After I make an exe file, there are many files such as .pyd that my exe depend on them.. I want to make a program with only one exe file which will be handie.. please help me

I thought I heard that  was able to do this, but I never figured it out.  Has anyone successfully done this?  Can I see your setup.py file, and what command line options you used?  Basically I'm thinking of it giving me a single executable file that does something like unzips itself to maybe /temp and runs.


Currently when you look at NYSE: GME (GameStop Corp.), according to  the company has a short interest of 136.56% since 09/15/20. How exactly is this possible? Is this just a faulty data point, or does the calculation take into account other derivatives like unexercised options?

Is it possible for a single share of stock to be shorted multiple times? Concrete example: Imagine we have five people with the following motivations: Person A owns a share of company ABC and wants to lend it out to collect interest.   Person B wants to short one share of company ABC.   Person C wants to own one share of company ABC and lend it out to collect interest.   Person D wants to short one share of company ABC.   Person E wants to own one share of company ABC.    The following then occurs (in order): Person A lends their share to Person B   Person B sells their share to Person C   Person C lends their share to Person D   Person D sells their share to Person E    This would result in 3 long positions of one share each, and 2 short positions of one share each, all based on one "real" share. If the above is allowed, you could imagine this occurring infinitely, allowing unlimited long and unlimited - 1 short positions, so long as the net equaled one long share. Is this possible? Are there any regulatory or procedural systems in place to prevent the above from happening?


I did Shift + L to select objects with the same default material, but now how do I apply a material to all of those?  It will only apply a material to the original one I wanted to compare the other objects with.

I saw a video where the person copied a material from one object to another (Cycles).  How can I accomplish this?


This is the code I got on stackoverflow also         but I want to enhance it to make not case sensitive         or should I change the \\b because I think it's a match symbol.        What should I do?   function filter() {     var regex = new RegExp('\\b' + this.value);     var $els = $lbs.filter(function () {         return regex.test($(this).text());     });     $lbs.not($els).hide().prev().hide();     $els.show().prev().show(); };  input.keyup(filter).change(filter);

I'm trying to get a case-insensitive search with two strings in JavaScript working.  Normally it would be like this:  var string="Stackoverflow is the BEST"; var result= string.search(/best/i); alert(result);   The /i flag would be for case-insensitive.  But I need to search for a second string; without the flag it works perfect:  var string="Stackoverflow is the BEST"; var searchstring="best"; var result= string.search(searchstring); alert(result);   If I add the /i flag to the above example it would search for searchstring and not for what is in the variable "searchstring" (next example not working):  var string="Stackoverflow is the BEST"; var searchstring="best"; var result= string.search(/searchstring/i); alert(result);   How can I achieve this?


Let $R$ be a ring with no zero divisiors such that for all $r,s\in R$ there exist $a,b\in R$ not both zero with $ar+bs=0$.   If $R=K\oplus L$ then $K=0$ or $L=0$. if $R$ has an idendity then any two bases of free $R$ module $F$ have the same cardinality.   I am done with first statement, I guess that  I will use first part to  show the second one.  I need help in second one.  Thanks.

The following is exercise number 10 in Hungerford's Algebra, page 190:  Let $R$ be a ring with no zero divisors such that for all $r, s \in R$ there exist $a, b \in R$, not both zero, such that $ar + bs = 0$.  a) If $R = K \oplus L$ (module direct sum) then $K = 0$ or $L = 0$  b) If $R$ has an identity, then $R$ has the invariant dimension property.  I have proved part a), but I'm having difficulty with b). I realize that it suffices to show that $R^m \cong R^n$ implies $m = n$, but I can't seem to use part a) to conclude this.


I have encountered this error in eclipse, attempting to connect to my database.  I have looked at these suggestions:      However they all seem to suggest including derbyclient.jar into build path for your project, which I have.   java.lang.NoClassDefFoundError: org/apache/derby/jdbc/ClientDriver     at datasource.DBConnection.getDBConnection(DBConnection.java:38)  my database connection:  private static final String DB_CONNECTION = "jdbc:derby://localhost:1527/database;create=true";  private static Connection getDBConnection(){    try {          DriverManager.registerDriver(new org.apache.derby.jdbc.ClientDriver());          Connection dbConnection = DriverManager.getConnection(                         DB_CONNECTION, DB_USER,DB_PASSWORD);         return dbConnection;      } catch (SQLException e) {          System.out.println(e.getMessage());      }     System.out.println("Connection problem");     return null;  }

I am getting a NoClassDefFoundError when I run my Java application.  What is typically the cause of this?


Let $ABC$ be a triangle in which $CA = BA$  and $∠CAB = 90^\circ$. Suppose $M$ and $N$ are points on $BC$ such that $CN:NM:MB=3:5:4$. How do I prove that angle $MAN=45$.

Let ABC be a triangle in which $AB = AC$ and $\measuredangle CAB = 90^{\circ}$. Suppose $M$ and $N$ are points on the hypotenuse $BC$ such that $BM^2 + CN^2 = MN^2$. How do I  prove that $\measuredangle MAN = 45^{\circ}$.


I get aNullPointerException when I try to run this code:  private static Semaphore[] trackSemas;  for(int i=0;i<9;i++){             trackSemas[i] = new Semaphore(1,true);         }   Why doesn't this bit of code get a NullPointerException?

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


Let $S^{d-1}$ be the unit sphere (centered at $O$) in $d$ dimensions. One can show that when $d=3$, for fixed $x\in S^{2}$ the area of $P(x) = \{y\in S^{2}, \angle xOy < \alpha \}$ is $2\pi(1-\cos\alpha)$. What is the analogous result in $d$ dimensions? Any help appreciated.

According to , let the sphere have radius $R$, then the surface area a spherical cap of height $h$ and base radius $a$ is given by $$S=2\pi Rh=2\pi(a^2+h^2).$$  What is this value for an n-dimensional hypersphere? If it helps simplify the problem we can assume $R=1$ and $a=0.5$.   Many thanks.


I recently upgraded to Ubuntu 12.04 and after doing some updates and such my application launcher and title bars (for window dialogues) are missing. Basically the entire Unity GUI is missing!  Not sure what happened so I installed GNOME 3 and it was missing a launcher too, but did have title bars. In addition the bar found at the top that lets you know what's open and allows GNOME extensions to be displayed is not interactive. I can't click, right click, alt + click (right or left), alt + super click (right or left) anywhere! I even installed an application menu from the GNOME site and it is not interactive either. However, since there is no way to launch applications I have to use terminal and if I minimize an app it will disappear completely.  Then I decided to try Unity 2D and it is incredibly messed up. Black background, launcher is there but icons and top bar while on desktop are completely distorted. They're not just pixelated; they're all sorts of funky colors and when I open something from Unity 2D launcher it will show it's opened in the launcher but nothing appears on my screen.  When trying to view videos on YouTube the video is distorted and looks just as Unity 2D does. Strange enough: the audio works fine, just not videos. Pictures loads, but not ads that stream video.  Any suggestions to get my launcher and the Unity GUI back? I tried reinstalling GNOME, Unity 3D, and Unity 2D from terminal. No change. Also reinstalled Unity desktop and tried resetting it: nothing happened.

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


This a may be an inconvenient question, but I am needing help in the understanding the top answer given in this question:  My main problem is that I can’t understand why or how some passwords where removed twice?

I need to calculate the possible combinations for 8 characters password. The password must contain at least one of the following: (lower case letters, upper case letters, digits, punctuations, special characters).  Assume I have 95 ascii characters (lower case letters, upper case letters, digits, punctuations, special characters).   lower case letters = $26$ upper case letters = $26$ digits = $10$ punctuations & special characters = $33$   The general formula for the possible passwords that I can from from these 95 characters is: $95^8$.  But, accurately, I feel the above formula is incorrect. Please, correct me. The password policy requires at least one of the listed above ascii characters. Therefore, the password possible combinations = $(26)*(26)*(10)*(33)*(95)*(95)*(95)*(95)$  Which calculation is correct?  EDIT: Please, note that I mean 8 characters password and exactly 8. Also, There is no order specified (i.e. it could start with small letter, symbol, etc.). But it should contain at least one of the specified characters set (upper case, lower case, symbol, no., etc.).


I don't know how I changed this, after a restart I found this home folder on the desktop. I don't want it there - how do I remove it? Left click does not show an option to delete it.  Here's a screenshot:

I've googled quite a bit but nothing I've found works. I just want to display the Trash, Home folder, Computer etc icons on my Desktop in Ubuntu.  The closest I've come is installing dconf-tools, running it, going to org -> gnome -> desktop -> background and checking show-desktop-icons then org -> gnome -> nautilus -> desktop and checking the icons I want to show.  Nothing happens.  I've also tried looking in compizconfig-settings-manager and gconf-editor but can't find anything there.  Ideas?


I am writing a loop in bash where I want to include one variable in another variable:    printf "Number of volumes to add: "   read -r num_volumes   for volume_number in "$num_volumes"   do     vol_id_{$volume_number}="create_volume"   done   Is this the correct syntax to use?

I am trying to print a simple value for $AR1_p1 but the variable $i is not evaluating. for i in 1 2 3 4 do     AR1_p1=22     AR1_p2=23     AR1_p3=24     AR1_p3=25     echo $AR1_p$i done   It's like concatenating dynamically. Any suggestions on how to fix this?.


Can we paint $\mathbb{R}^2$ with two colors (say, black and white) so that any horizontal line pass through countable black points and any vertical line pass through countable white points?    Update. I was amazed that this is a classical problem! Actually what I wanted to do is using set theory to prove that there exist incomparable Turing degrees.

The problem is to prove the following equivalence:  $$2^{\aleph_0}=\aleph_1 \iff \exists\ A,B\in\mathbb{R}^2:\\ \textrm{a)}A\cup B=\mathbb{R}^2 \\\textrm{b)}\ \forall\ \textrm{lines } l\ \textrm{parallel to x-axis, } |A\cap l|\leq\aleph_0 \\\textrm{c)}\ \forall\ \textrm{lines } l\ \textrm{parallel to y-axis, } |B\cap l|\leq\aleph_0$$  I think I know how to prove "$\impliedby$":  Let's assume the RHS and that $2^{\aleph_0}\geq\aleph_2$. Now let's take a sequence $\langle x_{\alpha}:\ \alpha<\omega_1\rangle$. Since $\bigcup_\limits{\alpha<\omega_1}|B\cap x_{\alpha}|\leq \aleph_1\cdot\aleph_0=\aleph_1$ there is such a $y$-coordinate that neither of $(x_{\alpha},y)$ is in $B$. But hence we obtain $\aleph_1$ point which all lie on the same line parallel to $x$-axis. Since $A\cup B=\mathbb{R}^2$ they all must be contained in $A$ $-$ a contradiction as $A$ has at most countably many of those points.  But what about the other implication? Do I contruct these sets by induction? Over all lines or something else? I haven't come up with anything yet, perhaps you could help me.


I wanted to reinstall my system, because I got frequent error messages while booting. However, it did not work. I can "Try Ubuntu" but get error messages in the installation menu.  Apparently, the old OS was only partially removed. Whe I try to format the  partition, I get the following error message:  Der Versuch, ein Dateisystem vom Typ vfat auf SCSI1(0,0,0),Partition#1(sda) als /boot/efi einzubinden, ist fehlgeschlagen. Sie sollten die Partitionierung im Partitionierungsmenü fortsetzten.   Translation:   There was an error trying to mount a file system of the type vfat on SCSI1(0,0,0),Partition#1(sda) as /boot/efi. You should continue the partitioning in the partitioning menu   I can skip this error but during the installation I see the following warning in the terminal, which I assume is caused by the previous error.  /usr/lib/ubiquity/fronted/gtk_components/nmwidgets.py:18: Warning Source ID 7804 was not found when attemping to remove it. GLib.source_remove(self.timeout_id)   I also get errors when I try to install Windows.  Can anyone help me install my system?

I'm trying without success to install Ubuntu 14.04 on my Toshiba Portege.   I want to remove Windows 7 and I tried with the automatic partitioning from the USB installer (I found that compared to previous Ubuntu's version it is getting more complicated).   When it finally started installing (first time without any bar of progress, very annoying, then I shut down and tried again and the progress was shown), it is stack on   Creating ext4 file system for / in partition #2 of SCI1 (0,0,0) (sda)   and in the details there are many errors like  /usr/lib/ubiquity/frontend/gtk_components/nmwidgets.py:18: Source ID 86689 was not found when attempting to remove it Glib.source_remove(self.timeout).   I let it run all the night but it is still there.  I also got the error:  The attempt to mount a file system with type vfat in SCSI2 (0,0,0), partition #1 (sda) at /boot/efi failed You may resume partitioning from the partitioning menu.


If we create2 work flows( field update)on same object which workflow rules will exceute first ?

If I create two workflow rules, the first being  Whenever a case is opened, set Example Case Field to A   and the second being  Whenever a case is opened, set Example Case Field to B   how does Salesforce determine the order of execution?


As you can see my query, this is the working one  SELECT m.MerchandiseId, m.MerchandiseName, createdAt =  MAX(i.CreatedAt) FROM Inbox i INNER JOIN [User] u ON i.FromUserId = u.UserId LEFT OUTER JOIN Merchandise m ON u.MerchandiseId = m.MerchandiseId  OR i.ToMerchantId = m.MerchandiseId WHERE i.ToCompanyId = 10 OR i.FromCompanyId = 10 GROUP BY m.MerchandiseId, m.MerchandiseName     What if i want to SELECT one more field as i.InboxMessage with the Last record of each group?  SELECT m.MerchandiseId, m.MerchandiseName, i.InboxMessage, createdAt =  MAX(i.CreatedAt) FROM Inbox i INNER JOIN [User] u ON i.FromUserId = u.UserId LEFT OUTER JOIN Merchandise m ON u.MerchandiseId = m.MerchandiseId  OR i.ToMerchantId = m.MerchandiseId WHERE i.ToCompanyId = 10 OR i.FromCompanyId = 10 GROUP BY m.MerchandiseId, m.MerchandiseName   I've tried some ways that I found in stackoverflow, but I still not manage to do it. Thousand of thanks if anyone would help on this.

I often need to select a number of rows from each group in a result set.  For example, I might want to list the 'n' highest or lowest recent order values per customer.  In more complex cases, the number of rows to list might vary per group (defined by an attribute of the grouping/parent record). This part is definitely optional/for extra credit and not intended to dissuade people from answering.  What are the main options for solving these types of problems in SQL Server 2005 and later? What are the main advantages and disadvantages of each method?  AdventureWorks examples (for clarity, optional)   List the five most recent recent transaction dates and IDs from the TransactionHistory table, for each product that starts with a letter from M to R inclusive. Same again, but with n history lines per product, where n is five times the DaysToManufacture Product attribute. Same, for the special case where exactly one history line per product is required (the single most recent entry by TransactionDate, tie-break on TransactionID.


I am not getting whole idea behind Public Key Encryption technique.  As according to fact, public key encryption method uses two keys a public key known to everyone private key known only to recipient of the message  For an instance let assume, John wants to send a secure message to Jane, He uses Jane's public key to encrypt the message. Jane then uses her private key to decrypt it.  The thing i am not getting is, as far as i know if we want to encrypt any message using a key, from that same key only we can decrypt that particular message.  But in public key encryption case both keys are different than how it is possible to decrypt the message.  Please clarify my issue and guide me through if i am going anywhere wrong in understanding the whole concept

I've always been interested in encryption but I have never found a good explanation (beginners explanation) of how encryption with public key and decryption with private key works.  How does it encrypt something with one key and decipher it with another key?


Given the set $A=\{1,2,3\}$  How many different binary equivalence relations can be formed?  Can I list all of them?  Furthermore, how will this answer change as I add more elements to the set?

Let $M$ be the set $\{1,2,3\}$. How many Equivalence relations $R \subset M \times M$ exists?  My idea is to count the disjoint partitions of M:  $K_1= \{\{1\},\{2\},\{3\}\}\Leftrightarrow\{(1,1),(2,2),(3,3)\}$  $K_2= \{\{1,2\},\{3\}\} \Leftrightarrow\{(1,1),(1,2),(2,1),(2,2),(3,3)\} $  $K_3=  \{\{1,3\},\{2\}\}\Leftrightarrow\{(1,1),(1,3),(3,1),(2,2),(3,3)\}$  $K_4= \{\{1\},\{2,3\}\}\Leftrightarrow\{(1,1),(2,3),(3,2),(2,2),(3,3)\}$  $K_5=\{1,2,3\}\Leftrightarrow K_5=M^2$  So the answer would be $5$. Is this correct? Reflexivity and Symmetry are obvious, but how can i check the right side for Transitivity?


I am travelling to Montreal from Beirut, Lebanon and transiting through Geneva, Switzerland. I am holding a Syrian passport. Do I need any transit visa in Geneva airport?

Do I need an airport transit visa through Switzerland if I have no Schengen visa? Am traveling from Cairo to Moscow via Swiss Air


I need to remove the face inside this cylinder intersecting with my cube. I've tried to use the knife, project knife with a circle, tried adding a boolean and union/intersect.. nothing does it. The cylinder is scaled down towards the bottom and there is also an angle to the cube. still not working. Please help ! and all those object are currently a single piece.

I'm trying to find a simple way to create vertices where two objects intersect and delete the leftover internal planes + then join the meshes so that I have one hollow mesh to sculpt. The reason I need to know this is that on my first sculpt I just joined the meshes, but it didn't create vertices at the intersecting points so when I went to sculpt it just overlapped the meshes as you can see here in the neck.  Here is what I am working on now, it needs to be 1 hollow mesh


All of a sudden when I insert a picture into a page, it shows an edit and a delete button above the image to the end user.  These buttons take you to the default page.  Also, now when I edit a page from the edit button at the top of each page and save, I get the following type of message after a lengthy wait.  Fatal error: Allowed memory size of 356515840 bytes exhausted (tried to allocate 523800 bytes) in /data/www/luna/sites/all/modules/token/token.module on line 767   I can edit and save if I select the page under Content.  See

I have a issue with my Drupal installation, for example:   when I enable or disable the modules, It redirects me to a blank page, when I create a new content type and save it, redirects me to a blank page, when I add a new view and save it, it redirects me to a blank page, when I try to clear the cache, it redirects me back to a blank page, or in similar cases.   Basically all the confirmation pages redirect me to a white screen. When I refresh it again, it shows me the page. I tried to increase the PHP memory value but it doesn't help.  Are there any other solutions for this?  The error which I'm having:      Fatal error: Allowed memory size of 100663296 bytes exhausted (tried to allocate 8192 bytes) in sites/all/modules/views/plugins/views_plugin_localization_none.inc on line 1


I have a table which has checkboxes which get generated after a user imports files. The checkboxes are generated dynamically.      $("input[name='child_user_id_fk[]']").change(function(){         alert("test");         $(this).closest("tr").toggleClass("checked", this.checked);     });   This will work on any checkbox that was a part of the page when it were generated, but just not the ones generated with JQuery. How can I get this working?

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


I have installed sharepoint 2013, my central Administration is not opening properly images and CSS are missing.Help me to solve the issue  Thanks

After installing SharePoint 2013. I had open the central admin page, But it does not have any image and CSS style.


I use calloc, I've read that, calloc internally calls new handler, so what should I go for?   Should I use new operator(which allocate fast) or calloc(which can allocate and initialize memory as well)?

I see in C++ there are multiple ways to allocate and free data and I understand that when you call malloc you should call free and when you use the new operator you should pair with delete and it is a mistake to mix the two (e.g. Calling free() on something that was created with the new operator), but I'm not clear on when I should use malloc/ free and when I should use new/ delete in my real world programs.  If you're a C++ expert, please let me know any rules of thumb or conventions you follow in this regard.


I was wondering if it is possible to install the official stock android operating system from google without the customization of the manufacturer like Touch Wiz on Samsung Galaxy Ace 3 s7270, is there a way to do this

Is it possible to flash a smartphone like the Samsung Galaxy SIII or an LG Optimus 4X with a vanilla Android ROM like the one that has been flashed on Galaxy Nexus or Motorola phones (I think)?  I am asking because manufacturers like Samsung, LG, HTC tend to make ROMs for their smartphones and tablets with preinstalled launchers like Touchwiz or HTC Sense. They explain their decision by saying that they want to make their devices to look unique against their rival devices. The problem is that Android updates for their phones and tablets get delayed and there are incidents in which some devices - which are more than capable of running the upcoming version of Android - fall way behind or never get updated at all.   So, what I am basically asking here is if there is a way to install vanilla Android, excluding CyanogenMod or any other modified vanilla ROMs, on an Android based smartphone?


It's a question that was bothering me for some time. In special relativity one can consider the "twin paradox", where one twins leaves earth and returns, staying young while the twin left behind grows older. This is not a paradox because the twin in the spaceship accelerates to change his direction when turning back- therefore he is not in an inertial frame.  However, in a universe with the geometry of a flat torus, one can go "around" the universe and return to earth without accelerating or experiencing any intrinsic curvature of the universe. In this situation the paradox rises again: which twin is older and which one is younger, considering that both twins' frames of reference are valid?

Take the following gedankenexperiment in which two astronauts meet each other again and again in a perfectly symmetrical setting - a hyperspherical (3-manifold) universe in which the 3 dimensions are curved into the 4. dimension so that they can travel without acceleration in straight opposite directions and yet meet each other time after time.  On the one hand this situation is perfectly symmetrical - even in terms of homotopy and winding number. On the other hand the Lorentz invariance should break down according to , so that one frame is preferred - but which one?  So the question is: Who will be older? And why?  And even if there is one prefered inertial frame - the frame of the other astronaut should be identical with respect to all relevant parameters so that both get older at the same rate. Which again seems to be a violation of SRT in which the other twin seems to be getting older faster/slower...  How should one find out what the preferred frame is when everything is symmetrical - even in terms of GRT?  And if we are back to a situation with a preferred frame: what is the difference to the classical Galilean transform? Don't we get all the problems back that seemed to be solved by RT - e.g. the speed limit of light, because if there was a preferred frame you should be allowed to classically add velocities and therefore also get speeds bigger than c ?!? (I know  is only a local theory but I don't understand why the global preferred frame should not 'override' the local one).  Could anyone please enlighten me (please in a not too technical way because otherwise I wouldn't understand!)  EDIT Because there are still things that are unclear to me I posted a follow-up question:


How would I show that $$f(x,y) = \frac{2xy}{x^2 + y^2}$$  is not differentiable at the origin?   Is it enough to show that as the function tends to the origin along the paths $y = x$ and $y=2x$ that we get different limits and hence the function is not continuous?

$$f(x,y) = \left\{\begin{array}{cc} \frac{xy}{x^2+y^2} & (x,y)\neq(0,0) \\ f(x,y) = 0 & (x,y)=(0,0) \end{array}\right.$$  In order to verify if this function is differentiable, I tried to prove it by the theorem that says that if $\frac{∂f}{∂x}$ and $\frac{∂f}{∂y}$ exist and are continuous at the point $(x_0,y_0)$, then the function is differentiable at this point. So I did:  $$\frac{\partial f}{\partial x}(0,0) = \lim_{h\to 0}\frac{f(0+h,0)-f(0,0)}{h} = 0$$ $$\frac{\partial f}{\partial y}(0,0) = \lim_{h\to 0}\frac{f(0,0+h)-f(0,0)}{h} = 0$$  so we have that the partial derivatives at point $(0,0)$ is $0$. Now, if we take the derivative at $(x,y)\neq (0,0)$ and then take the limit of it as $(x,y)\to(0,0)$, we can see if the derivatives are continuous or not. So here it is:  $$\frac{\partial f}{\partial x}(x,y) = \frac{y(y^2-x^2)}{(x^2+y^2)}$$  but   $$\lim_{(x,y)\to(0,0)} \frac{y(y^2-x^2)}{(x^2+y^2)} $$ does not exist (by wolfram alpha... but can anybody tell me an easy way to prove this limit does not exist? easier than taking the limit in different directions?), therefore the derivative is not continuous at $(0,0)$, so we can't say $f$ is differentiable at $(0,0)$, but for $(x,y)\neq (0,0)$ the function is continuous, as it is a quotient of continuous functions. So $f$ is at least differentiable at $(x,y)\neq (0,0)$.   Now, to verify differentiability at $(0,0)$ I think we must use the limit definition of differentiablity: A function is differentiable at $(0,0)$ iff: $$\lim_{(h,k)\to (0,0)} \frac{f(0+h,0+k)-f(0,0)-\frac{\partial f}{\partial x}(0,0)-\frac{\partial f}{\partial y}(0,0)}{\|(h,k)\|} = 0$$  Let's calculate this limit:  $$\lim_{(h,k)\to (0,0)} \frac{f(0+h,0+k)-f(0,0)-\frac{\partial f}{\partial x}(0,0)-\frac{\partial f}{\partial y}(0,0)}{\|(h,k)\|} = \\ \lim_{(h,k)\to (0,0)} \frac{\frac{hk}{h^2+k^2}}{\sqrt{h^2+k^2}} = \\ \lim_{(h,k)\to (0,0)} \frac{hk}{(h^2+k^2)\sqrt{h^2+k^2}}$$  which I think, it's a limit that does not exist, therefore the function isn't differentiable at $(0,0)$


I am generating my PDF document (thesis) with LuaLaTeX. Almost all of my figures are made with the  package and do not exceed 40 kB. The document is 178 pages. The size of this document is 34 MB. It is too large to upload to our library server.  Even if I exclude all non-PDF images the size does not decrease much. It decreased on the size of png images I'm using.  Is there a way to reduce the quality of the document and compress it? For example: compress all figures...

I feel that the PDFs produced by pdflatex are too huge. So for example my 50 page book with no illustrations is 500KB. I feel it should be more like 50K or even less. The .tex files together are just 40KB. Anyone knows why the final PDF is so huge and is there a way to compress it to make smaller?


Is it possible to install Ubuntu and delete Windows? I don't want to dual-boot and I'm not sure whether Ubuntu needs an OS on my computer to operate.    Ok. I have installed Ubuntu's latest version . It goes well until I move my mouse on the Desktop, then I get a broken image.

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS.  Should I do it with Wubi, or through the Live USB/DVD?  What steps do I need to take to correctly install Ubuntu?


I have a old Win XP Pro machine that I would like to install Ubuntu on and would like to know what is the best version to get as there are several releases available on Amazon, my go to store. Since this is a 2002 vintage machine I'm assuming one of the older releases is most likely to install without problems. I built this machine in 2002. It is a 32-bit, Intel P4-D845EBG2L mother board with Pentium 4, 2.2GH, Northwood 512K, Socket 478, 400MHz bus, CPU. It has 1GB of  memory, a ATI All-in-Wonder Radeon 8500DV, 64MB, DDR AGP-Retail, Video card. There are CD, DVD, Floppy and USB 2.0 drives. My goal is to learn Linux with the Ubuntu release. I have very little knowledge of Linux but have worked with Windows since the DOS days and am some what comfortable at the DOS (windows) command prompt. I admit to drinking the Windows Kool-Aid. Thanks for any assistance Greid

For a given hardware configuration, how do I find out if Ubuntu will run on it? What considerations should I take into account when choosing an Ubuntu version and  such as:    with a lighter desktop than the usual Gnome and Unity  with the even lighter LXDE desktop   Obviously Ubuntu does not run on some processor architectures. So how do I go about choosing the right version and derivate. How can I find out the minmal system requirements?


My concern is with regards to something like:  for i in range(1000000000):     ...   From a naive point of view, I assume that an array of 1000000000 integers is allocated and initialized before the loop begins, and deallocated only after the loop ends.  So I am wondering whether or not I should replace it with:  i = 0 while i < 1000000000:     ...     i += 1   But according to , a for loop is executed faster than the equivalent while loop.  So do I have to settle for this kind of trade-off, or is my assumption above wrong, and there is no significant memory impact when iterating a large range?

Apparently xrange is faster but I have no idea why it's faster (and no proof besides the anecdotal so far that it is faster) or what besides that is different about  for i in range(0, 20): for i in xrange(0, 20):


I have the following HTML code for a user to enter a question with a subject:  <form class="cf" id="question-form">
Welcome to My Website!

Enter a subject and question to get started.

                 <input type="text" name="subject" placeholder="Subject" />

                 <textarea rows="5" cols="40" name="question"                     placeholder="Question"></textarea>
              <input type="submit" class="btn" value="Submit" />          </form>   I have an text input form for the subject of the question, and I have the 'textarea' element for the question itself. I want to add an event listener to listen to the 'submit' button after both the subject form and the question forms, and handles the event before the user can enter a question. However with the following JavaScript code, the code 'listens' to the ENTER key pressed in the subject form. I want to enter some subject test, press the enter key, put some text in the question text, and then click the submit button.  var questionForm = rightPane.childNodes[1];  questionForm.addEventListener("submit", function(event) {  // do something      alert("I have been clicked");  });

How do you prevent an ENTER key press from submitting a form in a web-based application?


Ubuntu pls add a feature for this in windows and still if you not gonna do it. So it just for typing a code or just running a command not used for windows. Why Ubuntu...

Where can I send feature requests? Both for Ubuntu as a whole and individual (supported) apps?


I have written a query to find the duplicate rows in a table. It outputs duplicate pairs (e.g.    row: 1,2  after that you enounter row: 2,1)  SELECT m1.ID, m2.ID FROM AccessLog_Manual m1     INNER JOIN AccessLog_Manual m2 ON          m1.ACCESS = m2.ACCESS AND          m1.EMPLOYEEID = m2.EMPLOYEEID AND         m1.LOGDATETIME = m2.LOGDATETIME AND         m1.MORPHOACCESSID = m2.MORPHOACCESSID AND         m1.ID <> m2.ID ORDER BY m1.ID   Now I want to use this query in a delete statement, such that removing only one row of pairs. (i.e. for example row 1,2 and row 2,1, only delete 1 and let 2 non-deleted)

What is the best way to remove duplicate rows from a fairly large SQL Server table (i.e. 300,000+ rows)?  The rows, of course, will not be perfect duplicates because of the existence of the RowID identity field.  MyTable  RowID int not null identity(1,1) primary key, Col1 varchar(20) not null, Col2 varchar(2048) not null, Col3 tinyint not null


I need to travel from Paris CDG (first flight Air France, 2nd flight Delta, both cies are sky team) to Saint louis missouri via Minneapolis. During the connectiong flight from international to Domestic), Do I need to pick-up my luggage in minneapolis and immediately check-in for domestic flight, or will my luggage will go direclty to Saint-louis. If yes, is it convenient in Minneapolis (I have only 1H25 minutes stop?

I shall arrive at Washington Dulles Airport (IAD) by Emirates flight to catch a united airlines flight to Detroit after 3.5 hours. What steps shall I have to go through? Is the connection time enough? I have US F1 visa.


In The Empire Strikes Back Yoda tells Luke that:     Size matters not, judge me by my size do you?   This always led me to believe that as The Force did the actual lifting it was only the belief of the force user in question that limited their force telekinesis.  However, in the prequels a lot is made of how powerful Anakin is (which presumably means he could perform force feats which others could not). I believe there are a few instances (perhaps in older canons) where he prevented AT-ATs from stepping on him and lifted two AT-DP walkers at the same time. I think it's safe to say the "average" jedi couldn't do this!  Was Yoda being truthful when he told Luke that "size matters not" or was it more of a pep talk to convince Luke that he could lift the X-wing?

In Empire Strikes Back, Yoda  that an object's size doesn't matter and that the difficulty of levitating an X-Wing was only in his mind. If the upper limits of telekinesis are determined by belief, what's to stop a Jedi/Sith from pulling a moon out of orbit, moving an entire solar system, or splitting an atom with the Force?


Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


In all of the descriptive dictionary definitions of “emoji” I've encountered thus far (e.g. ), the plural of emoji is given an optional “s.”     plural emoji or emo·jis   In the responses to , the term is described as a Latinized version of its Japanese progenitor.   Though it doesn't follow the Latin pattern exactly (there is no emojus of which I am aware), does its Latinization lend any credence to an argument in favor of using emoji for both the singular and plural form of the noun (i.e. as a )?

As someone who has watched a lot of subtitled Japanese animation, it seems odd to hear a word such as ninja (used in the plural) in the dialogue and see it transliterated as ninjas.  It somehow seems better to me to treat ninja just like antelope, bison, buffalo, caribou, deer, elk, fish, grouse, quail, reindeer, sheep, swine, etc., which are both singular and plural.


I have a question regarding interfaces. If I have an interface Printable which has (for example) a method "print", and I create a class Book which implements the interface, I can create an object of Book in two different ways:  Book b = new Book(); Printable b1 = new Book();   I know that I can only reach the methods declared in the interface Printable if I create the object using the second method, but why do we have this option? In which cases would one want to only access the methods declared in the interface, and not be able to access the other methods that are specific to the class in question? Maybe a stupid question, but I don't understand the use of the second option shown above.

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


I have a Schengen Visa from Germany ,multi entrance for two years. Can I travel to Hungary,or Romania, direct without entering through the German border ?

In case, if I get a multiple-entry Schengen visa in one of the embassies in Ukraine, Kyiv - should my first trip be to the country which issued the visa?  Any there any requirements of this sort? Does this condition vary depending on embassy which issued the visa?  What are the possible consequences on not visiting that country first? Does it somehow depend on country where the embassy is (i.e. non-Schengen and not EU members)?


So the title explains why I'm posting. I'm a masters student in economics at a pretty prestigious university and one of the courses that you're required to take as a first year is called Math Methods for Economists. It covers topics from Calculus to Linear Algebra and Differential Equations. I really wanted an A in this class because I'm hoping to have the option of applying to a really good PhD program (although I'm not sure yet), but I got a B- in the class.  I'm pretty upset by this. I really thought I could get an A. I took Calc I and II as an undergrad and I got halfway through Linear Algebra- I dropped out because it was the last semester of my senior year and honestly I was just lazy (but I still remembered a lot of the concepts from the class).  In the class I did really quite poorly on the first exam and I do blame myself for not preparing enough for that one. I was going to drop the class and retake it in the Spring (because you have the option of taking it online with FULL internet access during the exams) but then the professor said that if you get an A on the final he'd just give you an A in the class. I was determined to use that loop hole and get that A on the final.  I spent the 5 days before the exam studying so hard- I mean every free second that I wasn't eating or sleeping- I was up until 3:00am every night studying. I don't think I've ever spent so much time preparing for an exam.  I kind of knew it was hopeless though. This professor gives insanely hard exam questions that he does almost nothing to prepare you for. As aforementioned, I have quite a bit of background in math and I have never seen math problems like the ones he puts on his exams.They're not conceptually hard to understand but he tries to trick you using the most obscure algebra techniques that even software has trouble finding a closed form solution for. I've tried plugging some of the problems into symbolab.com and multiple times I was told "can not be solved" - which I didn't even know was possible.   I ended up getting an 82 on the exam and I just think its so unfair that I have to have a B- on my transcript. I've never blamed a professor for my own grade but this is ridiculous. I know some students complained about the professor directly to the program advisor before and nothing resulted from it.  Is there anything I can do about this? Does the B- condemn me to eternal graduate school hell? I'm really just looking for some peace of mind.

When applying to a PhD program in the US, how does the admissions process work? If an applicant is weak in a particular area, is it possible to offset that by being strong in a different area?  Note that this question originated from this . Please feel free to edit the question to improve it.


A matrix A is said to be invertible if there exists a matrix $A^{-1}$ such that $A\cdot A^{-1} = I$.  Given that we find a matrix (call it $A^{-1}$) such that $A\cdot A^{-1} = I$, I'm wondering why it is enough to stop here and not check whether $A^{-1}\cdot A = I$ as well. Any hints?

If $A$ and $B$ are square matrices such that $AB = I$, where $I$ is the identity matrix, show that $BA = I$.    I do not understand anything more than the following.   Elementary row operations. Linear dependence. Row reduced forms and their relations with the original matrix.   If the entries of the matrix are not from a mathematical structure which supports commutativity, what can we say about this problem?  P.S.: Please avoid using the transpose and/or inverse of a matrix.


I've encountered a problem with backreferences from my bibliography (biblatex, biber) to the frontmatter of my document when using "greek" as a babel option in my document. The following seems to be a minimal example. It does not matter if greek is the main language or an additonal one (see commented line).  \documentclass{book} \usepackage[     backref=true,     backend=biber, ]{biblatex}  %\usepackage[greek, english]{babel} \usepackage[greek]{babel} \usepackage[utf8]{inputenc}  \addbibresource{\jobname.bib} \usepackage{filecontents}  \begin{filecontents}{\jobname.bib} @book{key, author = {Author, A.}, year = {2001}, title = {Title}, publisher = {Publisher}, } \end{filecontents}  \begin{document}  \frontmatter  Here I reference the book \cite{key}.  \mainmatter  \printbibliography  \end{document}   The console output starts  This is pdfTeX, Version 3.14159265-2.6-1.40.17 (MiKTeX 2.9.6100 64-bit)   and the error is  (backrefstartmatter.aux  ! LaTeX Error: Missing \begin{document}.  See the LaTeX manual or LaTeX Companion for explanation. Type  H <return>  for immediate help.  ...                                                l.13 ...}{{\fontencoding  {OT1}\selectfont  i}}{1}   The corresponding section of the .aux file is   \abx@aux@backref{1}{key}{0}{{\fontencoding  {OT1}\selectfont  i}}{1}   Any ideas? Thanks in advance.

Until recently, one could redefine \textlatin to expand to its argument in order to allow index entries using Roman numerals and babel when a non-ASCII encoding is loaded together with ASCII encodings.  The recent changes to babel now make that obsolete. If any non-ASCII encoding is present, an encoding selection is made, along with a font switch. This is done via \AtBeginDocument and the process related to \ensureascii.  Consider this MWE:  %!TEX program=pdflatex  \documentclass{memoir}  \usepackage[utf8]{inputenc} \usepackage[LGR,T1]{fontenc} \usepackage[greek,english]{babel} \usepackage{makeidx} \makeindex  \begin{document} \frontmatter \meaning\thepage  \index{\string\thepage}  \mainmatter \meaning\thepage \index{\string\thepage}  \backmatter \printindex \end{document}   The .idx file will have:  \indexentry{\string\thepage}{{\fontencoding  {T1}\selectfont  i}} \indexentry{\string\thepage}{1}   That will not play well with makeindex for similar reasons as the former use of \textlatin. One will lose all one's index entries in the front matter.  Is there any elegant workaround that anyone has discovered? Or perhaps stick with an old version of babel?  I hesitate to use sed to stroke the .idx file in conjunction with latexmk, which otherwise does a marvelous job at creating the document on which I am working.  Although I understand why this design decision is quite helpful in many places, it does complicate indexing.


I just started learning LaTeX, and I'm having trouble to write a symbol, LaTeX.

I want to get that fancy LaTeX symbol to put in one of my documents but I cannot find it anywhere.  All searching for things like latex symbol have not resulted in the symbol but other symbols.


I want to do something similiar like this picture in Gimp (or Photoshop if required). Any ideas on how to proceed? Anything useful will be appreciated.

How would I go about making a texture similar to the one used throughout :     Is it some kind of noise pattern?


Hey I have a list where I would want to get all the different permutations of it i.e [A,B,C].  I want all different combinations of it. like so [A,C,B], [B,A,C], [B,A,C], [C,A,B] and [C,B,A] i tried using itertools.combinations and I get all combinations just not the ones with all letters in use.  matriks = ["A","B","C"]     combs=[]     for i in xrange(1, len(matriks)+1):     els = [list(x) for x in itertools.combinations(matriks, i)]     combs.append(els) print(combs)   this gives the following output  [[['A'], ['B'], ['C']], [['A', 'B'], ['A', 'C'], ['B', 'C']], [['A', 'B', 'C']]]

How do you generate all the permutations of a list in Python, independently of the type of elements in that list?  For example:  permutations([]) []  permutations([1]) [1]  permutations([1, 2]) [1, 2] [2, 1]  permutations([1, 2, 3]) [1, 2, 3] [1, 3, 2] [2, 1, 3] [2, 3, 1] [3, 1, 2] [3, 2, 1]


I've seen it claimed in physics classes that there is an isomorphism of Lie algebras  $$\mathfrak{so}\left(1,3\right)\cong \mathfrak{su}\left(2\right)\oplus\mathfrak{su}\left(2\right)$$ However, the argument used relied on taking complex linear combinations of a basis for $\mathfrak{so}\left(1,3\right)$ so that the resulting basis contained two copies of $\mathfrak{su}\left(2\right)$.   Namely, there is a basis for $\mathfrak{so}\left(1,3\right)$ given by $\left\{J_1,J_2,J_3,K_1,K_2,K_3\right\}$ with  $$\left[J_i,J_j\right]=\sum _{k=1}^3\varepsilon _{ijk}J_k$$ $$\left[K_i,K_j\right]=\sum _{k=1}^3\varepsilon _{ijk}J_k$$ $$\left[J_i,K_j\right]=\sum _{k=1}^3\varepsilon _{ijk}K_k$$ The new elements $J_i^{\pm}=J_i\pm iK_i$ then have the commutation relations of two copies of $\mathfrak{su}\left(2\right)$.   The problem I have with this derivation is that $\mathfrak{so}\left(1,3\right)$ and $\mathfrak{su}\left(2\right)$ are real Lie algebras. So, taking complex linear combinations doesn't really make sense.   Is the stated result true?

I'm desperatly confused by notations and formulations so if someone could clarify the following things a little Í would be deeply grateful. The Lie algebra $\mathfrak{so}(1,3)_+^{\uparrow}$ of the proper orthochronous Lorentz group $SO(1,3)_+^{\uparrow}$ is given by \begin{equation} [J_i,J_j]=i \epsilon_{ijk} J_k \end{equation} \begin{equation} [J_i,K_j]=i \epsilon_{ijk} K_k \end{equation} \begin{equation} [K_i,K_j]=- i \epsilon_{ijk} J_k \end{equation} We can now define new generators with the old ones $N^{\pm}_i= \frac{1}{2}(J_i \pm i K_i)$ which satisfy \begin{equation} [N^{+}_i,N^{+}_j] = i \epsilon_{ijk} N^{+}_k ,\end{equation} \begin{equation} [N^{-}_i,N^{-}_j] = i \epsilon_{ijk} N^{-}_k ,\end{equation} \begin{equation} [N^{+}_i,N^{-}_j] = 0. \end{equation} where we can see that $N^{+}_i$ and $N^{-}_i$ make up a copy of the Lie algebra $\mathfrak{su}(2)$ each. My problem is to get what is going one here mathematically precise. Are the following statements correct and if not why:  When we build the new operators from the old generators we complexified $\mathfrak{so}(1,3)_+^{\uparrow}$ \begin{equation}(\mathfrak{so}(1,3)_+^{\uparrow})_\mathbb{C} = \mathfrak{so}(1,3)_+^{\uparrow}\otimes \mathbb{C} \end{equation} We saw that $\mathfrak{so}(1,3)_+^{\uparrow})_\mathbb{C}$ is isomorph to two copies of the complexified Lie algebra of $\mathfrak{su(2)}$: $(\mathfrak{so}(1,3)_+^{\uparrow})_\mathbb{C} \simeq \mathfrak{su(2)}_{\mathbb{C}} \oplus \mathfrak{su(2)}_{\mathbb{C}} $. Where exactly did we need that $\mathfrak{su(2)}$ is complexified here? The Lie algebras defined by $N^{\pm}_i$ are exactly those of $\mathfrak{su(2)}$ and we never use complex linear combination of $N^{\pm}_i$ or am I wrong here? $\mathfrak{su(2)}_{\mathbb{C}}$ is isomorph to $(\mathfrak{sl}(2,\mathbb{C}))_\mathbb{C}$: \begin{equation}\mathfrak{su(2)}_{\mathbb{C}} \simeq (\mathfrak{sl}(2,\mathbb{C}))_\mathbb{C} \end{equation} Here $(\mathfrak{sl}(2, \mathbb{C}))_\mathbb{C}$ denotes the complexified Lie algebra of $SL(2,\mathbb{C})$ Is $(\mathfrak{so}(1,3)_+^{\uparrow})_\mathbb{C} \simeq (\mathfrak{sl}(2, \mathbb{C}))_\mathbb{R}$ correct?  Here $(\mathfrak{sl}(2, \mathbb{C}))_\mathbb{R}$ denotes the real Lie algebra of $SL(2,\mathbb{C})$ Is $(\mathfrak{so}(1,3)_+^{\uparrow})_\mathbb{C} \simeq (\mathfrak{sl}(2, \mathbb{C}))_\mathbb{C} \oplus (\mathfrak{sl}(2, \mathbb{C}))_\mathbb{C}$ correct?  I looked this topic up in different books and each seemed to state something different. One book even used three differrent versions of $\mathfrak{sl}(2,\mathbb{C}) $ namely: $\mathfrak{sl}(2,\mathbb{C}) $, $(\mathfrak{sl}(2,\mathbb{C}))_\mathbb{C}$ and $(\mathfrak{sl}(2,\mathbb{C}))_\mathbb{R}$.  states simply that $\mathfrak{sl}(2,\mathbb{C}) $ is the complexification of $\mathfrak{su(2)}$ without making any reference to $SL(2,\mathbb{C})$ which does not help me either. Any help would be great.


Solving $\begin{cases} 4u_{tt}-3u_{xt}-u_{xx}=0\tag1\\u(x,0)=x^2\quad\text{and}\quad  u_t(x,0)=e^x\end{cases}$ in $\mathbf R\times\mathbf R_{>0}$   First I factorized and get for the first line;  $(\partial_x-4\partial_t)(\partial_x+\partial_t)u=0$ and set $v:=(\partial_x+\partial_t)u$  then $v_x-4v_t=0$ is transport equation with solution $f\left(x+\frac{1}{4}t\right)$  hence  $(1)$ is reduced to $u_x+u_t=f\left(x+\frac{1}{4}t\right)$. This is nonhomogeneous transport equation with solution  $$u(x,t)=\displaystyle\int_0^t f\left(x+\frac{1}{4}t+2(s-t)\right)ds+g(x-t)$$  considering initial conditions I get $g(x)=x^2,\ $ $\ f(x)=e^x-2x$  then wolframalpha yields,   but if I apply $(1)$ to the result it is not true, where is the mistake ?

Solve $$u_{xx}-3u_{xt}-4u_{tt}=0$$ where $u(x,0)=x^2$ and $u_t(x,0)=e^x$.  My workings so far: I have factored the differential equation in the following way: $$(\delta_x-4\delta_t)(\delta_x+\delta_t)=0$$ where $\delta_x=\frac{\delta}{\delta x}$ etc. Now if we let $v$ be the solution to $(\delta_x+\delta_t)u$ then we have the following two equations: \begin{eqnarray*} (\delta_x+\delta_t)u=u_x+u_t=v\\ (\delta_x-4\delta_t)v=v_x-4v_t=0 \end{eqnarray*} Now for $v$ we simply find $$v=h(t+4x)$$ where $h$ is an arbitrary function of one variable. Now what remains is find $u$ such that $$u_x+u_t=h(t+4x)$$ I am stuck here, I thought about making a change of variables $\zeta=x+t$ and $\eta=x-t$ and thus using the product rule to show that $u_x=u_{\zeta}+u_{\eta}$ and $u_t=u_{\zeta}-u_{\eta}$ and thus $u_x+u_t=2u_{\zeta}$ and we need to solve $$u_{\zeta}=h(t+4x)$$ (I left out the factor 2 because $h$ is an arbitrary function). Do I simply integrate now and conclude $$u=f(\zeta)h(t+4x)+g(\eta)=f(x+t)h(t+4x)+g(x-t)$$ This seems wrong to me...  Some help would be greatly appreciated!


The solution from the  is to initialize the pointer after the class definition but I have found no success doing so. Trying to insert A B::AArray; or A B::AArray = new A[10]; gives me multiple errors including "conflicting declaration" and "cannot be initialized by a non-constant expression". I can't seem to find a way to define B::AArray anywhere in the code.  class A{ public:     int Avar;     A(int Avar = 0){this->Avar = Avar;} };  class B{ private:     static A *AArray; public:     static void setAArray(); };  int main(){     return 0; }  void B::setAArray(){     A *data;     data = new A[10];     AArray = data; // <- delete this line and the program complies }   This piece of code says I have an undefined reference to 'B::AArray' and won't compile. How do I resolve this if I want a static pointer to an array of class A objects in class B?  Note: my class does not use multiple files currently and everything is under one .cc file

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


Please let me know if there's a query for this case: I want to delete multiple rows based on spesific column  id    | date       |   user    | item  |      material      | Text | Description | ------+------------+-----------+-------+--------------------+------+-------------+ 12345 | 31.03.2015 | Starbucks | 00010 | 000000001011000106 | abcd |  something  |  null  | 31.03.2015 | Starbucks | 00010 | 000000001011000106 | abcd |  something  |  54321 | 31.03.2015 |   Burger  | 00010 | 000000001011000106 | abcd |  something  | 11111 | 31.03.2015 |   Burger  | 00010 | 000000001011000106 | abcd |  something  |   Let say I want to delete multiple rows that contains user "Starbucks" more than 1, I want to delete the one that has id null. But if there's no id that contains null, like "Burger", I just want to delete one, and pick 1 whatever it is. So, it should be like this :  id    | date       |   user    | item  |      material      | Text | Description | ------+------------+-----------+-------+--------------------+------+-------------+ 12345 | 31.03.2015 | Starbucks | 00010 | 000000001011000106 | abcd |  something  |  54321 | 31.03.2015 |   Burger  | 00010 | 000000001011000106 | abcd |  something  |   Can I?

What is the best way to remove duplicate rows from a fairly large SQL Server table (i.e. 300,000+ rows)?  The rows, of course, will not be perfect duplicates because of the existence of the RowID identity field.  MyTable  RowID int not null identity(1,1) primary key, Col1 varchar(20) not null, Col2 varchar(2048) not null, Col3 tinyint not null


I’m trying to create a material for a button on a music control panel. It looks like a plastic glossy button with some colourful light coming from behind.   I’m using EEVEE engine, so I tried bumping the transmission to 100% and also checking the refraction in the render settings, but it’s not the best looking button, it seems not transparent.    Q: How to create a realistic looking shader for that plastic knob using eevee?

I need to know how to make the buttons in my blender project look the same as in this photo. Mine all look pale, even with the emission material. Is there anyway I can get my buttons like this?


Can anybody refer me to a font file or typeface that contains the proper US dollar sign?  A problem with most typefaces is that they contain a generic dollar sign, containing a single vertical bar. A US dollar sign contains two vertical bars. The commonly used alternatives are $us9.99 or us$8.88.  Explanation: The original US dollar sign was a monogram of US. It consisted of a sanserif capital S, with a narrow sanserif capital U centered on top of it. Later, the bottom of the U was removed.

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


I am selecting a single column of foreign keys from multiple tables through either UNION or UNION ALL.  It is generally recommended to use UNION ALL instead of UNION for performance issues when duplicates do not matter. However, in my calling PHP script it would be more efficient to loop through and manipulate the data without duplicates.   So, I can use either of the following options:  Option 1:  Use UNION in the database to eliminate duplicates  Option 2:  use UNION ALL in the database and eliminate the data in my PHP script using array_unique() or other similar functions.   My assumption is that Option 1 would be the preferred and more efficient method in the majority of cases, however I have nothing to back up that assumption, and not sure the best way to test it especially since it would likely depend a lot on what the data was.  Is my assumption correct in most cases? If so, why? If not, why not?

What is the difference between UNION and UNION ALL?


I am using HuaWeiNova device, and I tried to access it with aft-mtp-cli. $ aft-mtp-cli $ ls DCIM/  I got folders listed here: |-photos |-Camera ....  When I tried to list or download my photos in the Camera/ folder, I got nothing. Only the empty folders are listed and the folders that contains files are not shown at all. I am quite sure my photos are stored in the Camera folder in my cell phone. How come I could not access my photos with my computer ?

I have LG L5 (e610 model) device with Cyanogenmod 10. When I connect the phone to a computer with Linux (I have mtpfs installed), I can see both internal storage and the SD card.  However when I navigate inside them, I can't see some of the files.  For example, if I open file manager app on the phone, I can see several files in the Internal storage/Notifications directory, however the directory on the computer only shows one of those files.  If I switch USB connection type to PTP (camera) - as OS X doesn't support MTP natively - Image Capture sees the phone as a camera, however it can only see about a third of all the images present on the phone.  I don't have a Windows machine to try, but I suspect the results would be similar.  I tried upgrading Cyanogenmod to the latest nightly, clearing and reinstalling it - same results.  Any idea as to what is going on?  How can I make all files appear on the host computer?


In order to do that I want to find two subsequences $a_n$ and $b_n$ of $\sin (n) $ such that $\lim_{n \to +\infty} a_n $ and $\lim_{n \to +\infty} b_n$ are not the same number.  Hints?

I am looking for nice ways of proving the divergence of the sequence $\left\{x_n\right\}_{n=1}^{\infty}$ defined by $$x_n=\sin{(n)}.$$ One (not so nice) way is to construct two subsequences: one where the indexes are picked such that they lie in the intervals  $$I_k=\left(\dfrac{\pi}{6}+2\pi(k-1),\dfrac{5\pi}{6}+2\pi(k-1)\right)$$ and one where they lie in $$J_k=\left(\dfrac{7\pi}{6}+2\pi(k-1),\dfrac{11\pi}{6}+2\pi(k-1)\right).$$ If ${x_n}$ converges, then all its subsequences must converge to the same limit, but here the first subsequence has all its values in the interval $\left[ \frac{1}{2}, 1\right]$ while the second has its values in $\left[-1,-\frac{1}{2}\right]$. Contradiction.  Filling the details of this proof is rather tedious and not very elegant. Anyone has a better idea?


Was asked this after a student wanted to talk about how Mrs Birling lost sympathy for the working class after seeing them so many times. Please just one word to describe this situation. Thanks

Is there a term for this? I had my SIL's birthday present on my desk for weeks, and then the day I went to visit her, I forgot to bring it with me because it had sort of become part of the furniture and I didn't notice it there. Or when you walk into a room and notice the smell, but then you get used to it after a while so you don't notice it anymore. Or you walk past a shop so often that you don't notice it, and when you want to buy something that the shop sells, you forget about the shop's existence because you don't notice it anymore.


I am using dual boot of Windows 10 and Ubuntu 18.04.  Wifi networks are not showing in Ubuntu but it is working fine in Windows 10. It is unable to detect wifi networks on Ubuntu. When I make the hotspot then it shows only that network but it is unable to show all the available networks which can be easily shown on Windows 10. After running  script, I got the report:-  When I give command dmesg, I got error as "rtlwifi: AP off, try to reconnect now" Is this a problem ? When I give command ispci then I got  result Please help. Please find the attachments regarding the problem:

I have a HP 14-AN001NA laptop. It came with Windows 10 installed on which the Wi-Fi worked fine anywhere in the house.   However I removed Windows 10 and installed Ubuntu 16.04 instead and since I have had terrible Wi-Fi anywhere aside from about three foot away from the router. I don't know if it's relevant but my Wi-Fi is not called wlan0 but wlo1 for some reason (I didn't change it).  When running lspci -knn | grep Net -A3     I get the following output:  05:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723] DeviceName:   Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:81c1] Kernel driver in use: rtl8723be Kernel modules: wl, rtl8723be


Perhaps I haven't understood the concept of the "Scaling Workflow" and hence my confusion ...  I checked out most of the Q&A for designing large format images on Photoshop (like for huge billboards), and the most popular suggestions were to "scale" the image down and design at high resolution.  Examples -     For instance, if a billboard is to be 20' wide, the vendor may ask you   to send a file 20 inches wide. If the billboard will be printed at   40ppi, then your 20" wide file would need to be set to 480ppi to allow   for the scaling (12X40).   Source:      30 dpi for final output is more than enough for a billboard of that   size. It's not unusual for final output to be 12-15 dpi in this   context. The usual professional billboard workflow in Photoshop is to   build the image at a small scale with high ppi (e.g., 4x6cm @ 300   ppi),   Source:   How does this help?   For example, let's assume a billboard's print spec is 35 meters (W) x 15 meters (H) at a resolution of 50 DPI / PPI in CMYK. And the billboard designing will be done with a raster image using Photoshop.  So how does it help if you design it at 350 cm x 150 cm @ 500 ppi (scaled to 1/10, for example) or at its actual size of 3500 cm x 1500 cm @ 50 ppi?   Calculation -  A 350 cm x 150 cm @ 500 PPI will have ~ 68,898 x 29,530 pixels (350 cm = 137.795 inch x 500 PPI = 68897.5 and 150 cm = 59.06 inch x 500 PPI = 29,530).  A 3500 cm x 1500 cm @ 50 PPI will also have 68,898 x 29,528 pixels (3500 cm ~ 1377.953 inch x 50 PPI = 68897.65 and 1500 cm ~ 590.56 inch x 50 PPI = 29,528).  In both cases, the file size in Photoshop is going to be approximately the same (around 4+ GB!), since the amount of pixels in both the Photoshop file will be the same! When the document size is the same for both cases, how can Photoshop use less resource for the "scaled" down size? How does it become easier to design using a "scaled" down version?    To be clear, I understand the theory of why a lower resolution works with large images for bill boards.    My question pertains to the "scaling" designing workflow that was suggested for editing large raster images (mainly in photoshop). I fail to see what benefit this approach offers, and hence my query ...

(This question is meant to be a resource to direct others to given that this is a common question.)  Given the task of creating an image that will be printed at a certain size, what pixel dimensions and resolution should I be setting my file at?


My college just blocked Ubuntu repositories. So is there any way to install texlive package from something like zip?  I need to run this command,   sudo apt-get install texlive texlive-pdf texlive-latex-extra texlive-generic-extra texlive-generic-recommended   So can anyone provide an alternate way to do the same.

I have a friend who has got a computer that is not connected to the Internet. Is there any way to install software offline easily?


I have a background as a developer, but have been working on test automation here in the UK for the last years. I work a lot with Java, Webdriver and Jenkins/continuous deivery - but I am very interested in "switching" career to more devops since I already love and work with automation.   How do you make such a transition and where do you begin?

I've been testing Ubuntu daily builds for QA since last month.  I wasn't too confident in learning development yet, because I didn't feel familiar with encountering a bunch of code. But I want to write code and develop software one day.   So far, I see QA work as active testing, communication via mailing lists, and reporting bugs.   In what ways is quality assurance testing a first step into development?  Thanks for your time.


Is it possible to hide the "Show Desktop" icon in the application switcher (when you press Alt+Tab)?  It's very annoying when you have a workflow, press Alt+Tab one time too much and every window is minimised.

Is it possible to remove "Show Desktop" from the Alt+Tab application switcher?


I stupidly ran this command in Ubuntu 18.04:  sudo chown -R $USER:$USER /usr   Now I want to undo this but when I run:  chown -R root:root /usr   I get this error:  operation not permitted   And I can't run a sudo command and gives me this error:  /usr/bin/sudo must be owned by uid 0 and setuid bit set   How can I fix this?

I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back?


I tried:  $ locate 'tar' | head -2 /bin/tar /bin/unicode_start   How I can get rid of this 'unicode_start'?

I made the mistake of copying the same files to different partitions with good intentions of pruning (deleting) them from the source or target(s) later. Now when I try to locate them I get too many results from locate command:  rick@alien:~$ locate "display-auto-brightness" /etc/cron.d/display-auto-brightness /home/rick/Pictures/display-auto-brightness conky.png /home/rick/Pictures/display-auto-brightness systray.png /home/rick/Pictures/display-auto-brightness-config 1.png /home/rick/Pictures/ps display-auto-brightness.png /lib/systemd/system-sleep/display-auto-brightness /mnt/e/etc/cron.d/display-auto-brightness /mnt/e/lib/systemd/system-sleep/display-auto-brightness /mnt/e/usr/local/bin/display-auto-brightness /usr/local/bin/display-auto-brightness   The locate command is automatically placing the * wild card after the search string and returning extra undesired results. The .png files should not be returned.  Why is locate returning too many results?


Is it possible to show (pop-up) a message box with an input field in it, possibly a text box? Is somewhere in the language or the framework?

What is the C# version of VB.net's InputBox?


I have the following $n\times n$ matrix:  $$A=\begin{bmatrix} a & b & \ldots & b\\ b & a & \ldots & b\\ \vdots & \vdots & \ddots & \vdots\\ b & b & \ldots & a\end{bmatrix}$$  where $0 < b < a$.  I am interested in the expression for the determinant $\det[A]$ in terms of $a$, $b$ and $n$.  This seems like a trivial problem, as the matrix $A$ has such a nice structure, but my linear algebra skills are pretty rusty and I can't figure it out.  Any help would be appreciated.


I defined a new environment eq to simplify the equation,  \newenvironment{eq}{\begin{equation}}{\end{equation}   It works, but it seems that there is a extra space at the end of the environment, which can be tested as in the following command:  \documentclass{amsart} \begin{document} \begin{eq} a+b=c \end{eq} There is a extra space at the end of ``eq'' environment.  \begin{eq} a+b=c \end{eq}% NO extra space exists at the end of ``eq'' environment. \end{document}   My question is how to delete the extra space automatically?

If I create a custom environment based on the equation environment, I get a spacing issue: the next line of text after my environment closes doesn't start on the left margin.  Example code:  \documentclass{article} \begin{document} \newenvironment{myenv}{\begin{equation}}{\end{equation}} \noindent $| \leftarrow$ this is the left margin. \begin{myenv} e ^{i \pi} + 1 = 0 \end{myenv} $| \leftarrow$ this isn't the left margin. \end{document}   Output:    Removing the newline after \end{myenv} solves the spacing problem, but the resulting code is not readable.  Of course, in this example I could just use the equation environment itself. My real issue involves a more complex custom environment that suffers from the same problem, and which also includes an equation environment within it.


While updating metadata of field type TaxonomyFieldValueCollection I am getting following error.     "{"error":{"code":"-1, Microsoft.SharePoint.Client.ClientServiceException","message":{"lang":"en-US","value":"Cannot deserialize data for type Microsoft.SharePoint.Taxonomy.TaxonomyFieldValueCollection."}}}"

I'm getting the following error when trying to update a taxonomy field value via REST api:  {   "error": {     "code": "-1, Microsoft.SharePoint.Client.ClientServiceException",     "message": {       "lang": "en-US",       "value": "Cannot deserialize data for type Microsoft.SharePoint.Taxonomy.TaxonomyFieldValueCollection."     }   } }   The request:  https://server/_api/web/GetFileByServerRelativeUrl('/Shared Documents/file.txt')/ListItemAllFields  {   "__metadata": {     "type": "SP.Data.Shared_x0020_DocumentsItem"   },   "Title": "some title",   "Project": {     "results": [       {         "Label": "Term1",         "TermGuid": "897bdf7f-08d6-44b9-a71a-ddc4cf131664",         "WssId": 5       }     ]   } }


Hello can anyone please help me with the following, I try to find a delphi routine which allows me to find which other program is holding a comport. (A comport I want to open is occupied by another application which application does that).  I am aware of the tool to find it but I would like to do that programmatically in my application, please can someone give me a hint? Thanks

The company I work for makes hardware that communicates to the computer though a serial port. Third party companies write software that communicates with our hardware.   There are times when I need to diagnose our hardware. However, a third party software app connects to the serial port when Windows starts up, blocking any other connection. I don't know the name of this application/service and it's not always the same one.  Is there any way to either:   Find the name/pid of the app/service that is currently using a given serial port or Steal the serial port connection from another app.   vb.net preferably, but I'll take a language agnostic answer as well.


The following proof sketch is from the preface of Tristan Needham's Visual Complex Analysis:    Why is the left side of the black triangle labeled $L \, d\theta$?  I can see that the length of this side is $L \tan{d\theta}$, so it seems that Needham is approximating $\tan{d\theta}$ with $d\theta$ as $d\theta$ approaches $0$. Why is this justified? It makes sense to me in light of the fact that the derivative of $\tan{\theta}$ at $\theta = 0$ is $1$, but this doesn't seem like the intended justification, given what he's trying to prove. Is there another, more obvious (and perhaps geometric), justification?

I was reading Needham's Visual Complex Analysis, and could not figure out how we get length $Ld\theta$ here:


As always, there are very similar questions on here but none quite applies to my context.  I have text coming from a textarea on a different page. I need to scan it for special characters, and assign it to a new string before inserting it into my SQL database. This was what I thought would work, but it seems to to absolutely nothing (the code still works, but the special characters remain).  $info = htmlspecialchars($_POST['info']);   The text could contain just about anything in the way of special characters (in particular, lots of üèéöàä etc.).

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


Is it safe to install ubuntu alongside windows 7?  I have a laptop with 500 GB hard disk and 2 GB RAM and it is pre-installed with windows 7.My professor asks me to install ubuntu 12.04 alongside Windows 7.  However I am not sure whether it is safe to make a dual boot system? Will it affect my hard disk ?Is there any chance of a hard disk crash?  Please help.

Is it really safe to choose the "Install Ubuntu alongside Windows" option from the Ubuntu installation program?  I never used that option, instead I used other tools such as partition magic or windows 7's disk tool to resize my partitions.  Since I'm going to install Ubuntu across a lot windows (XP, Vista and 7) machines. It would not be nice to damage those Windows partitions.  What is your experience? Can I use this feature without concerns?


I have a problem like this. I have two lists, A and B, where A=[[1,2],[3,4],[5,6]] and B=[["a","b"],["c","d"]], I would like to got a new list from these two like   C = [      [[1,2],["a","b"]],      [[3,4],["a","b"]],      [[1,2],["c","d"]],      [[3,4],["c","d"]]     ]   I had try the following code:  A = [[1,2],[3,4]] B=[["a","b"],["c","d"]] for each in A:     for evey in B:         print each.append(evey)   However, the output is None.   Any helpful information are appreciated. Thank you.  By the way, I had try to replace the "append" with simple "+". The output is a list which elements are not list.

How can I get the Cartesian product (every possible combination of values) from a group of lists?  Input:   somelists = [    [1, 2, 3],    ['a', 'b'],    [4, 5] ]   Desired output:  [(1, 'a', 4), (1, 'a', 5), (1, 'b', 4), (1, 'b', 5), (2, 'a', 4), (2, 'a', 5) ...]


Why does the integrand of a line integral consist of a dot product between the vector filed $\vec F$ and the unit tangent vector $\hat T$( or normal $\hat n$ )? Does this follow from physical examples( Work done, for an example ) or is there a particular reason behind considering the dot product?

I can understand how the line integral of a scalar function has pure-mathematical significance, representing an area beneath a curve. But is there a pure significance to the line integral of a vector field? The only understanding I have of this is the physical example of work done on a moving particle. Thanks for any insight.


My data is stored in firebird database. The actual data is  "E…" but when queried in PHP it shows as  "E�" How to get correct data?


I've tried to repair boot, when I try to repair, in the Recovery menu enter Enable networking, the following error occurs:  /etc/resolv.conf : No such file   I'm using dual boot and with the windows everything is ok.  I've also tried to change the grub options and added acpi=off without success.  I'm not sure what this is due for and how to fix these issues.  Now when I boot, I get only the screen with these errors:  Hardware Error: CPU 0. Machine Check : 0 Bank 5 Hardware Error: PROCESSOR 0:40651 TIME 1522499587 SOCKET 0 APIC 0 microcode 23 /dev/sda7: clean, 1771662/15261696 files, 27942468/61035264 blocks   Edited: I now got this error when trying to reboot with kubuntu:  [Firmware Bug]: TSC_DEADLINE disabled due to Errata   How should I fix that? Yesterday everything worked just fine.

I saw several bugs and error messages when I was looking by chance into the tool called "logs".  Being a newbie in Ubuntu I have no idea how to deal with these bugs, where to report them or how to fix them.  Any help to guide me here?  The bug I have (which is listed under important) reads:  [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)


This error comes up everytime   failed to load image grub error efi failed to start image   Then I get redirected to boot menu and every option has the same effect i.e the same error. I even tried inserting a recovery drive through usb and it resulted in the same error.

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


From what I am understanding, there is entanglement in a system if there is a correlation between elements of that system. For an example that I found, If you have only two cards and know that one is red and one is black, if they are both face down and you choose one, by knowing the color of the card just chosen, you know the color of the other card. Hence these cards are 'entangled' (please correct me if I am wrong).  Now this 'correlation/entanglement' seems to be relevent only in respect to some 'reference' knowledge, that is, it is only because we know there is a correlation between cards that we can judge that the other card has to be a particular color. So this comes down, at least in part, to knowledge about the system.  So If I have a logical system, say B = Black and R = Red where upon measurement I have B XOR R where XOR is Exclusive OR, then could I say that B and R are logically entangled over XOR? I say XOR and not OR as we can not not pick (measure) both B and R simultaneously  Furthermore, if I have an equal chance of picking either B or R before measurement would it be correct to say that B and R are in a superposition? That is, the valuation of B and the valuation of R (measuring B to be true [picked] or R to be true [picked]) are in a superposition?

Consider that we have two balls, one white and one black, and two distant observers A and B with closed eyes. We give the first ball to the observer A and the second ball to the observer B. The observers don't know the exact color (state) of their balls, they know only the probability of having one or another color, until they look at them (measure). If the observer A looks at his ball he will see its color, which is white, so he immediately knows the color of the second ball. Lets call this “classical entanglement”.  My question is: What is the difference between this “classical entanglement” and the quantum entanglement, for example, of two entangled electrons with opposite spins states? Can this analogy be used to explain the quantum entanglement?


I'm a newbie to Macports and I really wonder how I can change the default mirror to . What's more, when I use Macports to install softwares from source, it always downloads from  which is not available, and I want to use  instead. Can anyone help me? Thanks a lot.

How to use a different mirror rather than the mirrors in the ?  Well, I mean not only download port.tar from other mirror, like the question , but also download packages from a different mirror.  I have noticed that when downloading packages, the port just download packages from . But I don't know how to change the mirror it get packages from.  Many thanks!  I will appreciate every answer or comment.


I have ubuntu 13.10 and I am trying to use a disk that contains a book, How to program Java, 7th edition. It is the Linux version CD and I can't figure out what program to use so I can look at the files on it.   All of the files are in .class format. I have used the windows version on another pc and it seems to work fine with jgrasp, is there something else I should be using to edit and create java programs with the .class extension?

I have been developing in the windows space with Visual Studio for a while now with work, but I have also been using Ubuntu for a while and am keen to get into some software development for linux.  I should also note. I am not looking for .NET and I am aware of mono. I am also familiar with c++ development and some python, so the language isn't so much relevant as the "all in one" aspect.  I was interested to know if there is a useful all in one code/debug/design(gui) IDE similar to something like Visual Studio but for linux?


I'm just wondering if there's a name for the distribution described by the following p.m.f.:  $$p(n) = n(1-s)^{n-1}s^2$$  where $n$ is an integer from $1$ to $\infty$ and $0\lt s\lt1$.

I was trying to fit my data into various models and figured out that the fitdistr function from library MASS of R gives me Negative Binomial as the best-fit. Now from the  page, the definition is given as:     NegBin(r,p) distribution describes the probability of k failures and r   successes in k+r Bernoulli(p) trials   with success on the last trial.   Using R to perform model fitting gives me two parameters mean and dispersion parameter. I am not understanding how to interpret these because I cannot see these parameters on the wiki page. All I can see is the following formula:    where k is the number of observations and r=0...n. Now how do I relate these with the parameters given by R? The help file does not provide much information either.   Also, just to say a few words about my experiment: In a social experiment that I was conducting, I was trying to count the number of people each user contacted in a period of 10 days. The population size was 100 for the experiment.   Now, if the model fits the Negative Binomial, I can blindly say that it follows that distribution but I really want to understand the intuitive meaning behind this. What does it mean to say that the number of people contacted by my test subjects follows a negative binomial distribution? Can someone please help clarify this?


I am using Precision X by evga and using the gtx750ti I would like to know how high I can push my graphics card without damage.

I am running a AMD Radeon HD 3650 Graphics Card. My Graphics Card Software (Catalyst) came with overclocking software to overclock my GPU. I have a few questions though:  How bad for my GPU is overclocking?   What does the following mean?  High Performs GPU Clock Setting:  300----------------750mhz  High Performance Memory Clock Setting:  400----------------450mhz  What do those two clocks represent and do?   I have looked yet cannot find a max temp for my GPU, what is the max temp that is acceptable?   When running Photoshop (especially 3D) am I going to notice speed improvements by overclocking?


Some sites have , and some don't. Which ones currently do and what is the criteria for activating this feature?

I recently received this rather amusing message while reviewing a user's first post:  Congratulations! This was only a test, designed to make sure you were paying attention. This post has already been removed, but thanks for taking time to leave feedback for the author.   What is the purpose of this test? How does the audit work? What happens if I fail? Why was the system expecting me to negatively review a good post, or positively review a bad post? A review is obviously an audit. Should I report it? Do review audits count toward the Reviewer badge? Do robo-reviewers dream of electric sheep?


I propose a special checkbox: "I'm a researcher/programmer/scientist/engineer/professional doing some work towards COVID response". Available on any site in the SE network.  This could be a problem with D3 library making some COVID visualisation (on Stack Overflow), or a math problem related to epidemic modelling (on Mathematics Stack Exchange), or a medical problem directly (on Medical Sciences Beta Stack Exchange), etc.  On every site in the network, there will be a visible tab or menu bar link called "COVID" (for example, next to the Active / Bountied toggle), where people can help specifically those who are stuck solving an urgent problem related to COVID.

I often find myself in a spot of trouble, and when I have minutes left to fix it, I sometimes turn to SO/SF to start the "community help process". I suppose a tag like "urgent" or "immediate-attention" could enable contributors with spare time easily find the most desperate situations, giving more attention to those issues and solving them quicker. Or could this be a special tab on the home page?


I'd like to remove hold of  while keeping their content in tact just in case they help anyone down the road. How can I go about doing this?  I see [deleted] users questions/answers frequently on StackOverflow, but I do not want to delete my account - just relinquish ownership of all my answers.  .

The Creative Commons FAQ      Third, if the licensor does not like how the material has been modified or used, CC licenses require that the licensee remove the attribution information upon request [...]  in 4.0, this also applies to the unmodified work.   How do I remove / dissociate my name from a post, in accordance with this clause?  Also, what are the effects of having my post dissociated from my account?  Finally, how will dissociation requests be handled for posts licensed under earlier versions of the license, which do not require dissociation upon request in all cases?


Find the minimum of $\sqrt{(x+1)^2+(y-1)^2}+\sqrt{(x+2)^2+(y+2)^2}+\sqrt{(x-1)^2+(y+1)^2}$ For real $x,y$. It is the distance of a point in a triangle from its vertexes which gives the minimum when $(x,y)$ is on the Fermat's point.  But now I am stuck in finding the location of Fermat's point.  $(1) \quad 4$ $(2) \quad 5$ $(3) \quad \sqrt{3}+2\sqrt{5}$ $(4) \quad 4\sqrt{2}$


I want to change voltage given by a little power supply that I have at home stuckd in my desk, to use it as power supply for a little DC motor.  This DC motor need an input of 3.6 volts and give me around 5.4 Watts (1500mAh).  So that power supply gives me an output of 7.62 Volts (measured with voltimeter) and 1500 mAh.  Using Ohms law "R=(V°-V¹)/I", where my itinial voltage is 7.62 and my desired voltage is 3.6, and my current required is the same 1500mAh, so my result is:   R = (7.62 Volts - 3.6 Volts) / 1.5 A = 2.62 Ohms   Then I picked a resistor of 2.6 Ω with 4 bands and 1% tolerance (red, blue, yellow, brown) and used it.  Well, I didn't test on my little motor because I don't want to waste it so I just tried to measure it using my voltimeter without link this to any led o motor and i didn't change voltage at the end. Also I was afraid to trash my motor because when I linked this resistor between positive and negative wires of my power supply it became very hot instantly.  Using this little resistor how can I test this without waste my motor and how do I know if this very resistor can handle this current?

How would one go about using a 12 V DC power source to power something which needs 4.5 V DC using resistors? Is there a way to determine how much adding a resistor would drop the voltage?


So lets say I have a cube with length of 6 and I would like to slice it in 4 pieces, leaving me with 4 cubes with length of 1.5 each. I am aware that I can do that with knife tool, but how to slice cube in exact 4 pieces?  Is that possible with Blender?  UPDATE:  Slicing with Loop Cut and Slide as will work on normal cube, but in case geometry is a bit complex, it will not work.

I am working on a game-engine and the time has come to model a simple map. I thought, since i already use blender for models, why not for the map, since creating a world-editor can be time-consuming. The problem is, my engine expects the world to be in quadratic chunks of equal size. I'd like to model the map as a big plane with structures on-top in Blender and afterwards, cut the whole scene with plane and structures in equal quads to export them individually. Is this possible?  Example:   I'd need the whole terrain-plane to get split at the red lines and the little house, so every part of the house is in the corresponding chunk when i export the chunks.  Alternatively, when i create multiple equal-sized quadratic planes, to somehow glue one edge of one plane to another edge of another plane, so i neither get holes in between, nor get overlapping faces?


If you have algebraic numbers $x$ and $y$, and you know the polynomials of least degree of which each is a solution (written as a vectors of coefficients), then how is the vector of coefficients of the polynomial of least degree of which $x y$ is a solution found; and likewise for $x+y$?

Suppose $E/F$ is a field extension and $\alpha, \beta \in E$ are algebraic over $F$. Then it is not too hard to see that when $\alpha$ is nonzero, $1/\alpha$ is also algebraic. If $a_0 + a_1\alpha + \cdots + a_n \alpha^n = 0$, then dividing by $\alpha^{n}$ gives $$a_0\frac{1}{\alpha^n} + a_1\frac{1}{\alpha^{n-1}} + \cdots + a_n = 0.$$     Is there a similar elementary way to show that $\alpha + \beta$ and $\alpha \beta$ are also algebraic (i.e. finding an explicit formula for a polynomial that has $\alpha + \beta$ or $\alpha\beta$ as its root)?    The only proof I know for this fact is the one where you show that $F(\alpha, \beta) / F$ is a finite field extension and thus an algebraic extension.


When I cast the numbers in the matrix as np.float32 the values are slightly modified:  In [1]: matrix_32 = np.asarray([    ...:    [0.7, 3],    ...:    [1.7, 2],    ...:    [0.7, 9]    ...: ], dtype=np.float32)  In [2]: matrix_32 Out[2]:  array([[ 0.69999999,  3.        ],        [ 1.70000005,  2.        ],        [ 0.69999999,  9.        ]], dtype=float32)   However, when I cast the numbers as np.float64 the values are shown as expected:  In [3]: matrix_64 = np.asarray([    ...:    [0.7, 3],    ...:    [1.7, 2],    ...:    [0.7, 9]    ...: ], dtype=np.float64)  In [4]: matrix_64 Out[4]:  array([[ 0.7,  3. ],        [ 1.7,  2. ],        [ 0.7,  9. ]])   Can somebody explain why this happens?

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


As new players, we ran our first dongeon and the session left me a bitter taste. Some part lasted a long time without being usefull, those parts were when we were searching for treasures or traps. Indeed, before entering EVERY room the group was : "we look at the door/every tile we step on/wall to determine if there is a hidden trap", and the DM to reply "OK roll for an investigation/perception". And actually there were only one trap for the full dongeon... Then when we entered a new rom, EVERY player were asking the DM : "I am searching for a hidden treasure/loots/secret door". And the DM, one player at a time : "ok roll", just in order to loot a few pieces from the dead bodies or nothing most of the time... My questions is : how to manage Traps/Loots/Hidden Treasures without rolling everytime  for everyone and avoiding (as much as possible) to miss a secret door/treasure/hidden trap ?

I think I've gotten the wrong end of the stick when it comes to what and when the DM should be calling for rolls when the party is exploring a dungeon.   Picture your typical D&D dungeon crawl. There's winding passageways, a handful of monsters on the prowl, one or two traps and a couple of secrets. My party, understandably, wants to move stealthily, keep an eye out for traps, and watch for secrets. We're playing in roll20 with dynamic lighting on, so they can only see a few squares in all directions, making travel treacherous.   As it stands I end up having them advance a few squares at a time, calling for a new perception check every time they find a new passageway, asking for stealth checks every now and again and having the rogue roll to look for traps each time they wander down a new hall.   This feels clunky, repetitive, and subject to . The more they roll, the more likely it is someone will fail badly enough to be spotted by a monster or fall prey to a trap. However, running the entire dungeon on a single set of rolls seems to be against the whole spirit of dungeon crawling; why bother to explore a dungeon at all when a single roll has determined your fate?  I'm aware of the rationale  behind  in premade maps. In an ideal world you'd design a dungeon crawl that was only rooms, and parcel out your checks per room. But what about a cave system? There's no "rooms", per se... the whole map IS long, possibly empty "hallways". Sometimes you really are trying to navigate a large area with no obvious beginning or end.   I'm sure I'm missing something here... when, and how often, should players be rolling when dungeon crawling?


I want to keep track of the instance of MyClass, so I have add a private static variable std::map<int,MyClass*> inside MyClass. The problem now is it causes unresolved external symbol, which I don't know how to debug. How can I resolve this?  Note: I'm a seasoned Java programmer and novice C++ programmer, and also I'll be using this as a JNI dll, that is why I need to keep track the instances of MyClass.

Very simply put:  I have a class that consists mostly of static public members, so I can group similar functions together that still have to be called from other classes/functions.  Anyway, I have defined two static unsigned char variables in my class public scope, when I try to modify these values in the same class' constructor, I am getting an "unresolved external symbol" error at compilation.  class test  { public:     static unsigned char X;     static unsigned char Y;      ...      test(); };  test::test()  {     X = 1;     Y = 2; }   I'm new to C++ so go easy on me. Why can't I do this?


I'm trying to find the best structure for a local business service that has a multilingual website.  Actually, the website has a simple structure: www.brand.com/fr/ www.brand.com/en/  I'm considering to replace www by taxi, which is the business activity in order to give some context to the brand name which has no keyword related to the activity. The URL could look like that taxi.brand.com/fr/ taxi.brand.com/en/  With specific pages targeted for locations it could look like that taxi.brand.com/fr/location/ taxi.brand.com/en/location/  Another alternative would be to use subdomains for locations location.brand.com/fr/  Or to use the language code as subdomain fr.mydomain.com/location/  What are your thoughts on the optimal structure from an SEO perspective?

What would you recommend as a URL structure for setting up a multilingual site when optimizing for SEO?  I'm thinking:  www.yoursite.com/en/some-category/some-article/ www.yoursite.com/sv/en-kategori/en-artikel/ (Swedish)   Or would you prefer creating a subdomain (i.e. sv.yoursite.com) or similar instead?  From what I know it seems easier integrating a /language/ directory when in combination with .htaccess.


I'm working on an app that has strings in an array like:  static char * strings[] = {   "ABC DEF",   "EF",   "GHI" };   Note, that the type doesn't have const modifier!  In my app I loop over the array and revert the strings. The expected result is:  {   "FED CBA",   "FE",   "IHG" }   However the result I get is:  {   "FED CAB",   "AB",   "IHG" }   The reason for this is because in the original array the strings are compiled to overlap: strings[1] overlaps the end of strings[0]!!!  // When I printed out the pointers it turned out that in the RAM // it stored my strings "overlapping": //  00 01 02 03 04 05 06 07 08 09 0a 0b // "A  B  C  __ D  E  F  \0 G  H  I  \0"  static char * strings[] = {   0x00, 0x05, 0x08 };   Is there any way (besides not having the const modifier which doesn't work) to tell the compiler not to overlap my strings? Is this a bug in the compiler or in my code? What workaround can I do?

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


I was reading the  of the IC 4082 but I was not able to understand what are input clamping current and output clamping current of the integrated circuit. Can someone explain these terms?

While reading a , I found the parameters Input clamp current / Output Clamp current. Where do I consider these specifications?


In scholar we can list our fields of interest. Whenever you click them, scholar shows the most cited researchers in that field like . Is there a way to sort google scholar profiles by country, in a given field?

On Google Scholar, you can do an author search based on keywords. For example, if I find an author who has "Robotics" as a keyword, and I click on that keyword, it lists all the authors with that keyword, in order of the number of citations.  What I would like to do, is see that same list, but:  1) Only for authors in my country  And:  2) By combining it with another keyword, e.g. all the authors who have "Robotics" and "Machine Learning".  Is this kind of advanced author search possible?