Why must resistors be on the respective anode terminals instead of the common cathode terminal of a RGB LED?

Different from the best answer of this one:  But well, I'm also an electronics noob ^.^  Recently I bought the official Arduino starter kit and played around with the common cathode RGB LED that came with this kit. In the project book, the instructions for the colour mixing lamp is to use separate 220ohm resistor for each of the RGB legs. But I thought, why can't I put the resistor on just the cathode of the LED?   I tried that by plugging the LED into the breadboard and connecting the cathode through a 220ohm resistor to the ground of Arduino UNO. When I touched any one of the R, G or B anode legs with a jumper wire connected to +5V, the respective colour lights up alright. However, when I bridge the G and B pins together, only the green LED lights up. When I bridge all three anodes together, only the red LED lights up. But if I connect the anodes to +5V through their separate 220ohm resistors(according to the instruction), the colours will combine.   Why is it so?


If $ G $ has no non-trivial automorphism, then $ G $ is abelian and $ g^2 = e $ for all $ g \in G $ .  With the assumption, I dont know how to start the proof.  If there is no non-trivial automorphism, then there is only trivial automorpism, the identity morphism. But how can I show  $ g^2 = e $ for all $ g \in G $ with it?


I inherited some data that lines up correctly on the map, but in face are in different coordinate reference systems/SRID. Here is a screenshot example:    The CRS of the green layer is:   EPSG: 4326   The CRS of the purple layer is:  EPSG: 2264   They are lined up correctly on the map, but to do stuff in PostgreSQL/PostGIS with them, they need to be in the same CRS/SRID. If I change the CRS of the green layer to match the purple layer, naturally the green layer is now way off the map.  I could manually recreate the green layer, but this would be time consuming. Is there a better solution? Could I re-create the green layer as it is, but with a different CRS? Either using some tool in QGIS or in PostgreSQL/PostGIS?


The treasure table on page 138 is missing the die roll no.10.  Is there any errata for the DMG for that or even in general?


I'm using Maverick with Compiz enabled.  I've searched AskUbuntu and Google. AskUbuntu doesn't have anything on this topic and everything Google turns up is a couple years old.  I'm doing browser tests and my tests are constantly spawning new Firefox windows. The problem is, when the window is spawned it takes focus. This is incredibly annoying as I'm usually in the middle of typing somewhere else. This doesn't only happen with my tests, but is the most common example I run into. Sometimes my IDE decides it wants focus when something special happens (like when something is done compiling) and then later I'll find fragments of IM messages I've typed in my code. This is driving me crazy. I've looked in both Gnome settings and Compiz settings and can't find a way to prevent that from happening.  Does anyone know of a way to prevent an app from stealing focus when it is opened? I'd rather have the taskbar flash at me or something to get my attention.


Show that if $G$ is connected and it has two spanning trees with differente edges, then $G$ has a spanning graph eulerian

i need help with this:  Show that if $G$ is connected and it has two spanning trees with differente edges, then $G$ has a spanning subgraph eulerian  spanning tree: spanning subgraph of $G$ and it's a tree  I really need to solve it, can you give a clue, please? thansk!


Assigning multiple indices at once from one list

I have five user variables with different names. I'd like them to end up in an array, and am wondering if I can do the assignment to multiple array indices in a single line. Currently, if I do this  var users = {user5k, user10k, user15k, user20k, user25k};   I can't index it later (says users[0] is undefined). So I want the indices built in to the assignment. Something along these lines:  var users = {}; users[0:4] = {user5k, user10k, user15k, user20k, user25k};   This doesn't seem possible in JavaScript, meaning I have to do this:  var users = {}; users[0] = user5k; users[1] = user10; // ... et cetera   Is there a way to accomplish the first solution?


What I want to do is to set DATE_REACT a value when the first condition is satisfied, and a different value when the first condition is not satisfied. The problem is that the first condition is executed always, even when it shouldn't. What I am doing wrong?  UPDATE BILLS SET STATE = 2, DATE_REACT = CASE  WHEN (DATE_EM <= CURTIME() <= ADDTIME(DATE_EM, '00:02:00'))  THEN ADDTIME(CURTIME(), '00:13:00') ELSE ADDTIME(DATE_REACT, '00:13:00') END WHERE STATE = 1;


I just encountered this review and I'm unsure what to do with it. Somebody claimed the posted code to be copyrighted.      So should this edit be accepted just on the basis of this claim?  Should it be flagged for moderation?


I often start a long running command that is bound to either CPU, Disk, RAM or Internet connection. While that is running, I find that I want to run a similar command. Let's say downloading something big.  Then I start a shell with wget ...1 and let it run. I could open another shell and run the other wget ...2, but now they would fight for the bandwidth. When I just type the second command into the running shell, it will execute that later on, since wget is not interactive.  Is there a reasonable way to do this with either Bash or Fish Shell?


How to find which program is accessing the webcam through audiodg.exe?

A webcam's light has been intermittently coming on, and I'm trying to track down what program is accessing it (without just blindly killing programs until the light goes off).  I've gone through the standard steps: finding the "Physical Device Object" IDs in Device Manager, using Process Explorer to search open handles and which programs are accessing what, but this leads to "audiodg.exe" accessing the webcam handles, which is apparently the "Windows Audio Device Graph Isolation".   This is what's directly accessing the webcam, but I can't see what program called for its access in the first place, to see which program is pulling the puppet-strings, so to speak.  So is there a way to trace which program is accessing a webcam's microphone or video via "Windows Audio Device Graph Isolation", audiodg.exe?


Calculating the distance when shooting at a flying foe

Lets say that a foe is 30' away and 20' up in the air.   Using trigonometry, that gives a distance of 30^2 + 20^2 = 1300 sqrt(1300) = 36.06 ...but I don't believe Pathfinder expects folks to use trig to figure out range increments.  Is there a rule that covers this? I can't find it but my impression was that one actually just takes the larger of the two values (so if someone is 100' away and on one dimension and 50' away on another, it's still just a range of 100').


Is there a feature by which we can buy reputation on SO (e.g 100 rep for $1)?, or a bot by which we can hack and increase our reputation?


When to use 'the' in front of a country?

Citizens of the Lithuania, sounds wrong. Citizens of the Russia too. However, citizens of the Ukraine, sounds right. Also of the United States (of America) as well as of the United Kingdom.  What is the proper usage of 'the' to name a country?


Is there a complete map of all known places in Faerûn? Many of the top-level maps don't have all locations (Helm's hold next to Neverwinter), Phandalin, and generally all of the locations that are marked in the DM maps (that are not on the players maps) are also very hard to find (if you don't know in what adventure to look for) Is there a map with all known locations that either have an adventure taking place there or a dungeon or something similar? For clarification: I'm looking for a spoiler-heavy DM map with the hidden locations, not for a player map.


Reference for image drawn by yourself, but originated from others?

I am using some images (among others: Laser niveaus) in my thesis. I am drawing them myself with tikz, but as a guidance I use images and data from papers and books. Should I reference them, and if yes, how?


Is the following sentence grammatically correct?

The sentence I am unsure about is:     A rigid adherence to the doctrine of precedent would have resulted in   a country where segregation was lawful but minimum wages were not.   I'm confused by the subjunctive, and in particular the proper usages of 'was' and 'were'. Are they used properly above?


Why are hydrogen energy levels degenerate in $\ell$ and $m$?

Is there a good physical picture of why the energy levels in a hydrogen atom are independent of the angular momentum quantum number $\ell$ and $m$?


I'm working through an elementary number theory course right now and I think I've come up with a proof here but wanted some feedback on my logic.    Question:  If the sum of the digits in base 10 is divisible by 9, then the number itself is divisible by 9.    Proof: Suppose that $9|d_1+d_2+...+d_n$ then $d_1+d_2+...+d_n=0\mod9$  Now consider $d_1(10^{n-1})+d_2(10^{n-2})+...+d_{(n-1)}(10^1)+d_n(10^0)$ Each power of $10$ is equivalent to $1\mod9$   therefor  $d_1(10^{n-1})+d_2(10^{n-2})+...+d_{(n-1)}(10^1)+d_n(10^0)=(1\mod9)(d_1+d_2+...d_n)$  $9|(d_1+d_2+...d_n)$ by our assumption, thus $9|(1\mod9)(d_1+d_2+...d_n)$  Thus we have shown that if 9 divides the sum of the digits in base 10, 9 divides the number itself.    The only question I really have is whether I'm jumping the gun on my assumption concerning the powers of 10 being $1\mod 9$.  I think this is fair game here but not 100% confident.  Thanks.


Throughout the , we exclusively see human Empire officers, while the rebels’ staff seems to be composed from a large range of species. While a non-human rebel officer is only shown in the  (specifically ), I don't remember any non-human Empire officer. There is the notable exception of , but if I remember from the  (I read those about 15 years ago), it was stated that this was something unusual. There is also , who was not human, but it was before the Emperor's rise to power. Although "racist" is probably not the correct word, as it's the human versus non-humans species, was the Empire, and so the Emperor, racist?


I am not sure if my approach is on the right track for $\Rightarrow$, since I don't know how to proceed and reach the conclusion that $A$ meets each path-component of $X$? And I hope my approach to the other direction make sense?     $H_0(X,A) = 0 \iff A$ meets each path-component of $X$.   By Theorem 2.16, we have the exact sequence:  $$\cdots   H_0(A) \stackrel{i_*}{\to}  H_0(X) \stackrel{j_*}{\to}  H_0(X,A) \to 0$$  $\Rightarrow$: If $H_0(X, A) = 0$, then $H_0(X) = \ker j_*(H_0(X)) = \operatorname{Im}i_*(H_0(A))$. Because $H_0(X) = \operatorname{Im}i_*(H_0(A))$, we know $i_*$ is surjective.    Edit: I hope I figured this out?  The map $i_*: H_0(A) \to H_0(X)$ is surjective implies that the map $i_*: \bigoplus_\alpha H_0(A_\alpha) \to \bigoplus_\beta H_0(X_\beta)$ is surjective. That is to say that $\forall \beta, \exists A_\alpha : i(A_\alpha) \subset X_\beta$. Hence $A$ meets each path-component of $X$.    $\Leftarrow$: According to Proposition 2.7, for any space $X$, $H_0(X)$ is a direct sum of $\mathbb{Z}$'s, one for each path-component of $X$. So if $A$ meets each path-component of $X$, $H_0(X) = H_0(A) \approx \mathbb{Z}$. So the inclusion $i: A \to X$ induces a surjection $H_0(A) \to H_0(X)$.  So since $H_0(A) \to H_0(X)$ is surjective, $\operatorname{Im} i_*(H_0(X)) = H_0(X, A) = \ker H_0(X, A)$. Since the entire $H_0(X, A)$ lies in the kernel of $j_*$, $H_0(X, A) = 0$.


Change the Windows key to Caps Lock in Windows 7

I often use the Windows key in order to switch between workspaces. However, the Windows key is located in a rather uncomfortable position finger-wise, so I would like to change it to the Caps Lock key (which I never use anyway). How can I do this in Windows 7?


Comment out `lstinputlisting` without actually removing them

I am wondering is there a way to hide or comment out all lstinputlisting from latex without actually removing them.  My codes are all like this:  \lstinputlisting[language=Python, caption=NewHope implemented using SageMath]{code_snippets/LWE-KEX/NewHope.sage}   I tried to use comment package it  and also \renewcommand{\lstinputlisting}{}, both did not work.


I can't close questions on mobile right now.   The page just jumps to the top and nothing else happens.   (And what kind of quality standards are preventing me from asking this question?)


SSH into multiple machines and run multiple commands

Writing a script to ssh into multiple machines and running multiple commands. However once the ssh is successful I get the following from each host without a single commands executing, the for loop works fine and I am able to ssh successfully into all the machines.  Connection closed by host port 22  If I exclude the -tt flag in ssh I also get,  Pseudo-terminal will not be allocated because stdin is not a terminal.  How do I get the following script to execute successfully on the machines. Below is the script I am using for vm_ip in "${vm_ip_array[@]}" do  ssh -tt -i {$key_pair} {$username}@${vm_ip} << HERE  [do multiple stuff here like update packages and other maintainence stuff (sudo commands)]  exit  HERE  done  Additional Info : I run a few export statements as well, will that be causing an issue? Would it be recommended to have the multiple commands as a script on the individual machines? Updating the scripts this way is a nightmare though.


After migration of an old WP blog on my local web server I obtain white screen, why? is it a wp_options DB table problem?

I am pretty new in WP (I came from Joomla) and I am finding some difficulties in the migration of an old WP website (made inWP 3.5) on my local web server.  I have performed the following operation:   I have put the website backup into a directory named blog into my Apache www directory on my Ubuntu local system. Then I have put the database backup on my MySql local server Finally I have change the values in the wp-config.php file to use my local DB   The problem is that when I try to open the URL:  http://localhost/blog/   to see the website I see noting (a white screen)  Inside the wp-config.php I have activated the debug mode by the line:  define('WP_DEBUG', true);   and I have no errors, so I think that this is not a DB problem.  Inside the Apache error log file (/var/log/apache2/error.log) I found that the following errors occurs:  [Fri Jan 10 22:04:50 2014] [notice] Apache/2.2.22 (Ubuntu) PHP/5.3.10-1ubuntu3.9 with Suhosin-Patch configured -- resuming normal operations [Fri Jan 10 22:05:08 2014] [error] [client 127.0.0.1] PHP Warning:  require_once(/var/www/blog/wp-load.php): failed to open stream: No such file or directory in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:05:08 2014] [error] [client 127.0.0.1] PHP Fatal error:  require_once(): Failed opening required '/var/www/blog/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:37 2014] [error] [client 127.0.0.1] PHP Warning:  require_once(/var/www/blog/wp-load.php): failed to open stream: No such file or directory in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:37 2014] [error] [client 127.0.0.1] PHP Fatal error:  require_once(): Failed opening required '/var/www/blog/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:38 2014] [error] [client 127.0.0.1] PHP Warning:  require_once(/var/www/blog/wp-load.php): failed to open stream: No such file or directory in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:38 2014] [error] [client 127.0.0.1] PHP Fatal error:  require_once(): Failed opening required '/var/www/blog/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:39 2014] [error] [client 127.0.0.1] PHP Warning:  require_once(/var/www/blog/wp-load.php): failed to open stream: No such file or directory in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:39 2014] [error] [client 127.0.0.1] PHP Fatal error:  require_once(): Failed opening required '/var/www/blog/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:40 2014] [error] [client 127.0.0.1] PHP Warning:  require_once(/var/www/blog/wp-load.php): failed to open stream: No such file or directory in /var/www/blog/wp-blog-header.php on line 12 [Fri Jan 10 22:38:40 2014] [error] [client 127.0.0.1] PHP Fatal error:  require_once(): Failed opening required '/var/www/blog/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/blog/wp-blog-header.php on line 12   Reading online it seems to me that I also have to change the values of the home and siteurl fields into the wp_options database table (they contained references to the site on the old server), so I have change it with these values:   home: http://localhost/blog siteurl: http://localhost/blog   But the problem persist (I always see a white screen).  I think that maybe the problem could be that these value are wrong, or maybe I have change some other values? Or maybe I also create a specific .htacces file into my blog directory? (now I have no .htaccess file)  Do you have some idea about how to solve this problem?  Tnx  Andrea


Can mods see answer drafts from other users?

Yesterday I posted , about 5 minutes after I clicked on the "Post Your Answer" button I got some comments from a mod.  In one of them he said I had edited my answer in the first 5 minutes after posted and so that edit won't show up on the edit history. The thing is that I didn't make any edits to the answer (before or after the first 5 minutes).  He was pretty convinced that I had done those edits, so now the only theory that I have is that he was able to see the draft of the answer while I was writing it, that would explain why he saw different versions of the answer (the parts he said I added were at the end of the answer, so that would make sense).  So the question is, can moderators see answer drafts from other users?  Note: some of the comments are now deleted, so only mods/staff would be able to see the full thread, but this question still can be answered without seeing the complete thread.


So have found some issues with page content placing. It never happen to me before. So I have 3 pages of text and one table (which is 1 page length). These all pages are two sections. First section is 2 text pages and table, and other section is 1 page of text. Every page is one page length (I mean it is fully written page of symbols). And I don't know how all 3 text pages goes first, leaving table in 4 page. So my sections are messed up. Maybe any one could lend me some ideas, how to move my table from page 4 to it's right position in  page 3?  Thanks in advance


Doing math with \pageref (finding the last page number and adding 3)

So I'm writing an exam. It will have some as-yet-unknown number of pages P, and an additional 3 pages of a formula sheet. So the total length is N = P +3.  I need to write "This exam has $P$ pages, plus $3$ pages of formulas, for a total of $N$ pages".  I currently have a label at the end of the exam: \label{lastpage}, and so where I have P, I can write\pageref{lastpage}`.  But is there some way I can get N to be calculated automatically for me? I suspect it might exist in pgfmath, but I haven't used it in a while.


Why doesn't the rate of photosynthesis increase with increasing light energy (frequency)? I know that green light is not absorbed by chlorophyll, yet I am confused as to why this certain "frequency" is not absorbed. Intuitively, it makes sense that increasing frequency would make the rate faster.


Efficiently group adjacent list items in Python

I want to group adjacent list items with fixed numbers. Such as  a = [1, 2, 3, 4, 5, 6]  The result of groupby(a, 2) is [(1, 2), (3, 4), (5, 6)],  The result of groupby(a, 3) is [(1, 2, 3), (4, 5, 6)]  Here are my solution   def groupby(a, l):     ret = []     for idx in range(len(a)/l):         ret.append(tuple(a[idx*l:(idx+1)*l:]))     return ret   Is there more efficiently way to implement it?


Proof that $\sum_{k=0}^n \binom{k}{p}$ = $\binom{n+1}{p+1}$

I am currently doing a little self study on difference sequences and they use the following identity $$\sum_{k=0}^n \binom{k}{p}= \binom{n+1}{p+1}$$ I have never seen this identity without proof as if it is obvious, am I missing something is this an obvious result that perhaps is a consequence of some other theorem, if not could someone provide some intuition as to why this identity is true or even a proof. Any help is appreciated, thanks in advance.


I'm currently playing a DnD 3.5 campaign and the only sources we are currently using are: the PHB, the Dungeon Master Handbook, the Monster manual.  Now there seem to be a lot of other books out there, some belonging to DnD 3.5, some not. I'm a bit confused as towards how it all works. I understand of course that we can just choose what books to use. But which books are considered part of DnD 3.5? And is there a difference to DnD 3.5e? (i.e. what does the e stand for?)


I'm working on a WordPress site for my band and I'd like to mark every 3rd post on our blog page to have a special class applied to it, anybody have any pointers on how to achieve this? Any help is very very appreciated, thanks! rock n roll.


recursive function explained python (what is this part doing?)

def merge_sort(a):     if len(a)<=1:         return a     left = merge_sort(a[:len(a)//2])     //print('this is left step {}'.format(left))     right = merge_sort(a[len(a)//2:])     //print('this is right step {}'.format(right))     return merge(left, right)   i understand algebraic recursive functions i understand how it works.   what i dont understand is how merge_sort(a[len(a)//2:]) is getting just one number from the passed in list called 'a' (i have a def create_random_array that passes in  random list of numbers ).  my thinking was that it would first split the list in half-witch I could see in my print function, then it would split it again , and again until there is only one that can then be compared.   how does merge_sort(a[len(a)//2:]) work   other part of the code that might be useful to understand my mess   def create_array(size = 5, max = 10):     from random import randint     return [randint(0,max) for _ in range(size)]    def merge(a,b):     c = []     a_idx = 0     b_idx = 0     print(a[a_idx])     print(b[b_idx])     while a_idx<len(a) and b_idx<len(b):         if a[a_idx]<b[b_idx]:             c.append(a[a_idx])             a_idx+=1         else:             c.append(b[b_idx])             b_idx+=1     if a_idx==len(a):         c.extend(b[b_idx:])     else:         c.extend(a[a_idx:])     return c


I have the following Python code I am trying to execute but the interpreter is returning prematurely. I believe it is because I am trying to combine two dictionaries as if they were lists:  both = {} one = {"A" : 0} two = {"B" : 0} both = one + two    // Returns prematurely here   How can I combine two dictionaries into one?


Is $0.\overline{0}1$ possible in mathematical terms? I know that if you have a repeating decimal, the number is infinite and doesn't end. Thus, the 1 at the end here would stop the repeating decimal, am I right? Is this possible?


Hello I am currently trying to create a computer game\program and the main thing that it uses is input from the user, commands, in a JTextField. So I already have a basic text field set up called "question"  (JTextField question = new JTextField(15);) in a JFrame and an OK button to enter the text. Next is a String "answer". This is:       String answer = question.getText().toUpperCase();  This is how the field is set up. Net is the 3 if statements that give an error if no text is entered, if it is not the right word, and of course, the correct answer. They are as follows:  Public class ButtonListener extends ActionListener {      publix void actionPerformed(ActionEvent e)      {           if(e.getSource() == buttonOK)           {            String answer = question.getText().toUpperCase();            if(answer.length() == 0)           {                JOptionPane.showMessageDialog(                     Window.this,                     "ERROR: NO INPUT",                     "ERROR",                     JOptionPane.INFORMATION_MESSAGE);           }            if(answer == "XENIX")           {                JOptionPane.showMessageDialog(                     Window.this,                     "Welcome, Sir",                     "Greetings",                     JOptionPane.INFORMATION_MESSAGE);           }            if(answer != "XENIX" && answer.length > 0)           {                JOptionPane.showMessageDialog(                     Window.this,                     "ERROR: INCORECT PASSWORD",                     "ERROR",                     JOptionPane.INFORMATION_MESSAGE);           }   This is how the if statements react when text is entered and the ok button is pressed. Everything works but when I type in "Xenix", it says "ERROR: INCORRECT PASSWORD". The, "Welcome, Sir" message never shows, even though using a print method it shows it is clearly getting "XENIX" from the answer. Why is it not working? Is there another method I'm supposed to use? Please respond soon! Thanks!


I am making a presentation which is devided in two parts. The first part is about experiments held in instute A and the second part is about experiments held in instute A and institute B.  Is it possible to add a second logo in a beamer presentation after a certain frame?  Let's say that this is a previous slide    This is a next slide


What is the best resolution and quality for website

I'm thinking the pictures on my website are too large and heavy. I was looking for the best resolution and quality to export my pictures. I found some information that says 72dpi is enough resolution for a website but I didn't find any information about the quality and size.   I would like to know what is the best resolution, size and quality to have a nice picture that is not too big.


Cross product is defined in three dimensions the resulting vector have the same magnitude as the area of the parallelogram formed by the 2 multiplied vectors and its direction direction is perpendicular to the first two vectors. so Can we come up with an equation using the same analogy but in 4-dimensional space(so that the resulting vector's magnitude is the volume of the parallelepiped formed by the three input vectors and it's direction is -somehow- perpendicular to the first three vectors)?


Can it hurt to put my GRE score on my resume?

If my score is good and if I'm applying for an MS program in Europe, can it give me any kind of edge? The university I'm applying to requires GRE scores for certain programs but not the one I'm applying for. And if it won't be advantageous, can it hurt my prospects in anyway?


I'm on Ubuntu 19.04:  Tried:  But it still appears under Activities:  Any idea how to get rid of it?


$a,b,c$ are positive reals and distinct with $a^2+b^2 -ab=c^2$. Prove $(a-c)(b-c)<0$

$a,b,c$ are positive reals and distinct with $a^2+b^2 -ab=c^2$. Show that $(a-c)(b-c)<0$.  This is a question presented in the "Olimpiadas do Ceará 1987" a math contest held in Brazil. Sorry if this a duplicate. Given the assumptions, it is easy to show that $$0<(a-b)^2<a^2+b^2-ab=c^2.$$ But could not find a promising route to pursue. Any hint or answer is welcomed.


Potentially malicious software: was it removed?

I downloaded what may have been a malicious extension on Google Chrome. I don't know if that was a legitimate extension or not; I got it in order to access Pearson, hand-typing a link that another student (with no motive to prank me) showed me (am I a victim of ?). I was able to remove it from Chrome, which is a step above what I've seen another similar malicious extension do on another computer. How do I know if it is really gone?  If I am the victim of something malicious, is there any way that this could have compromised my Google account? I have that intertwined with a lot of things, including my university account. If so, what should I do? Is there any information that I have to go off of to justify buying a new computer?  The name of the extension was "Safe Search." The publisher is "Safely." It wasn't "Search Safely Search."


Inverse matrix as a sum of matrix powers

I have matrix $ A\in \mathbb{C}^{n x n}$ and $A$ is invertible.  How can I show that coefficients $c_0,...,c_{n-1}$ exist :  $A^{-1} = c_0I+c_1A+...+c_{n-1}A^{n-1}$  I tried to solve it first by multiplying the equation above with $A$ which gives:  $I = c_0A + c_1A^2 + ... +c_{n-1}A^n$  And I continued then by knowing that every square matrix can be written with Jordan canonical form ($A = VJ_aV^-1$):  $I = c_0VJ_aV^{-1} + c_1VJ_a^2V^{-1}+...+c_{n-1}VJ_a^nV^{-1}$  Which can be written in form:  $I = V(c_0J_a+c_1J_a^2+....+c_{n-1}J_a^n)V^{-1}$  After this point my task is to show that the identity matrix can be presented with sum of coefficients and Jordan canonical forms, but I don't have any idea how to do that or even if my approach to this problem is right.


Black GRUB screen when booting into dual-boot of Windows 8.1 and Ubuntu

Help! I had a dual-boot of Ubuntu and Windows 8.1 on my computer. Last night I decided to "uninstall" Ubuntu. Rather than re-install the Windows MBR I decided to just edit GRUB to timeout at 0, with the default choice as Windows. I restarted my computer and it boot just fine into Windows. I removed all the Ubuntu partitions from Disk Management (being careful not to remove the partition with mount point /boot/efi) and reclaimed the unallocated space.  Today I turned on my computer and a black GRUB screen came up with the line "Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions"  How do I boot in to Windows 8?!


Estimate battery's real capacity in real time

The maximum capacity of a battery during usage can vary from manufacturer's specifications due to factors like temperatures and battery health. Because of that i want to estimate the real maximum capacity (in kWh) of a battery using the percentage of the battery's remaining capacity (in %) and the current power consumption (in kW).  I will get the above mentioned measurements in real time, in a time interval of every second, i.e., in a time series. During data recording, i will never see a full battery charge cycle but instead the battery will be between ~95% and ~35% percent.  In my data exploration, i cumulated the current power consumption, visualized it together with the battery percentage and noticed that they share a linear dependency, as you can see in figure 1.  Figure 1: progression of battery capacity percentage and cumulated power consumption   My approach of holding measurements in a bin for every 2% lost battery capacity and performing on that bin a linear regression to predict the cumulated power consumption at zero percent battery capacity is giving me rather unstable results. (see figure 2)  Figure 2: estimated capacity of every two percent battery capacity    Is there a way to get the results in a more stable (less varying) state? Or is there even a more exact way to estimate the current maximum capacity of the battery using a different method?


If light has mass, then why don't we have light particles accumulated all over the earth?


I am trying to come up with a model by using negative binomial regression (negative binomial GLM). I have a relatively small sample size (greater than 300), and the data are not scaled. I noticed that there are two ways to measure goodness of fit - one is deviance and the other is the Pearson statistic. How can I determine which goodness-of-fit measure to use? Are there some criteria that I can take a look at in selecting the goodness-of-fit measure?


I want to get log details between two dates but I am unable to print anything with the command:  egrep "^\[MAY 16 11:00:00\]"  alert.log -A 10000 | egrep "^\[MAY 16 16:30:00\]" -B 10000


I have a string with a return value, i want to compare return value with an edittext's text. but i cant do this. my code is like this :      public static String  login (String a)       {             String Pass = null;             InputStream is = null;             String result = "";             ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();             nameValuePairs.add(new BasicNameValuePair("UName", a));              try{                     HttpClient httpclient = new DefaultHttpClient();                     HttpPost httppost = new HttpPost(LoginAddress);                     httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));                     HttpResponse response = httpclient.execute(httppost);                     HttpEntity entity = response.getEntity();                     is = entity.getContent();              }catch(Exception e){                  Log.e("log_tag", "Error in http connection "+e.toString());                 Pass = "Error Connection";             }              //convert response to string             try{                     BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);                     StringBuilder sb = new StringBuilder();                     String line = null;                     while ((line = reader.readLine()) != null) {                             sb.append(line + "\n");                     }                     is.close();                     result=sb.toString();             }catch(Exception e){                     Log.e("log_tag", "Error converting result "+e.toString());                     Pass = "Convert Error";             }             //parse json data             try{                     JSONArray jArray = new JSONArray(result);                     for(int i=0;i<jArray.length();i++){                          JSONObject json_data = jArray.getJSONObject(i);                             Log.i("log_tag", "UPWord: "+json_data.getString("UPWord"));                             Pass = json_data.getString("UPWord");                      }             }catch(JSONException e){                     Log.e("log_tag", "Error parsing data "+e.toString());                     Pass = "Wrong Username or Password";             }              return Pass;         }      and i call it like this :          public void onClick(View v)         {             StrictMode.setThreadPolicy(policy);               EditText Username = (EditText) findViewById(R.id.Usernme1);             EditText Password = (EditText) findViewById(R.id.Passwordd1);               String Result = DownLeftFragment.login(Username.getText().toString());              if (Result == Password.getText().toString())             {                 Intent intent = new Intent(MainActivity.this,HomePage.class);                 startActivity(intent);             }             else if (Result == "Wrong Username or Password")             {                 Toast.makeText(MainActivity.this, "Wrong Username or Password", Toast.LENGTH_SHORT).show();                  }             else if (Result == "Error Connection")             {                 Toast.makeText(MainActivity.this, "Error in network connection", Toast.LENGTH_SHORT).show();                     }             else if (Result == "Convert Error")             {                 Toast.makeText(MainActivity.this, "Error in app", Toast.LENGTH_SHORT).show();                    }             else              {                 Toast.makeText(MainActivity.this, Result, Toast.LENGTH_SHORT).show();                      }          }   i defined 2 edittexts, Username1 and passwordd1, it works fine with Username1.getText().toString(), but not with passwordd1.  (if) works fine with all of (else if)s . but not with main if (if (Result == Password.getText().toString()))


Show that the probability that it falls entirely on one brick is $\frac{(a-c)(b-c)}{ab},( c<a, c<b).$

Question: A floor is paved with rectangular bricks each of length $a$ units and breadth $b$ units. A circular disc of diameter c is thrown on the floor. Show that the probability that it falls entirely on one brick is $\frac{(a-c)(b-c)}{ab},( c<a, c<b)$   I tried to solve but ended up getting $\frac{\pi^2}{4ab}.$ What am I missing?Help!


When exactly did Renly discover Joffrey is illegitimate?

In books? In series? I thought in either, it was because of Stannis' letters that he first came to know it (or if he didn't believe it: he was first came to be informed about about such possibility), but that doesn't seem to add up with Renly convincing Ned to kidnap Joffrey.    Related questions:  , ,


What are the best practices to do transactions in C# .Net 2.0. What are the classes that should be used? What are the pitfalls to look out for etc. All that commit and rollback stuff. I'm just starting a project where I might need to do some transactions while inserting data into the DB. Any responses or links for even basic stuff about transactions are welcome.


How can I modify a bounty notice (e.g., fix a typo)?

I made a typo while offering a bounty on the question  Is there a way to fix spelling on bounty notice? Can site moderators do this?


When working with large documents, or even across multiple (smaller) documents, I often find that I forget which typographical consistencies I should stick to.  With TeX being inherently consistent in the way it does things, most things are kept organized without the user even knowing about it. Additionally, using a customized documentclass (like , for example) or packages (like  and , to name two) improves on this consistency by user's choice. Sometimes, however, you are left to your own devices and have to do things manually. Of course, the latter could also stem from not knowing that a package exists to do the job for you, or because you'd rather have more control over the placement/use of a certain things without having it automated or globally set.  To this extent, I though this would be a good place to ask the question: "Which tools/techniques do you use to maintain consistency within your document?"  Sure, the question sounds broad. Many answers are scattered across this site and elsewhere (like the  or Bringhurst's ). I was hoping to contain this diverse knowledge base in one location on TeX.SX (similar to what was done for  and ).  Here are some examples of useful (manual) tips/tricks:   The TeX Book mentions (p 25) the use of ties (~) in the context of Thor's "A SHORT STORY" when typesetting Mr.~Drofnats:     A good typist will use ties within names...   provides a good example of when/why to use either \emph or \textit. The contents of  has some very relevant manual application of consistencies, including:   Put a tilde before references or citations, e.g., Jie~\cite{habit06}. Differentiate between text comma and math comma, e.g., type for $x=a$, $b$, or~$c$ instead of for $x=a,b$, or $c$. Write ellipsis using \ldots instead of three dots.  The  also provides an interesting list of "do's and dont's".   Any more?


Unable to store Japanese characters in Maria DB

We are trying to store some text with Japanese characters inside Maria DB 5. However, we can see only question marks after save.  We tried to set UTF-8 encoding with following command, but this also does not help.  ALTER DATABASE my_db COLLATE = 'utf8_unicode_ci'; SELECT * FROM INFORMATION_SCHEMA.SCHEMATA where schema_name = 'my_db';   Any clues?


Did the broomstick industry stop research after the Firebolt?

For the first three years of Harry's Hogwarts life, we see a new broom coming out as the fastest each year:     Several boys of about Harry’s age had their noses pressed against a window with broomsticks in it. “Look,” Harry heard one of them say, “the new Nimbus Two Thousand — fastest ever —”   -Harry Potter and the Philosopher's Stone, Chapter 5        “Very latest model. Only came out last month,” said Flint carelessly, flicking a speck of dust from the end of his own. “I believe [the Nimbus Two Thousand and One] outstrips the old Two Thousand series by a considerable amount.   -Harry Potter and the Chamber of Secrets, Chapter 7        “Just come out — prototype —” a square-jawed wizard was telling his companion.   “[The Firebolt is] the fastest broom in the world, isn’t it, Dad?” squeaked a boy younger than Harry, who was swinging off his father’s arm.   “Irish International Side’s just put in an order for seven of these beauties!” the proprietor of the shop told the crowd. “And they’re favorites for the World Cup!”   -Harry Potter and the Prisoner of Azkaban, Chapter 4   There's no mention of a faster broom in any of the remaining books. So, did the broomstick industry just stop their research after the Firebolt came out? Or were they unable to make anything better than the Firebolt?


Logic for decomposing a permutation into different products composed of transpositions

I know that any permutation cycle can be decomposed into transpositions as follows:     $(a_1,a_2...,a_n) = (a_1,a_{n-1})...(a_1,a_2)$   But in my book there is an example of the following form     $(1,2,3,4,5) = (5,4)(5,2)(2,1)(2,5)(2,3)(1,3)$   I verified that it holds true. But I cant seem to figure out how the author came up with that. Also, What is the generic algorithm to produce all decompositions of permutation in terms of transpositions.


Should one pronounce THE [in this case, THEE] when the following word begins with a vowel and THA when the following words begin with a consonant

THEE Apple, THEE Engine, THEE Imbecile, THEE Orange, THEE uncle and THA...for all [most] words beginning with consonants


What is the purpose of condenser lenses in the slide projector shown below?

I searched a lot on internet about this.I could not find the working of these condenser lenses in detail. Some websites say that condenser lenses make the light rays parallel and  to pass through every part of the slide. I can not figure out how? Moreover those websites say nothing about  replacing these condenser lenses with a single convex lens.I also wonder what will happen if we place the condenser lenses with their plane faces facing each other? I need help


Displaying the wireframe of a beveled Bezier curve

I'm following a tutorial in which a Bezier curve is supposed to represent a vine. The vine is a collection of control points with their bevel depth and bevel resolution set appropriately:    However, the vine in the tutorial's included .blend file displays its wireframe over the typical solid viewport shading:    In both .blend files, Object Mode is selected. How do I get my .blend file to display a wireframed Bezier curve?


I have Ubuntu server 12.04 installed, so I have no GUI. When I do the command ifconfig, I cannot find my internal IP address. It says inet addr: 127.0.0.1. Here is the output of ifconfig -a: eth0   link encap:Ethernet  HWaddr 00:06:4f:4a:66:f0     BROADCAST MULTICAST  MTU:1500  Metric:1     RX packets:0 errors:0 dropped:0 overruns:0 frame:0     TX packets:0 errors:0 dropped:0 overruns:0 carrier:0     collisions:0 txqueuelen:1000     RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)  eth1   link encap:Ethernet  HWaddr 00:16:ec:05:c8:9c      BROADCAST MULTICAST  MTU:1500  Metric:1     RX packets:0 errors:0 dropped:0 overruns:0 frame:0     TX packets:0 errors:0 dropped:0 overruns:0 carrier:0     collisions:0 txqueuelen:1000     RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)  lo     Link encap:Local Loopback     inet addr 127.0.0.1  Mask:255.0.0.0     inet6 addr:  ::1/128 Scope:Host     UP LOOPBACK RUNNING MTU:65536  Metric:1     RX packets:1800 errors:0 dropped:0 overruns:0 frame:0     Tx packets:1800 errors:0 dropped:0 overruns:0 carrier:0     collisions:0 txqueuelen:0     RX bytes:143896 (143.b KB)  TX bytes:143896 (143.8 KB)  here are the contents of etc/network/interfaces: # The loopback network interface auto lo iface lo inet loopback  # The primary network interface auto eth0 iface eth0 inet dhcp  If someone could edit this for me, the contents of etc/network/interfaces should be on separate lines. The output of host askubuntu.com was: ;; connection timed out; no servers could be reached.  I set up owncloud and webmin a few months ago and was using them for a month with no problems. I think the power went off one day 2 months ago and I never turned the server back on until yesterday. I haven't done anything that would have affected the internet setup So i'm not sure why it doesn't work anymore. As far as my network topology goes, I have a pci-e network card for the pc. The ethernet line goes from the network card to a switch, and then to a modem/router from there.


Difficulty with Motion/Pos etc. NBT manipulations

I'm fairly (but not completely) new to the revised command block functionalities and functions themselves but I think I've got a pretty competent understanding to get me by.  Basically, I'm trying to create a "hose" mechanic where, when the player holds shift with a specific item (I can do that bit easy enough), it summons falling blocks in front of the player with a set "forward" motion that is relative to the player's facing direction. I've tried doing a ray-casting technique but I want the "water" coming from the hose to have a natural looking falling animation which ray-casting doesn't do.


Which one is correct?   Their quitting on you is their loss. Them quitting on you is their loss.


Extracting each digit of an integer into an array?

My goal is to convert an integer:  int = 1234;   to an array:  int converted[] = {1,2,3,4};   Can you give me a tip what I will need for programming this?


Does 20.10 version of ubuntu works with secure boot enabled?

I have an HP PC in which I have installed Windows 10 and would like to also install ubuntu in dual boot but will it work with secure boot in UEFI or I will need to disable secure boot to run ubuntu?


What is the difference between a sudo and a root user?

I'm using the windows subsystem for linux, I'm very new to ubuntu and I can't get my head around the root user concept.


What is the benefits of using snap instead of apt?

I am currently investigating Canonical's snap and deciding whether or not I will use it as default package manager.  The benefit I clearly see is that it sometimes offers more recent versions of some apps.  Are there any other benefits of using snap instead of apt? This is practical question and not to waste your time.   Currently, most material I found is about hype without rationale. Thanks.  Yes, here is similar question:    In my opinion that question is very wordy and does not convey the main question:   What benefits(deciding factor) snap will give one to consider switching?.   So one might think that my question is more relevant.


What could be legitimate reasons for heavily downvoting a post on meta

On this site, I've not seen a whole lot of very upvoted questions, unlike on other sites.  But in the past couple of days alone at least two questions have been downvoted up to 26 times. I personally took very long to get to even the rep I have now on this site.  Why do you think that is? Is this site really that controversial?


In the finale when they mention the Cloister bells ringing they also refer to the things down there,      The Cloister Wraiths. I thought the Cloister Bell was just a bell on the TARDIS, and did not refer to a race? Are they a Gallifreyan race, or a different race like the Sisterhood of Karn?   What race are these creatures?


Why does the frequency of a wave does not change on reflection and on transmission?

I wanted to know why the frequency of a wave does not change even on reflection or  transmission and does it only depends on the source only.


Blender 2.90.1: HDRi rotated and repeated

All the hdri (downloaded from hdri haven) appear to me rotated and "duplicated?", I have reset blender to factory values (version 2.90.1) and it remains the same, could someone tell me why this is happening?


Install Ubuntu on D:\ drive partition as Dual-boot with windows 7 on a SSD C:\ drive

Im not familiar with Ubuntu or Linux in general but have succesfully installed dual-boot windows7/Ubuntu on a single harddisk on my private PC. I used the "Install Ubuntu alongside them"-option.   On my work PC I have an existing windows 7 64-bit installation that boots from BIOS firmware on a SSD drive (C:), and have my working data (documents etc) on a partition on a separate disk (D:). I now want to install Ubuntu (v 14.04.3) on the remaining unformatted space on D:\ using with the option of choosing system using GRUB. There are of cause fine descriptions around (e.g.  and ). My question is how to setup the partitions in the "something else"- option during the Ubuntu installation.   In  tutorial they assume that all partitions on the D-drive can be deleted; however I only obviously want to keep the working data on the existing D-partition, and place Ubuntu on the residual space (or part of it) on the D:-drive.  A) How is this ensured ? B) how many partitions should I make (boot, root, home, swap ?)  C) and should boot be made primary, and the others logical ? D) Should I set Device for boot loader installation as/dev/sdb - will this not erase the existing D-partion ?


Ambiguity with appearance as plural or singular

It is more common to write: "People care too much about their appearance." This is because it is being used as a "non count" noun and the plural could confuse people into thinking the writer means the occasion when someone is in a play, movie, etc.  So with our would you still use singular?  Note that these dictionaries note it as being singular or plural (appearance as looks):    Anyone shed light?


"suggest you follow" or "suggest you to follow"?

For example, is it:     We strongly suggest you follow the official guide.   Or:      We strongly suggest you to follow the official guide.   ?


This is an assignment and a question for measuring basic knowledge on C.  It is part of a course on Coursera.org. But, this is just to measure if you are able to do the course. This is just a copy-paste of the actual question. I did great on all other question, I just don't seem to get the following one :  Suppose you are compiling for a 32-bit platform and sizeof(int) == 4. Which one of the following is equivalent to c[b] if c is of type int* and b is of type int?  Possible answers:  -1 * b[c] *(c+b) none of the above *c+b c[b][0]   What I am asking is, what the right answer is from the above possibilities, and why?  I mean what logic does one use to arrive at the result? What should I read to understand the procedure to get there ?


dpkg: error: parsing file '/var/lib/dpkg/updates/0040' near line 0: newline in field name '#padding'

I am getting this dkpg error when I try:  sudo dpkg --configure -a   Unable to find a workaround.   Using Ubuntu 16.04


Can I play Blu-ray discs directly on a MacBook using an external drive?

Is is possible to use an external drive to play Blu-ray discs on a MacBook? It has a Core2Duo processor and 9400m graphics. does it need any software, either paid or free?


Solution to exponential function in natural numbers

I was wondering if there exists a pair of natural numbers $n, m \in \mathbb{N}$, such that $e^n = m$? Of course excluding the simple solution (0,1). Intuitively, I would say no. However, I am far from finding an argument, nor knowing which theory even treats these types of questions. Cheers


How much of a difference is there between photos where perspective is fixed in post as opposed to being shot with a tilt lens?

I've been doing some architectural photography and indoors with the Nikon 14-24 f2.8 lens.  Most of the time I can get my camera high enough to frame my shot and keep vertical lines vertical. But there are times when I want a low- or high-angle shot, so I end up using the new "Upright" tool in Lightroom to straighten my photos out in post.  I've never used or owned a tilt-shift lens before, so my question is how much of a difference is there between photos that have the perspective fixed in post as opposed to being shot with a tilt lens?


Exactly under what conditions would the equality $f(x)=f^{-1}(x)$ hold? The proof attached below considers a special case when $f$ is strictly increasing. The theorem then says that the set of solutions to $f(x)=x$ will always be a superset of the set of solutions to $f(x)=f^{-1}(x)$. Any suggestions on how to improve this proof will be much appreciated.  However, most high school texts seem to assume in all cases to solve $f(x)=f^{-1}(x)$, simply solve $f(x)= x$. We know that this method, if it works at all, is at best a sufficient but not necessary condition. So, is there a precise set of conditions such that our desired equality will hold?    Edit: to avoid any miscommunications, my question is not related to the concept of involution functions. Involution functions are functions that are their own inverses. On the other hand, my question doesn't require $f^{-1}$ to be equal to $f$. I am merely interested in finding under what conditions will the equality $f=f^{-1}$ holds. And yes, just to clarify, I am looking at invertible functions. Thank you to whoever who pointed that out.


I'm trying to install Ubuntu 16.04.3 (latest downloadable LTS) on my Acer V17 Nitro. It has a 256 Gb SSD, where I want the Ubuntu and the swap to live and a 1Tb HDD, where I will have long-term storage and probably a Windows partition for my wife to use from time to time (she doesn't like Ubuntu no matter what I do).   So I cleared out the SSD and am trying to install Ubuntu from the bootable drive I created from another Ubuntu 16.04 machine.   But no matter what combination of parameters I try (installing updates or not, installing 3rd-party software or not), when it comes to rebooting after the install it gives me this (and does not reboot):     I have tried what was proposed in  and that way it does reboot, but sais can't find a bootable medium.  I have also tried booting from the USB drive with nomodeset instead of quiet splash as suggested  but then it does not load and the screen just goes black.  UPDATE  Decided to take a different route and install Windows first and then put Ubuntu next to it.   I divided the SSD partition into 3 parts - swap, 140Gb for Ubuntu and 80Gb for Windows (using Windows 10 Home).   I installed Windows on its partition and it happily took its place and is running smoothly.  I then tried to install Ubuntu with nouveau.setmode=0 as discribed in . It did install and went on reboot fine, but I am not able to boot Ubuntu, it boots directly to Windows.   And yes, I have tried Boot-Repair and moved the Windows Boot Manager to the bottom of the BIOS Boot sequence. Still it's not working.


Is it necessary to call `ssh-add` after login

I have my public key on the server, I have my personal key in ~/.ssh/identity. If I execute ssh-add and enter my private passphrase, I can ssh without a password.  What I want is not to call ssh-add at all. I want to unlock the private key with the login to the system. I tried (maybe foolishly) import the identity file into the seahorse, but without any effect.  I don't want to have private key without a passphrase. I have Ubuntu Gnome 14.04.


I have some doubts regarding capitalizing or not the following words:   Communism Communist   I know that Communism is generally written with capital letter, but sometimes I have this doubt and cannot come up with a plausible solution. For example, in: "During Communism/communism people had to...".  As far as communist is concerned, I am pretty sure that it is usually not capitalized, at least, if it is not part of a name, like "the guidelines of the Communist Party of Something". Is that correct or am I missing something?  Thank you in advance for any suggestion you might have!


Prove that $\ln{n} \lt \sqrt{n}$ for $n \in \mathbb{N}^{*}$ without derivative

Prove that $\ln{n} \lt \sqrt{n}$ for $n \in \mathbb{N}^{*}$.  I have tried to prove that using induction but I really don't know how to do it.  I know how to solve it by creating a function $f(x) = \sqrt{x}-\ln{x}$ and then making the derivative, and then show that is bigger than 0. But I need it solved without math analysis (without derrivative, maybe with induction).  How can I do this? Thank you very much!


Email for domain vs subdomain at two different locations

I would like to know if I have a domain foo.bar and want to host the main email server at other provider, such as by google, simultaneously having another email server subdomain.foo.bar locally.   In other words, emails to user@foo.bar will be handled by external host while emails to user@subdomain.foo.bar will be handled by a local email server. Both cater to global clients.  Is it a usual practice to do so?


I have a software which when I go its directory path in terminal I run ./myprogram and my application start so I want to know how to understand which files are reading by my program  which is not related to my program? for example suppose my program read files from system how to know which are this files?


Python's "//" operator treated as a comment

s = 5 // 2 if s == 2:   print(s)   As you can see the highlighting system treats Python's floor division operator // as the beginning of a comment. But // is not a comment in Python. Is there any solution? Is it a bug?


Prove that two paths connected from opposite sides of a square must interesect.

Lef $f,g: I \rightarrow I^2$ be continuous and $f(0) = (a,0), f(1) =  (b,1)$ and $g(0) = (0,c), g(1) = (1,d)$.  Prove that there exist $t_1, t_2 \in I$ such that $f(t_1)=g(t_2)$   The book is hinting to use (if $h : D^n \rightarrow D^n$ continuously then there exists a fixed point) to find a function from $I^2 \rightarrow I^2$, but I can't find anything that works even if I replace $D^n$ with $I^n$ by homeomorphism.


How to generate unique id in javascript?

I want to log traffic on website. On every hit I want to generate unique Id that will will be stored in database. To generate unique Id I wrote below code, but some time I get same entry in database.   timingVar = 'load_'+Date.now()+'_'+uniqueid();  //function used to generate unique number// function uniqueid() {     var ALPHABET = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';     var ID_LENGTH = 8;     var rtn = '';     for (var i = 0; i < ID_LENGTH; i++) {       rtn += ALPHABET.charAt(Math.floor(Math.random() * ALPHABET.length));     }     return rtn; }


How do the customized world settings work?

In  (snapshot ) and later, there is a new  world type. It is based on , but the settings are different. How do they work?


I'd appreciate if anyone could help me figure out what font Munkres used in his famous "Topology" book. I am interested in the font used in the main body as well as the font used in his "theorem" environment.  I searched the Internet for similar questions with no success. I also tried "myfonts.com," but that did not yield any satisfactory results. Finally, I looked at PDF version of his book and by going to "documents properties," I checked the fonts that the pdf viewer was able to detect. However, the results (mainly variations of Courier, Helvetica, and Times) do not look quite similar to what it really is.  The reason I am asking this question is that Munkres strikes me as an incredibly easy book to read and I would like to format my papers in a similar manner. As a example, his "f" in a theorem environment looks differently than his "f" in a math mode, which makes it extremely easy to distinguish between the two.  Below you can a few screenshots from his book.  Thank you for all your help.  EDIT: I understand that some of you may think it is a duplicate of  , but I tried methods mentioned in that post and it did not solve my problem. However, thankfully some of you have already answered my question, which I am very grateful for.


I need to prove this limit:     Given $f:(-1,1) \to \mathbb{R}\,$ and $\,f(x)>0,\,$ if $\,\lim_{x\to 0} \left(f(x) + \dfrac{1}{f(x)}\right) = 2,\,$ then $\,\lim_{x\to 0} f(x) = 1$.


I stumble on this summation during an exercise. How can I resolve $\sum_{x=0}^{\infty} xe^{-x/\theta}$?


I'm still struggling with the idea of a massless particle (photon) having momentum.  if p = mv then if m=0, p=0  Even in the approach of :  p = mv / Sqrt(1-v^2/c^2)  = p=ymv  if velocity is equal to the speed of light, p would still equal 0?  am I missing something here?  thanks


I would like to know how to upgrade from my current version of Ubuntu to the next stable from the Command line interface?


I've been thinking about the following situation in the theory of relativity which leads to a paradox: Two spaceships orbit a planet, on the same circular orbit, moving in opposite directions. For an external observer the two spaceships behave the same way and their clocks stay synchronized. The spaceships are in free fall so to each of them one can attach an inertial frame and Lorentz transformations should apply. An observer in say spaceship #1 will see spaceship #2 travelling on a circular orbit, passing by periodically. According to special relativity the clock in spaceship #2 will appear ticking slower.  However after completing a trip in orbit at the next meeting the clocks of the 2 spaceships should still be synchronized. How can this be explained?


does "javascript:" do something in an event attribute?

In the following html piece, does javascript: do something?  <input type="text" name="Name" id="Name" value=""   onkeydown="if(event.keyCode == 13){                   if(IsValidBrowser()==true){                           javascript:Continue();                         //^^^^^^^^^^^                   } else {                      alert('Please use Safari, Google Chrome, or MS                       Internet Explorer version 7.0 or higher.');                   }            }"  />   I thought that javascript: was only to be used in the href property of a <a> tag, but I run into this.  Thanks.


Ubuntu 16.04: Can't update packages because of IPv6 address

I have a fresh installation of Ubuntu Server 16.04 LTS (Xenial Xerus).  I added this to /etc/network/interfaces to assign an IPv4 address:  auto enp2s0 iface enp2s0 inet static  address 192.168.1.100  netmask 255.255.255.0  gateway 192.168.1.1   However, the interface gets an IPv6, too. I don't know where it is coming from. There shouldn't be any IPv6 in this network, but I can't deny the possibility that some device is trying to assingn IP addresses, which is why I did not enable DHCP.  Now this seems to trigger AAAA instead of A lookups which prevents me from doing an apt-get update:  Cannot initiate the connection to th.archive.ubuntu.com:80 (2001:3c8:9009:81::101:34). - connect (101: Network is unreachable) [IP: 2001:3c8:9009:81::101:34 80]   What to do?


Preventing robots from crawling specific part of a page

As a webmaster in charge of a tiny site that has a forum, I regularly receive complains from users that both the internal search engine and that external searches (like when using Google) are totally polluted by my users' signatures (they're using long signatures and that's part of the forum's experience because signatures makes a lot of sense in my forum).  So basically I'm seeing two options as of now:   Rendering the signature as a picture and when a user click on the "signature picture" it gets taken to a page that contains the real signature (with the links in the signature etc.) and that page is set as being non-crawlable by search engine spiders).  This would consume some bandwidth and need some work (because I'd need an HTML renderer producing the picture etc.) but obviously it would solve the issue (there are tiny gotchas in that the signature wouldn't respect the font/color scheme of the users but my users are very creative with their signatures anyway, using custom fonts/colors/size etc. so it's not that much of an issue). Marking every part of the webpage that contains a signature as being non-crawlable.   However I'm not sure about the later: is this something that can be done?  Can you just mark specific parts of a webpage as being non-crawlable?


I find it funny that Java (or the java.util library) does not have a built-in function to calculate difference in dates. I want to subtract one date from another to get the elapsed time between them. What is the best way to do this?   I know the simple way is to take the difference of the time in milliseconds and then convert that into days. However, I wanted to know if this works in all cases (with daylight saving, etc.).


Is there a way to schedule airplane mode for iphone?

This question was essentially asked 3+yrs prior, but I don't see any recent updates.   I'd like to set my iphone to engage airplane mode for an hour (example) and then turn off airplane mode/engage cellular service an hour later.  Is that possible?


Is it possible in Ruby to get a reference to methods of an object ( I would like to know if this can be done without procs/lambdas ) , for example , consider the following code :   class X   def initialize     @map = {}     setup_map   end    private   def setup_map     # @map["a"] = get reference to a method     # @map["b"] = get reference to b method     # @map["c"] = get referebce to c method   end    public   def call(a)     @map["a"](a) if a > 10     @map["b"](a) if a > 20     @map["c"](a) if a > 30   end    def a(arg)      puts "a was called with #{arg}"   end    def b(arg)      puts "b was called with #{arg}"   end    def c(arg)     puts "c was called with #{arg}"   end end   Is it possible to do such thing ? I would like to avoid procs/lambdas because I want to be able to change the behaviour of A,B,C by subclassing .


Is there a term for when just by saying that something is broken and showing it to someone fixes the issue?

This seems to be a common enough occurrence that it would merit its own phrase. I imagine it might be some sort of subset of Murphy's Law. But it's specific enough that Murphy's Law doesn't quite address it.  Do you know when you are banging your head against a wall for hours trying to fix something? And then when you finally give up and try to get someone else to come fix it (or even just look at it to see that it's broken), it's working perfectly as if nothing had ever happened? And at this point, you're just trying to convince the other person that it was broken in the first place.  It'd at least take some of the frustration out of the experience if you could both just laugh about <insert the phrase for it here>. But as it is now, I basically have to go through the whole paragraph above to say it, and at that point the joke is kind of lost.


A quote within a quote uses single quotes. What about within that? And deeper?

Replacing the unknown quote marks with underscores, let’s say we’re trying to write this:  He responds, “Joe said ‘Mark said _I’m not coming._’”  One option is to alternate: He responds, “Joe said ‘Mark said “I’m not coming.”’”  Would it be crazy to use single or double angle quote marks? Like: He responds, “Joe said ‘Mark said ‹I’m not coming.›’”  I’m getting nowhere googling it.  Is there a better option?  I realize that, generally, the text will read better if it’s rephrased to nest less deeply. But I ask not as an author, but somebody formatting others’ work.  Edit: , and the question it’s marked a duplicate of, are not duplicates of this question because they discuss two-deep embedded quotes, whereas this question assumes the solution to two-deep quotes (use single quotes) and asks about quotes three or more levels deep.


Can anyone help with this sentence? Is my punctuation here correct?  If you sell bicycles, sell as many accessories as you can; water bottles; pumps; and biking gear, such as shoes, gloves, caps and more.


Recently, I stumbled over some configuration files. To gather more information about its structure and how the its used, I either do a quick research on the internet (just ask Google) or use the man command directly in the terminal.  In most cases it is obvious by which application the configuration belongs to which configuration file. The man page of the application refers to other man pages for further information and documentation. In the case I have no idea, a man -k file-or-path or apropos file-or-path points me sometimes in the right direction.  This approach works in most cases, but not always. Is there a convenient way to get more information in cases where I have no clue (apart from a research on the internet)? What are other strategies? Are there tools (some kind of ZSH plugins) you may recommend?


Is it possible to have a basis for a covariance matrix such that the greatest variance is greater than the variance of the first eigenvector?

Suppose we have a covariance matrix $C$. Define the eigendecomposition, $C = Q^{-1} \Lambda Q$ and some other arbitrary basis $C = B^{-1} D B$.  Define $V_\text{PCA} = \text{diag}(QCQ^{-1})$ and $V_B = diag(BCB^{-1})$, and assume they're both sorted by magnitude. Define $T_\text{PCA} = \text{sum}(V_\text{PCA})$ and $T_B = \text{sum}(V_B)$. Is it possible that $V_\text{PCA}[i] / T_\text{PCA} < V_B[i] / T_B$ for $i = 0$? If so, how is this possible? Doesn't it violate the idea that PCA initially finds the basis vector with maximum variance?  I can understand how the inequality holds for $i > 0$, due to the orthogonality constraint of PCA which may not result in the "optimal" vectors being found in the variance-explained sense.  I'm trying to figure out if there's an error in my code, so please forgive the convoluted notation, but I want to be as clear as possible about what I'm seeing.


Why does a function and its inverse always intersect on the line y=x

I've been working through a textbook and noticed that if a function intersects with its inverse function it's always on the line y = x. Why is this?


Regarding a question in elementary number theory

I am trying assignment of an Institute in which I am not a student and I am unable to think about this problem.      Problem If there exist integers $a$ and $b$ such that $(a, b) = 1$ and $1+ \frac{1}{2} + \ldots + \frac{1}{p-1} = \frac{a}{b}$ then prove that $p^2 | a$ , assuming that $p\geq 3$.    Can someone please help how to approach this problem.


spectral theory of Laplacian on $\mathbb R^n$

Can you describe the spectrum of the Laplacian $ \Delta : H^2(\mathbb R^n) \subset L^2(\mathbb R^n) \rightarrow L^2(\mathbb R^n)$?  I am interested for which values $z \in \mathbb C$ the equation  $\Delta u + z u = f$  has a solution $u \in H^2(\mathbb R^n)$ for every $f \in L^2(\mathbb R^n)$. I think that the point spectrum is empty, but is every $z$ in the resolvent set?


I apparently have multiple versions of a module installed and I am trying to figure out where the files are because only one of them is from package management and I want to delete the other.  Is there a simple way to ask Python where it found a module after importing it?


How to retrieve objects that are not created by the user?

This question might be weird, but i want to retrieve objects except  the objects created by the login in user   Well  i tried this code in my view  def getobjects(request):     products=Products.objects.filter(user!= request.user)   But does not work.  In model   class Products(models.Model):     name=models.Charfield()     user=models.ForeignKey(User)   I will need help with the right query function to handle this. Thanks in advance


Is there another word for agnostic when used in reference to technology?  For example      The keyboard is OS agnostic and operates on most modern operating systems.


Prove that $\lim_{x \to \infty} f(x) = 0$

Let $f : \mathbb{R} \to \mathbb{R}$ be a continuous and differentiable function. If $\lim_{x \to \infty} ((f'(x))^2 + f^3(x)) = 0$, prove that $\lim_{x \to \infty} f(x) = 0$.  Here is what I did so far:  $\lim_{x \to \infty} ((f'(x))^2 + f^3(x)) = (\lim_{x \to \infty} f'(x))^2 + (\lim_{x \to \infty} f(x))^2 \cdot \lim_{x \to \infty} f(x) = 0$  From this, we can conclude that $\lim_{x \to \infty} f(x) \leq 0$.  Now, I need to prove that $\lim_{x \to \infty} f(x)$ can't be negative, but I didn't figure out how to do this yet.  Thank you!


What is the nicest way to say "old person" while still being polite and non-offensive?

So I was working on a presentation and I was using the word elderly, but the evidence I was using had the word senior in it. And I was thinking that the word elderly was polite and non-offensive, but now I am not sure. Any ideas on what word is non-offensive and polite?


Ubuntu 20.4 apt --fix-install broken /boot/ 100% full

I have problem with installing new updates on my ubuntu. While researching I came up to my conclusion that /boot/ is full at 100%, not even auto-remove works (says run apt-fix install first) when i run apt-fix it errors.


Proving that the number of vertices of odd degree in any graph G is even

I'm having a bit of a trouble with the below question     Given $G$ is an undirected graph, the degree of a vertex $v$, denoted by $\mathrm{deg}(v)$, in graph $G$ is the number of neighbors of $v$.   Prove that the number of vertices of odd degree in any graph $G$ is even.


I have a line of best fit. I need data points that will not change my line of best fit

I'm giving a presentation about fitting lines.  I have a simple linear function, $y=1x+b$.  I'm trying to get scattered data points that I can put in a scatter plot that will keep my line of best fit the same equation.   I'd love to learn this technique in either R or Excel--whichever is easier.


How do we prove that $\lfloor0.999\cdots\rfloor = \lfloor 1 \rfloor$?

Are the floor functions of $0.999\cdots$ and 1 equal?  It is true that $0.999\cdots=1$ but how does one justifies the integer part of $0.999\cdots$ being 1 , where it is not, or alternatively without using $0.999\cdots=1$ how can we show that  $\lfloor0.999\cdots\rfloor = \lfloor 1 \rfloor$ ?


The "x characters remaining" indicator on comments shows red for 350 characters remaining, but changes to blue when there are 250 characters remaining

While typing out a rather long comment, I noticed the "x characters remaining" turns read when you get below ~350 characters remaining:      That's great, but it turns to blue another ~100 characters later:      What's up with that?  I realize  blue can mean "caution", but this color arrangement doesn't make sense, especially since the overall theme of MSE is blue.


If $f(x)=x^{n-1}\log x$, then the $n$-th derivative of $f$ is equals?


I am working on a program using a JPanel to show a block of text,buttons,etc. and I am trying to set a JPanel equal to another one that i created but its not doing anything. Ignore my buttons and crap.  I have the panel declared publicly       public JPanel panel;   And Here is its stuff...       panel = new JPanel();     panel.setBackground(PanelColor);     panel.setBounds(0, 93, 594, 478);     contentPane.add(panel);     panel.setLayout(null);   I want to make it so when i hit a button (in this case: btnKinematics) it changes a the panel to a different class i have called KinematicsPanel.java      btnKinematics = new JButton("Kinematics");     btnKinematics.setFont(ButtonFont);     btnKinematics.setFocusPainted(false);     btnKinematics.setBorder(compound);     btnKinematics.setBackground(Color.WHITE);     btnKinematics.addActionListener(new ActionListener() {         public void actionPerformed(ActionEvent arg0) {              highlite(btnKinematics);             panel = new KinematicsPanel();             panel.setBackground(Color.WHITE);         }     });     btnKinematics.setBounds(14, 60, 130, 23);     contentPane.add(btnKinematics);   Thanks   UPDATE: FIXED  I made some changes and this worked      contentPane.remove(panel);     contentPane.add(new KinematicsPanel());     contentPane.repaint();   thanks


I'm trying to update bash on our Red Hat Enterprise Linux Server release 5.6 server. But it won't find an update later than "3.2-24.el5". I've check and it is vulnerable for the shellshock vulnerability. I've done yum clean-all, yum update bash, yum reinstall bash. But it always comes back to just version "3.2-24.el5".  Can anyone help?  Thanks


so i was working on an aircraft [ tejas mk2 ] i faced a problem while making the canopy , iwant it to be exactly like this  but i ended up like this well i know it looks funny but yah i am an intermediate blender user ,what i wanted is a glass material that has such type of coulourish reflection as well as clear at the same time. soo.... please help me out , picture of the node settings would be much appreciated . cheers! edit : here is my current progress


Are all equiangular odd polygons also equilateral?

In standard Euclidean geometry, are all equiangular polygons with an odd number of sides also equilateral?  It is easy to prove that all equiangular triangles are also equilateral using basic trogonometric rules.  On the other hand, it is easy to conceive of an equiangular quadrilateral that is not equilateral, i.e. a rectangle.  Extending this further, I can easily conceive of an equiangular hexagon that is not equilateral, but I haven't been able to visualize an equiangular pentagon that is also equilateral:    Is this true that all equiangular polygons with an odd number of sides also equilateral? If so, is there a straightforward way to prove it? If not, is there a counterexample, an equiangular polygon with an odd number of sides that is not equilateral?


Convenient way to enable/disable Hyper-V in Windows 8

I really like the Hyper-V support in Windows 8, however, there are some situations in which I need to disable Hyper-V in order to run some apps which don't like to be executed even in the root partition of the virtualized environment. What I've been currently doing is disabling the feature completely from the "Add or remove windows features" dialog and restarting, enabling it again when needed. I would like to know if there's any better way to do this that comes to mind, it could even be a shortcut that i could double-click and will actually add or remove the feature for me and restart (I guess this may be possible with a PowerShell script).


CSS prev next button show at middle of image

Can anyone please tell me How can I show the icon in the middle of the image left and right side?   I tried many solutions but they not worked.    .slide {   display: inline-block;   font-size: 16px;   line-height: 20px;   padding: 7px 4px;   margin: 5px;   cursor: pointer;   height: 32px;   width: 32px;   background-color: #2874f0;   border-radius: 50%;   color: #fff;   text-align: center; }  .image {   height: auto;   width: auto;   max-height: 350px;   max-width: 100%;   display: block;   margin: 0 auto; }
   >      <


no partitions grub error from a dual boot from windows seven after deleting the Ubuntu partition

I deleted the Ubuntu partitions from window seven then I restarted the machine but it wont start up but I cant get back to windows seven.Instead I get a no partition grub rescue> error.I cant even get to the bios options because when I immediately switch on the computer I get the error window.I can't do anything.I deleted the partition because I wanted to uninstall it from the dual boot the install it in a virtual box inside windows.The problem is that when I switch on my Toshiba satellite laptop I immediately get the error that there is no such partition grub error.I can't do anything but just look at the no such partition grub rescue on the black screen.


So today I was completing a few quests and after I cleared a dungeon out i wanted to trade with my follower but he wasnt there!I checked the WHOLE dungeon and no sign of him.I also dont have any quest which makes you have another follower.Also if I try to recruit another follower it just says I already have one.  Also im on PC and my follower was called Stenvar.I have tried the prid 000B998C moveto player command and it doesnt work.


Let n be a natural number. Prove that if 2^n -1 is prime, then n is prime.  I have considered proof by contradiction, as well as writing the converse and contrapositive of the statement out, but still cannot seem to come up with a proof.  Any help is appreciated


I just bought a Toshiba L75D-A7283 laptop. It has an AMD Radeon HD8330 graphics card in it. Windows 8 is awful, so I figured I would give Linux a try before installing Windows 7.  I'm clueless when it comes to Linux, so anybody know why on this laptop it won't load the GUI but stays at the command line? Also it wouldn't load the GUI off the CD when selecting Try Ubuntu before installing.


Some time ago I saw a documentary in which they said that to have the experimental certainty of the existence of a string we would need a particle accelerator with the same diameter of the milky way. Now such a thing seems to me (as a layman) asymptotically out of the possibilities of advanced civilizations to accomplish.  Is this the only way to test beyond doubt the veracity of this theory or there are other sub-evidences that could either prove or disprove string theory?


Determine all integers $x $ and $ y$ such that $|2^x − 3^y| =1$

I am having trouble solving this problem:     Determine all integers x and y such that  $|2^x − 3^y| =1$   I would think that the only solutions to it is $x = y = 1$.  How can I show that there is no other solutions?  If there are other solutions, how can I find all the solutions?


Intro to Geoprocessing Scripting with Python for ArcGIS?

Can you point me to any recommended online resources where i can learn the fundamental basics of geoprocessing scripting and the different modules/python has available for an ArcGIS environment.   I have tried querying the web, but most of the time it links to me to ESRI's geoprocessing training course which I have been trying to get into through my job.


What do you call a person, who needs to stay active in order to feel comfortable?

There are some people, who always need to do something. They can't just sit and relax. If they are on the job, they constantly try to change something (e. g. propose new approaches to existing tasks). If they go on vacation, they visit all possible places.  These people are mentally healthy, even though sometimes you may suspect them having ADHD or being in a maniac phase of manic-depressive disorder.  Note that most of the time their active nature is beneficial (stuff is get done, innovation happens), but can also have negative consequences (e. g. they may bully everyone to start a project at work, which doesn't make sense economically).  Also, they are very active not because they have to, but because it seems to be part of their nature.  What do you call such people?  In Russian there is an idiom of people having an awl in the anus (шило в попе), which makes it hard for those guys and gals to sit still. I'm looking for something similar in English.


Command will run in shell but throws unexpected EOF error in cron

I am trying to run the following in cron to back up a server every morning at 4am:  0 4 * * * dump -0uan -f - / | gzip -2 | ssh -c blowfish user@server dd of=/backups/`hostname`_`date '+%m-%d-%Y_%k%M%S'`.dump.gz   Running the command on it's own from the shell works fine. Usually when this happens the problem is due to paths, so I tried adding full paths in cron:  0 4 * * * /sbin/dump -0uan -f - / | /usr/bin/gzip -2 | /usr/bin/ssh -c blowfish user@server /bin/dd of=/backups/`hostname`_`date '+%m-%d-%Y_%k%M%S'`.dump.gz   and still no luck. I checked the system log and saw this:  /bin/sh: -c: line 0: unexpected EOF while looking for matching ``' /bin/sh: -c: line 1: syntax error: unexpected end of file   The same error occurs with and without paths specified. Should be a pretty simple command. Is cron executing this differently than it is written?


Windows 8  I scanned and fixed an external usb drive and lost an excel file  The file did not want to open as it had the following message : Excel cannot open the file ... because the file format or the file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file  can anyone help?


Can't install libpng12 due to usrmerge. Can't run PacketTracer without it

I need libpng12 because of PacketTracer.  Is there a workaround without installing it? Is it safe to remove usrmerge?  dpkg: regarding libpng12-0_1.2.50-2+deb8u3_amd64.deb containing libpng12-0:amd64:  usrmerge conflicts with libpng12-0 (<< 1.2.54-4~)   libpng12-0:amd64 (version 1.2.50-2+deb8u3) is to be installed.  dpkg: error processing archive libpng12-0_1.2.50-2+deb8u3_amd64.deb (--install):  conflicting packages - not installing libpng12-0:amd64 Errors were encountered while processing:  libpng12-0_1.2.50-2+deb8u3_amd64.deb   Edit: Just wanna plug  so that installing it in the future won't be such a hassle anymore for newer users (hopefully) who aren't experienced in troubleshooting on Linux.


This is what I am getting when I tried installing Latex. Can you please help me fixing these issues $ sudo apt-get install texlive-full Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  gsettings-desktop-schemas : Breaks: mutter (< 3.31.4) but 3.28.4-0ubuntu18.04.2 is to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.


How to apply Kalman Filter for Cleaning Timeseries Data effectively without much optimization?

Someone gave me a tip to use kalman filter for my dataset. How time intensive is it to get a good kalman filter running, compared to simple interpolation methods like df.fillna(method="")  which takes basically no effort. If one or two iterations is enough to get useful results, which come very near the real missing value, then I am willing to take the effort to implement it. (Dataset length 100.000 up to 200mio rows) If it needs to be optimized like a Neural Network itself which can be costly in terms of time, isnt it better to simply use an LSTM?


how can i insert into 2 table at the same time ( java , jsp , servlet )

I have 2 table is USER and USER_CUSTOMER and I want to write a insert query in DAO class to create a new user but don't know how.    Anyone have a good idea or have a link to solve this problem please help


Root access that can't change root password?

We are having a little problem on a server. We want that some users should be able to do e.g. sudo and become root, but with the restriction that the user can't change root password. That is, a guarantee that we still can login to that server and become root no matter of what the other users will do.  Is that possible?


How can we iterate through an array of integers when we do not know the size of the array?

counting sort implementation:   The have used the below for loop to iterate through a string -  char arr[] = "geeksforgeeks";  for(i = 0; arr[i]; ++i)    ++count[arr[i]];   From google search I could understand that this condition implicitly evaluates to arr[i]!='\0'. Have I understood it correctly ? If I were to use a similar for loop to iterate through an array of integers, would it evaluate to arr[i]!=0 ?   Or is there any better way to iterate through an array of integers when we do not know its size. I am a beginner and please try to provide suggestions which do not involve advanced data structures in C.


Error with numeric class in GLM with Poisson distribution

I am trying to run a GLM with a Poisson distribution. All my variables Y and X belong to the numeric class. When I run the GLM I always see this warning: There were 50 or more warnings (use warnings() to see the first 50) with this content: 1: In dpois(y, mu, log = TRUE) : non-integer x = 45.084920  2: In dpois(y, mu, log = TRUE) : non-integer x = 5.113924  3: In dpois(y, mu, log = TRUE) : non-integer x = 52.057026  4: In dpois(y, mu, log = TRUE) : non-integer x = 1.196172  5: In dpois(y, mu, log = TRUE) : non-integer x = 22.456140  6: In dpois(y, mu, log = TRUE) : non-integer x = 0.741133  7: In dpois(y, mu, log = TRUE) : non-integer x = 54.296875  8: In dpois(y, mu, log = TRUE) : non-integer x = 8.907789  9: In dpois(y, mu, log = TRUE) : non-integer x = 13.480779  ...  If I turn my variables from numeric to integer the alarm no longer appears, but I noticed that in this way all the data is rounded to integer values. In this case, my data would lose a lot of information and so I would run a GLM with the original data in numeric class. However, if I try to run a GLM with numerical data and a GLM with integer data, I have two different outputs. I also tried to change the data by multiplying everything by 10^4, in this way I have all integer data without losing information: the result was a third different output. This is data from a behavioral experiment on some kind of bird. My dataset consists of morphological variables (weight, tarsal length, wing length, staining, etc)  and behavioural variables (number of attacks/minute, number of pecks/minute, percentage of seconds in which the individual remains in a given area, etc.). In particular, the morphological variables are X and the behavioral variables are Y. In this case, I want to see if the most aggressive individuals are also those with the best ornaments: for example, I want to see if the number of attacks/minute (Y) depends on staining (X) Being biological data, it is important that they are used in original format, not rounded. I tried running a Shapiro Wilk test to see if my data has a normal distribution and also to transform it with logarithm, but in both cases the distribution was not normal. So when I ran a histogram, I realized that their distribution was very close to that of Poisson. How can I solve this problem? Thank you in advance


How to determine obsolete kernels and remove them to clean up disk space

I want to clean disk space Disk analyzer shows this graph I noticed the repetitive pattern in /lib/modules (I guess old kernel versions)   How to determine obsolete kernels?  How to remove them safely?     Already tried sudo apt autoremove and sudo apt autoclean as described ; these had no effect.   edit - why differs my question from the suggested duplicate: A simple solution like the one-liners I already tried would be nice, as I prefer a "user-friendly" way to work with my computer instead of using cryptic terminal-commands


Why does the Statistics community publish in journals while the Machine Learning community presents at conferences?

I got my Bachelor's degree in Statistics and I'm starting graduate school to study Computer Science (CS) with an emphasis on Data Mining. One of the big differences that I've noticed between the Statistics and the ML communities is that Statistics tends to publish in journals, while CS tend to publish at conferences.  I've heard people say that conference presentations are preferred to publishing in journals because "things move so fast" in Machine Learning research. However, if you actually look reputable statistics journals are published very frequently.  The American Statistical Association publishes  every other month and the  is published quarterly. It looks like they both also have pretty quick turnaround times. The International Statistical Institute even has  that was started specifically as a "rapid communication research journal" that published papers monthly.  So, if presenting at conferences isn't actually faster than publishing in a credible statistics journal, how did this division between the two communities start?


Example that in general $|abc|\neq |cba|$

I tried to provide an example of group elements $a,b,c$ that shows that in general  $|abc|\neq |cba|$.     Please could you tell me if my example is correct?   Let $G$ be the dihedral group $D_6$ (the symmetries of a hexagon). Let us label the axes of symmetry with numbers $1$ to $6$ and call the corresponding reflections $F_1$ to $F_6$.  Now consider two "adjacent" reflections $F_1$ and $F_2$. Then   $$ F_1 F_2$$  is rotation clockwise by $120$ degrees and  $$ F_2 F_1$$  is roation by $120$ degrees counterclockwise.   Let $R$ be rotation by $120$ degrees counterclockwise. Then  $$ R F_1 F_2 = e$$  has order $1$ but  $$ F_2 F_1 R$$  is rotation by $240$ counterclockwise which has order not equal to $1$.


LaTeX - Different section names in TOC from body

Sorry if this question already appears elsewhere, I couldn't find it.  Is there a way to label a section in the text but give it a different name in the table of contents?  I have very long section titles but would like to give them nicknames in the TOC. I tried using \section*{A} then \addcontentsline{toc}{section}{B} but this removes the numbering of the section from the body of the text.  I'm very new to LaTeX so sorry if this is an annoying question!


Solid State Drive is full within less than two hours

I have a custom-made PC. I've used it for a long time and it has served me well. I was recently working with it, composing some music. The SSD (An ADATA SP550 has 222GB of space) was okay, it had more than enough space left. After around 2 hours of composing using Ableton Live, I checked my file system, and to my surprise, there was no space in my computer. Literally, no space, not even one bit left (I checked that). There is nothing I did which I think could have caused this problem. Alarmed, I purged the cache of programs like After Effects and freed around 20GB of space, emptied my recycle bin, ran some virus scanners, and tried to fix the problem. After less than an hour, I checked again and 10GB were gone from my hard drive. I've been continually checking since then and I have witnessed how continually the available space shrinks dramatically within a matter of minutes. What could be causing this alarming situation?


Tips for earning currency on Clash of Clans

I was trying to train my troops on Clash of Clans but I didn’t even have enough money to get one troop. When I joined the clan they kept on battling me and since I wasn’t very good they beat me every time so now that I left the clan I have no money left so can you help me with tips on getting more money?


Using media queries in Lightning component

I am using style attribute to use media queries in lightning components something like this:  <style>   .legendBox {     background: none!important;     min-height: 50px;     padding: 5px 0px;     position: absolute;     width: 90%!important;     left:9%;     margin-top:-15.25%!important;     border:0px!important;   }    .bootstrap-sf1 .pre-scrollable {     max-height:none!important;                   overflow:none!important;   }  </style>   My question is how to use these media queries in css section of lightning component. If possible please suggest the method as I am trying to submit the code for security review. Will it fail there?


Windows EFS encryption + password protection?

I would like to encrypt files / folders in Windows with EFS. In addition — because EFS alone still leaves the files / folders unprotected in case an adversary managers to access my Windows profile — I would like to password-protect those files / folders. But how? On my own, private PC, where I can create any number of (administrator and of course normal) users. I thought of EFS-encrypting the according files / folders under another user of mine, then switching again back to my default user account where I'd now of course be excluded from access to those files / folders. From the other user (used for encryption), however, I imported the EFS certificate into my default user account to regain access. But to no avail: I still I couldn't open those files. Please tell me: is there a way to achieve what I tried to do with (preferrably native) Windows tools like EFS + certificates or other solutions (excluding  Bitlocker, which is only good to encrypt whole drives >30GB)? And possibly in an easier way than I described, e.g. like transferring access to another (administrator?) user of mine which subsequently requires other users to enter a password to open if that's possible way to go? Or anything else, please? If not Windows-native, then at least available from the File Explorer context menu?  Bonus question: although I was not able to open the above-mentioned files / folders, I was very well able to delete them. I imagine that if the other user had actually been someone else this might be a disaster for him — is there a way to prevent unauthorized users from deleting files? I mean I know related permissions can be set in the Windows file properties, but afterwards it only took me (using my default user without read access) to "take ownership" of the file again, and although I still I couldn't read it, I could very well delete it...   Info just in case it surprisingly matters: the used (EFS encryption-) test files and EFS certificate im-/export happened via a Bitlocker-protected USB drive used under both test user accounts).


yeah i know that the  sample rate is low, i increased it to 300 and it still was noisy, i think it has something to do with the indirect light, right?   I dont know if i need to give more info, im quite new to blender, like, a week new.  The project file is here:


Action Function Param Not Passing to Controller

EDIT: I needed to put a ReRender, but why?    Trying to pass an action function param to the VFP's custom controller. The value is not passing as passedVariableString returns null on the debug. Where am I going wrong?  Initiated in between script tags on VFP:  var variable = 'some text here'; launchActionFunction(variable);   On same VFP:  <apex:actionFunction action="{!launchActionFunction}" name="launchActionFunction">        <apex:param name="passedVariable" value=""/> </apex:actionFunction>   On Controller  public void launchActionFunction()     {     string passedVariableString =      system.CurrentPageReference().getParameters().get('passedVariable');     system.debug(passedVariableString);     }


Is it possible to earn more than 100 lollipops per second?

I have pumped my lollipop rate to 100/s, but it took a long time to go from 99 to 100. Is it even possible to get higher or should I stop?


I add a PPA but the software does not show up in Ubuntu 11.10 updates nor Software Centre

Every time I add a PPA I cannot see the package I'm trying to install. I suppose I must be doing something wrong! So here's my latest effort:  In a Terminal I typed:  sudo add-apt-repository ppa:jeromerobert/misc   and that seemed to work correctly  Then I typed:  sudo apt-get update   But when I go to Synaptic or Software Center the application I want to install is not there. Could someone please tell me what I'm doing wrong?