later on we find that he did travel long distances by air, couldn't we explain all of Superman's maneuvers as extraordinary powerful and carefully calculated leaps and bounces?  The proof would be from situations where he demonstrates acceleration without a boost from some external source of energy: If it's all leaping, even if it's incredibly powerful, he would be constantly decelerating to some extent.  Is there any proof that he could actually fly using some sort of propulsion system, like an airplane or a bird, and not just engage in mighty, calculated leaps? Would constraining Superman's ability to jump (hard to imagine how...) result in him not being able to "fly"?  This question is definitely not a duplicate. I am not asking how he flies, I am asking if he actually flies. See accepted answer, from before this question was mistakenly closed.


nullpointer execption on samsung Galaxy note3

I brought some interesting problem.  It is about Nullpointer exception and it is only occur at specific phone, Samsung Galaxy Note3-5.1.0. Since I didn't checked all the other phones, however, running on genymotion-samasung-galaxyS5-4.4.4 was fine.  The code is following.  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);     final LinearLayout btn_search = (LinearLayout) findViewById(R.id.searchBtn);     final LinearLayout btn_mypage = (LinearLayout) findViewById(R.id.mypageBtn);     final LinearLayout btn_map = (LinearLayout) findViewById(R.id.mapBtn);     Log.d("NULLPOINTER",": " + btn_search + " " + btn_map + " " + btn_mypage);  }   Then, the log is like,  D/NULLPOINTER: : null android.widget.LinearLayout{2ae0be1a V.E..... ......I. 0,0-0,0 #7f0e007d app:id/mapBtn} android.widget.LinearLayout{1db90d4b V.E...C. ......I. 0,0-0,0 #7f0e007e app:id/mypageBtn}   I checked all the R.id.*** and layout and since they are implemented in same way, I don't know what is the problem. Strangely, only the first one, which was lastly added is always null. However, on the other phones I can get the object well.  Do you know any idea?


What's this camera viewport/clipping visualization for and how do I get rid of it?

In Wireframe and Solid view modes, there's this "cone" of visibility that extends out from one of the cameras and clips all the objects in the scene:  It does not move at all when I switch cameras or move the camera. I've tried clearing the camera border but it had no effect. It doesn't appear in Material Preview or Rendered modes. How did this show up, and how can I make it go away?


NoScript: is it possible to temporarily allow JS from some domain only on a selected site?

For instance, when I come to site superuser.com, I would like to temporarily allow ajax.googleapis.com - but just on this site, not anywhere else.  I know this can be done permanently (), but I would like these permissions to be temporary. Can this be done?


It is apparent that kills gives you experience that gain you promotion for your normal abilities. How does it work for Psi-abilities? What grants experience/promotion points for Psi-ability promotions?


I have a 237MB /boot partition which I thought should be enough for normal operation, however, when I do a apt-get upgrade I get the following:  $ sudo apt-get upgrade [sudo] password for ron:  Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... The following packages were automatically installed and are no longer required:   linux-headers-4.2.0-16 linux-headers-4.2.0-16-generic linux-headers-4.2.0-27   linux-headers-4.2.0-27-generic linux-image-4.2.0-16-generic   linux-image-4.2.0-27-generic linux-image-extra-4.2.0-16-generic   linux-image-extra-4.2.0-27-generic linux-signed-image-4.2.0-27-generic Use 'apt-get autoremove' to remove them. Done 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]  Setting up initramfs-tools (0.120ubuntu6) ... update-initramfs: deferring update (trigger activated) Processing triggers for initramfs-tools (0.120ubuntu6) ... update-initramfs: Generating /boot/initrd.img-4.2.0-34-generic  gzip: stdout: No space left on device E: mkinitramfs failure cpio 141 gzip 1 update-initramfs: failed for /boot/initrd.img-4.2.0-34-generic with 1. dpkg: error processing package initramfs-tools (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  initramfs-tools E: Sub-process /usr/bin/dpkg returned an error code (1) $   and that while:  $ df -h Filesystem      Size  Used Avail Use% Mounted on udev            1.9G     0  1.9G   0% /dev tmpfs           384M  6.2M  378M   2% /run /dev/dm-0       454G  9.8G  421G   3% / tmpfs           1.9G     0  1.9G   0% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs           1.9G     0  1.9G   0% /sys/fs/cgroup /dev/sda2       237M  209M   16M  93% /boot /dev/sda1       511M  3.4M  508M   1% /boot/efi tmpfs           384M  8.0K  384M   1% /run/user/1000 $


MainActivity throwing null pointer exception in android studio

MainActivity  com.example.vivek.settleup; import android.support.v4.widget.DrawerLayout; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.Menu; import android.view.MenuInflater; import android.view.View; import android.widget.Toast;  public class MainActivity extends AppCompatActivity {     Toolbar toolbar; DrawerLayout drawerLayout; private static final String log = "myLogg"; @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     toolbar = (Toolbar) findViewById(R.id.toolbar);     setSupportActionBar(toolbar);     drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);     toolbar.setTitle("Home");     getSupportActionBar().setTitle("Home");     toolbar.setNavigationIcon(R.drawable.ic_action_name);     toolbar.setNavigationContentDescription("Navigation Icon");     getSupportActionBar().setDisplayShowHomeEnabled(true);     toolbar.setNavigationOnClickListener(             new View.OnClickListener() {                 @Override                 public void onClick(View v) {                 Toast.makeText(MainActivity.this,"touched",Toast.LENGTH_LONG).show();             }         }      );      NavigationDrawerFragment1 drawerFragment = (NavigationDrawerFragment1) getSupportFragmentManager().             findFragmentById(R.id.fragment);             drawerFragment.setUp(drawerLayout,toolbar); /**this call is throwing nullpointer exception**/    }    @Override   public boolean onCreateOptionsMenu(Menu menu) {       MenuInflater inflater = getMenuInflater();       inflater.inflate(R.menu.main,menu);       return super.onCreateOptionsMenu(menu);   } }   NavigationDrawerFragment1  package com.example.vivek.settleup; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.widget.DrawerLayout; import android.support.v7.app.ActionBarDrawerToggle; import android.support.v7.widget.Toolbar; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup;   /**  * A simple {@link Fragment} subclass.  */ public class NavigationDrawerFragment1 extends Fragment {     DrawerLayout mDrawerLayout;     ActionBarDrawerToggle mDrawerToggle;     private static final String log = "myLog";      public NavigationDrawerFragment1() {         // Required empty public constructor     }      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container,                              Bundle savedInstanceState) {         // Inflate the layout for this fragment         return inflater.inflate(R.layout.fragment_navigation_drawer_fragment1, container, false);     }      public void setUp(DrawerLayout drawerLayout, Toolbar toolbar) {         mDrawerLayout = drawerLayout;         mDrawerToggle = new ActionBarDrawerToggle(getActivity(),drawerLayout,toolbar,                 R.string.drawer_open,R.string.drawer_close){              @Override             public void onDrawerOpened(View drawerView) {                 super.onDrawerOpened(drawerView);             }              @Override             public void onDrawerClosed(View drawerView) {                 super.onDrawerClosed(drawerView);             }         };         mDrawerLayout.addDrawerListener(mDrawerToggle);     }     }


All models of $\mathsf{ZFC}$ between $V$ and $V[G]$ are generic extensions of $V$

I'm reading the proof of lemma 15.43 of Jech's Set Theory:     Let $G$ be generic on a complete Boolean algebra $B$. If $M$ is a model of $\mathsf{ZFC}$ such that $V\subset M\subset V[G]$, then there exists a complete subalgebra $D\subset B$ such that $M=V[D\cap G]$.   In the proof of this theorem the author states the following fact: "First we note that since $M$ satisfies the Axiom of Choice, there is for every $X\in M$ a set of ordinals $A_X\in M$ such that $X\in V[A_X].$"  My question is, why is this fact true?  Thanks


How much are Cricket Umpires paid in India starting from Club level to Ranji, Duleep trophy, etc.?

EDIT: The question  does not answer my question. It does not address the TIME required for an umpire required to reach national level from local level.  Specifically, after officiating local matches, how much time does a state association take to send one's name to BCCI for level 1 exam?  Adding to the question, also how much time does it take for one to reach Ranji level from club level?


Script file is created to send junk mails

I have installed Joomla 3.3.6 on my ubnutu server 15.04 on cloud. I have noticed some script file created automatically which is sending some junk mail randomly. I have installed maldetect to check for malware.   Recent file detect was /var/www/html/joomla-test/libraries/joomla/observable/ini3.php  I have deleted this file now. But this type of script file created frequently. How to find from where this file created and delete permanently.  Do I need to move code to different server to get rid of this?.  Edit:  It is related to Joomla plugins I suspect. If we move our code to new server or install joomla again and install all necessary plugins and theme again same script might be created again.


How to securely erase solid state drive in netbook running ubuntu

I want to sell (or donate) my HP Mini 1000 netbook, but I am concerned about identity theft and securing personal information with the transition to a new user.   I am running Ubuntu 12.04 LTS. The netbook has a 16 GB solid state drive. I am under the impression that different methods are required to securely erase an SSD, compared to a traditional hard drive.  How do I do this and prepare this computer for sale (or donation)? It is not important whether the computer can still boot the operating system after this erase - only that an operating system can again be installed.  I have tried to read about this in many places on the web, including in askubuntu, but the process is never explained in sufficiently clear, jargon-free language. Or perhaps it is, but I still don't understand how to do this! Can I do this without procuring software? If I need to get software, what should I get?   Essentially, can anyone explain how I do this to someone who, you can assume, knows very little about computers, but can competently follow directions?  Thanks in advance!


how i can put an image over image? for e.g. a social image over header image.  code:

      i want to put it on the top-left.. any idea? background-image is a wrong idea, because my silder script uses divs and images..


How to convey LWC's complex Reactive property back to markup?

From SF :      There are some limitations on the depth of changes tracked for   rerendering in reactive properties. The tracking depth depends on the   type of the reactive property.      Lightning Web Components tracks changes to the internal values of   these types of reactive properties:         Primitive values    Plain objects created with {…}   Arrays created with []         Also SF does not track for complex types like Date.   Now what I wanna do is track an Array of complex object. If a new element is added subtracted from the array re-render the UI. Classic Data - table example.  So I declared my Markup:  <template>     <h1>Hello </h1>     <lightning-datatable                 key-field="id"                 data={data}                 columns={columns}                 is-loading={tableLoadingState}>             </lightning-datatable>              <lightning-button variant="brand" label="Add row" title="Add row" onclick={addRow} class="slds-m-left_x-small"></lightning-button> </template>   JS:  import { LightningElement, track } from 'lwc'; const columns = [     { label: 'Label', fieldName: 'name', type:"text"},     { label: 'Website', fieldName: 'website', type: 'text' },     { label: 'Phone', fieldName: 'phone', type: 'text'  } ]; export default class App extends LightningElement {     @track data = [{name:'Mylabel' , website:'google.com' ,phone :'74126478963',amount : 45  }];     @track columns = columns;     @track tableLoadingState = false;      addRow(){         console.log('add row called');         this.data.push({name:'Mylabel2s' , website:'2google.com' ,phone :'74126478963',amount : 45 });         console.log(JSON.stringify(this.data));         //this.data =[];      }   }   When I save and try running this I get the message as shown in docs.  [LWC warning]: Property "_def" of [object:vm undefined (0)] is set to a non-trackable object, which means changes into that object cannot be observed. <lightning-primitive-header-factory>   which means I cannot track the row data for lightning-datatable, which also means when I add or remove rows I would be unsuccessful.  I could not find a solution to add row in datatable and get it updated back in the markup, I searched dev guide and recipe book. Is this a limitation? or there is a workaround?


How to deal with abbreviations at the end of a question?

In a sentence like     Should we host them on imgur et cetera?   where I want to abbreviate the "et cetera", what is the correct punctuation? Using a period after the "etc." like mid sentence usages seems wrong as it looks like a full stop when I read it.     Should we host them on imgur etc.?   Or is this the correct usage?


row rank= column rank, alternative proof

I am studying the theorem that states that the row rank of a matrix is the same as the column rank. I understood the proof and managed to use it in specific examples using a matrix.   I am now, trying to find an informal proof/explanation about the fact that row rank=columns rank but I am not sure what is suppose to do by given an informal proof or explanation.  Can anyone help me on this or show me where can I find more about this topic?   Thanks


In the log-log regression case,  $$\log(Y) = B_0 + B_1 \log(X) + U \>,$$  can you show $B_1$ is the elasticity of $Y$ with respect to $X$, i.e., that $E_{yx} = \frac{dY}{dX}(\frac{Y}{X})$?


Lets say I have a  creature that says "Whenever another creature enters the battlefield under your control, you may gain 1 life." and I currently have all 4 of them in the battlefield. Then I cast another creature and : Do I get 1 or 4 life? Does that effect trigger for every priest or just once? thanks for help


Solving an exponential inequality problem

How do I prove the following inequality :  $$\Bigg(\frac{2}{\alpha^2} \, \big( e^{\alpha x} - e^{\alpha y} \big) \, + \, e^{\alpha y} (y^2 - x^2) \; \Bigg) > 0 $$  given, $x, y > 0$ ?  Can anyone provide me with hints about this problem ?  Thanks in advance.  Here, $\alpha$ is a positive constant.


Would I be allowed to get on a plane from the UK and fly to America with tea?

Today I was doing some research on food and drinks and realised that tea is not a very big thing in The U.S. and that all the "good" brands of tea are extremely overpriced or quite "unattractive".  So I thought I'd take a box (or two) with me to The U.S, but unfortunately the TSA might confiscate my tea and I may have to throw it away before I'm allowed to enter the country.  Would I be allowed to get on a plane from the UK and fly to The U.S. with tea? If not are there rules and regulations on shipping tea to The U.S. and would I be allowed to do it?  NOTE: when I say tea I mean Tea bags and Loose Leaf Tea.


Evaluate the following limit and find alpha and beta (given the limit exists):

Evaluate the following limit, assume that the limit exists and has a non zero finite value : $$\lim_{n\rightarrow\infty}\dfrac{\sqrt[{n}^{2}]{1!2!3!\cdots n!}}{{n}^{\alpha}}=\beta$$ Also find $\alpha$ and $\beta$. I have tried to solve this question by equating the limit to $L$ and taking log on both sides, but I am not able to understand how do I tackle with the $\sqrt[{n}^{2}]{x}$ part. Since this is of the $\frac{{\infty}^{0}}{\infty}$ form I am unable to use the $L'Hospital$ rule, please provide an approach for solving this problem directly or converting it into 0/0 or $\infty$/$\infty$ form.


How do I find a command if I don't know its name?

As a Unix beginner, I often find myself wanting to know the name of the command that achieves a particular function I'm after. How can I go about finding out the name of the command, given a description of what it does?


In a try-catch block, does "finally" override "return" in the exception block?

It seems like return is overridden by finally in a catch block. Is that correct? For example:     public String myMethod() {      try {         // Do stuff      } catch(Exception e) {         // Handle exception      return failed;      } finally {         // Close sockets     }      return success;     }   If I get an exception in the above code the method still returns success.


Python - How to ignore white spaces in double quotes while splitting a string?

I have my data as below   string = ' streptococcus 7120 "File  being  analysed" rd873 '   I tried to split the line using n=string.split() which gives the below result:  [streptococcus,7120,File,being,analysed,rd873]   I would  like to split the string ignoring white spaces in " "   # output expected :  [streptococcus,7120,File being analysed,rd873]


What does it mean if Community “asks” a question?

Just scrolling through Stack Overflow, and saw this:    I looked in and the author who asked it wasn’t Community. What does this mean? The real asker’s profile picture was gray.


Cannot upgrade from 19.4 to 20.4 since 19.4 is no longer supported

When I run sudo do-release-upgrade what I get is An upgrade from 'disco' to 'focal' is not supported with this tool. I have been looking here , but the solution says 'upgrade to 19.10 first'. That doesn't work since the command to upgrade is what is not working. The solution in  is also not working for the same reason. What is the way to go? Is it possible or should I forget about it an install a the 20.4 version from scratch and install everything again?


I have created vm instance in gcloud. And setup firewall rule to allow connection from port 5000.I added network tag to my vm instance.  But if i test the connection by teneting to port 5000 I get      telnet: Unable to connect to remote host: Connection refused   Content of netstat -lnp


I'm currently writing an import script/addon.  The file format is one vertex per line: x, y, z, u, v With 3 lines for each triangle (no quads).  So far I've got vertex's, edges and faces all importing correctly.  Now I just need to import the UV coordinates for each vertex.  However I'm having trouble trying to find a way to do this.  The best result so far was copying code from the UV operator template, which gave me a UV Map, but it puts the whole model at one point.


Show that $13$ divides $2^{70} + 3^{70}$.   My main problem here is trying to figure out how to separate the two elements in the sum, and then use Fermat's little theorem. So how can I separate the two?  Thanks!


Why does Stirred (rotating) coffee alters cup’s resonance frequency?

I place a spoon in my cup of (dolce gusto lungo) coffee and tap the bottom of the cup with my spoon.  It emits a certain (fixed) frequency.  However, if I stir the coffee (but not so fast that the surface of the coffee has any appreciable dip in the centre) and repeat the tapping in the centre with the spoon the frequency sounds lower initially but rises as the coffee stops rotating.  Curiously it appears to continue rising for a brief period after the coffee appears to have stopped rotating in the cup. What’s happening?  Is it related to the fact that if I stir the coffee fast enough then all the “froth” on the top of the coffee disappears (subsumed into the coffee?), but reappears as the rotation slows down. Other than stirring the coffee nothing is being added.


Why do physicist accept the idea of singularities?

I am currently reading though Peskin and Schroeder and have recently encountered the UV cutoff. Basically, when we encounter an infinity in QFT which is caused by integration over momentum or energy, we can disregard this by limiting our integral as we know our formula is not exact and it is absurd to think that it should work at arbitrary energy.  This got me thinking about singularities. Basically knowing that GR is a not quantum theory and that surely at such high energy density and small volumes as found in black holes, QM effects will become very important, why is it that we are fine saying everything collapses into a singularity rather then saying we don't know and that the formula is invalid at such ranges?


Minecraft Command Block keeps killing me

I was working on a build in a superflat world in Minecraft 1.14.2 but the slimes kept annoying me. I had forgotten that you can set it so that entities do not spawn, so I tried using a command block next to the build to keep killing slime blocks. I activated it, and the game instantly killed me, saying that I "fell out of the world." I cannot get back to my project without instantly being killed by the command block, and I really do not want to restart the project. I do not remember the coordinates of the block, and it kills me before I can even see it. Now I am in 1.14.3, and I thought that something would change, but it didn't. I tried using the command that nullifies command blocks, but it didn't work. I have gone through multiple posts of things like this happening, but nothing seems to work. Please help me!!!


I'm creating a druid and came across an interesting tactic that seems to be both overpowered and allowed as the rules are written. (Our characters will be level 5 due to people wanting to keep their previous characters from our last campaign.)  The scenario is this:    The party comes across a scary enemy.   The druid gets the highest initiative.    Druid casts "Conjure Animals" as a third level spell.   He decides he wants 8 Constrictor Snakes (or any other sized beasts that can grapple) to surround the enemy.    The initiative roll for the group of snakes allows them to act next.   The druid commands them to attack the target. (They obey any verbal commands that you issue to them, no action required.)    They all attack the target and grapple him. (Based on their action "constrict". Basically if they hit they deal damage and automatically grapple.)              This poses several questions:   Can multiple creatures grapple a single target?    Would this require multiple attempts to break free?     How would you deal with different creatures with different "break free from grapple" saves?      How would this apply to different beasts? (Constrictor Snakes, Crocodiles, Giant Crabs, Giant Octopi...)