I have two csv files example t_test_yyyyymmdd.csv t_test_type_yyyyymmdd.csv  I want to make the command ls to search only the file t_test_yyyyymmdd.csv

I want to list all files in a directory that start with 'abc' and end with '.zip'  I'm trying to use ls.  The directory has a lot of zip files starting with abc<date> and xvz<date>. I only want to get the list of the abc<date>.zip


In the Suggested Edits Reviewer Stats, I saw that the Reviewer has no commas and lots of "and"s:  Whereas the Editor Stats do have commas and don't run on.  Small bug, but can we give the stats some commas so it's less of a mouthful?

I've noticed that the reviewer stats in the review queue contain awkward uses of :        has approved $count edit suggestions and rejected $count edit suggestions and improved $count edit suggestions    This has always irked me but I never bothered to complain about it publicly til now. The wording should be changed to       has approved $count edit suggestions, rejected $count edit suggestions and improved $count edit suggestions    Or one of the better suggestions from   The discussion about whether there should be a  in the sentence is a separate one entirely, but I think it's unnatural and unreadable to string the ands together like they are.


I have written a wrapper class to a Mqtt PubSubClient to wrap the functionality of the PubSubClient and WifiManager library.  I would like to pass a callback to mqtt client when I initialize the Mqtt client connection, but It does not work for me:  this->client->setCallback(&this->mqttCallback);  Is there any way to reference mqttCallback function in MyMqtt class?  class MyMqtt {   public:     MyMqtt(char *device_type, int version, int status_led);        void mqttCallback(char *topic, byte *payload, unsigned int length);      PubSubClient* client; }   I can successfully reference to a global function   this->client->setCallback(mqttCallbackGlobal);  ...  void mqttCallbackGlobal(char *topic, byte *payload, unsigned int length)  { }   but I cannot refer to the instance of my MyMqtt class.

I'm using an API that requires me to pass a function pointer as a callback. I'm trying to use this API from my class but I'm getting compilation errors.   Here is what I did from my constructor:  m_cRedundencyManager->Init(this->RedundencyManagerCallBack);   This doesn't compile - I get the following error:      Error  8 error C3867: 'CLoggersInfra::RedundencyManagerCallBack': function call missing argument list; use '&CLoggersInfra::RedundencyManagerCallBack' to create a pointer to member   I tried the suggestion to use &CLoggersInfra::RedundencyManagerCallBack - didn't work for me.   Any suggestions/explanation for this??  I'm using VS2008.  Thanks!!


Can someone tell me how to replicate this style of boxes in LaTeX, that is, to make a box of that color and style? I do not want the Remark command too. I just want a code that makes a box of that color and style, maybe change the background color of the text to lighter yellow. Thank you. You may or may not add the same text given in the below prototype

I would like to make a box like the figure below. Can you assist me with text code using tcolorbox?   Thanks


The issue is the following: I need to create a working WindowsBootUsbStick from Try Ubuntu.  I am currently using from an Ubuntu-Boot-USBStick the 'Try Ubuntu'. Which is pretty neat - I set it up to download the WIN10 iso file on one of a Fat32 partition.  After that, I need to burn a bootable USB stick from here to set up Windows. What are the commands through Terminal to create a USB stick and burn an .iso to it?   Background story: I originally tried several methods - and to make you laugh - I am sitting among different USB sticks with Win7/Win10.    First I tried to create Win10USB from MacOS with UneBootin (1) This was working until it stops at the setting up Windows 10 /Of course, I tried to solve it with different methods with BIOS/  Then I downloaded another torrent-version of Win10 and created boot USB and same procedure it gave another error(2) Then I downloaded the official one from Microsoft.com (3) and go through the same procedure.  Then I tried to choose another boot program, in that case, I created the USB-Boot from MacOS Terminal(4) - it is not even working but the creation I think pretty similar like here.   So now I need to navigate(I) from the terminal the ISO file then I need a command to create a bootable stick from there(II).   By the way, the UbuntuBoot is working properly so from here I can easily get an up and running Ubuntu but before I need Windows.   These are the partitions what I created with the 'Try Ubuntu' mode.  Device         Start       End   Sectors   Size Type /dev/sda1       2048 104974335 104972288  50.1G Microsoft basic data  /dev/sda2  104974336 167888895  62914560    30G Linux filesystem  /dev/sda3  167888896 230864895  62976000    30G Linux filesystem  /dev/sda4  230864896 976773119 745908224 355.7G Microsoft basic data   I also created a folder at the FAT32 partition at /dev/sda4 with the name of the Folder: 'Downloads' So first question:   How can I reach the .iso file from Terminal?      Then how can I create the bootable USB stick with the Win10.iso file?

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


Getting the line that splits down the variables column is giving me trouble.

I have this table, but wanted to format the first row. I like to match the two columns of first row, and last two columns of the same first row. Any suggestion on how to do that?  \begin{table}[!h]  \caption{Comparison of percentages.} \begin{tabular}{lclclclclc} \hline \hline  Mode &  Var  &  Cum\\ \hline {}       & EF   & CHF    & EF2   & CHF2\\ 1   &  17.5 & 19.1   & 17.5  & 19.1\\ 2   &  11.8 & 12.7   & 29.3  &  31.9\\ 3   &  6.6  &  5.6         & 35.9    &  37.4\\ \hline \end{tabular} \end{table}


I have an older HP Pavilion from 2007 that I have been trying to get up and running. It originally had Ubuntu 13.04, but I was experiencing crashes where the entire screen would turn into corrupted garbage (happened twice when trying to install mp3 codec). I ran a whole health check on the RAM and it passed.  I replaced it with CrunchBang Linux, and it worked fine, but it failed to connect to wireless networks (the previous Ubuntu did). So I decided to get the latest Ubuntu (fresh install). It installed fine, connected to the wireless network fine as well.  It even seemed to boot okay, showing the keyboard shortcuts splash screen. However I could move my mouse all for about half a minute, then it froze. Then after about 10 seconds it unfroze to show my mouse's new position, promptly freezing again.  Ad infinitum. I can't do squat.  Each time it updated my mouse's position, it failed to update the clock. It was frozen at 11:01am. It didn't seem like the CPU was doing anything. Also happens again after a restart.  AMD Athlon 64 X2 5200+ 3GB RAM On-board GPU roughly equivalent to NVIDIA GeForce 6150SE   tl;dr  Fresh install of 14.04 boots frozen and updates mouse every 10 seconds -- as if CPU is extremely busy and overwhelmed, but never goes back to normal. I can't do anything at all. Ubuntu 13.04 and Crunchbang didn't have this problem.  Any ideas?

I know that editing the boot options line and adding 'nomodeset' solves the problem of my laptop during LiveCD mode, what I don't know is how to set it at boot up through Grub2 after I've installed Ubuntu.  So, my question is; how do I set nomodeset before I boot into Ubuntu?


To enable CORS filter I added the following in web.xml file in webapps/Geoserver/WEB-INF  <filter>  <filter-name>cross-origin</filter-name>  <filter-class>org.eclipse.jetty.servlets.CrossOriginFilter</filter-class>    ...  <filter-mapping>     <filter-name>cross-origin</filter-name>     <url-pattern>/*</url-pattern> </filter-mapping>   After adding above, I restarted GeoServer. Now, when I access GeoServer, I get following error:  HTTP ERROR: 503  Problem accessing /geoserver/. Reason:  Service Unavailable

I hope somebody has already figured this one out. I just installed Geoserver 2.9 on a vanilla Ubuntu 16.04 distro. The Geoserver 2.8 method of enabling CORS with the shanbe.hezoun class does no longer work with Jetty 9.2.13.  There are mentions that CORS support is already packaged with Jetty 9.2.13 in the jetty-servlets.jar.  The Jetty lib which is compiled with Geoserver contains a jetty-servlet-9.2.13.v20150730.jar in geoserver/lib but not jetty-servlets.9.2.13.v20150730.jar. Are these supposed to be the same jar with a different name?  It should be possible to enable CORS either in geoserver/etc/webdefault.xml or in geoserver/webapps/geoserver/WEB-INF/web.xml.  My understanding is that the webdefault.xml is applied first and the web.xml thereafter.  I have tried following filter in both xml. I haven't got as far as adding a filter mapping. Adding the filter alone will cause the Geoserver/Jetty service to not start proper.  <filter>     <filter-name>cross-origin</filter-name>     <filter-class>org.eclipse.jetty.servlets.CrossOriginFilter</filter-class> </filter>


Can anyone tell me what's happened to the GetDeb website and repository?  Is it just a temporary problem or has been turned off permanently?

Lately, when I update, the process sticks on get deb:     [Connecting to archive.getdeb.net (144.76.200.19)]   The site -  - times out and the cloudflare message is in no way helpful.  Does anyone know why this repo and site are down? or perhaps anything else about it?  Thanks.


If f and g are entire and $\left|f(z)\right| \leq \left|g(z)\right| $ in $\mathbb{C}$ then $\exists \alpha\in \mathbb{C}$ such that $f(z)=\alpha g(z)$ $ \forall z \in \mathbb{C}$ with $\left|\alpha\right| \leq 1$   Is it possible to use without residues and so? I haven't learned neither Laurent series nor residues. This question is from a final exam so I don't know if im supposed to be able to prove it right now or i have to wait to learn those other tools before i can prove it. Any tips are appreciated.

Suppose $f$ and $g$ are entire functions, and $|f(z)| \leq |g(z)|$ for all $z \in \mathbb{C}$, Prove that $f(z)=cg(z)$.   My try :  I consider $h(z)=\frac{f(z)}{g(z)}$. If I prove that $h(z)$ is entire, using the fact that $|h(z)|\leq 1$, the result follows immediately from Liouville's theorem.  To prove that $h(z)$ is entire, I have to prove that $h(z)$ has removable singularities at possible zeros of $g(z)$.  Suppose $g(z_0)=0 \Rightarrow |g(z_0)|=0 \Rightarrow |f(z_0)|=0$, BUT what if $z_0$ be a root of of order $k$ of $g(z)$ (i.e. $f^{(n)}(z_0) = 0 $ for all $ 0 \leq n \leq k-1$) and be a zero of order $m$ of $f(z)$ and $k>m$ ?  And if that's not the case, how to rigorously show that $z_0$ is a removable singularity ?  Thank you all in advance.


Found out that having higher level allows you to naturally find and catch higher level Pokemon. If I have level 23 Pidgey (for example) and enough candy to evolve. Should I evolve the Pokemon, or wait for a higher level Pokemon so that I get a better Pidgeotto?  Is there a balance to be struck between evolving vs holding out for better level?

When activating the evolution for a caught Pokemon, it seems to amplify the Combat Power (CP). Thus it seems most beneficial to evolve your Pokemon with the highest CP, if you have multiple of the same kind.   But what I am not sure about is whether it makes an efficiency difference if you spend candies and dust to boost CP before evolving, to gain more from the amplification? Or is it more efficient to just evolve without spending, and then using the leftover candies afterwards, since they now give a bigger CP boost per candy?   I only tested with a Rattata so far, which gained +8 CP per candy before evolving, and +15 CP afterwards. I collected no numbers on the amplification efficiency though, and now ran out of materials for further testing.  Or maybe it is a balanced calculation and makes no difference at all? I would love to have some insight on that.    Some data I collected thus far: (GPC = CP gain per candy)  79 CP Weedle (GPC 6) evolved to: 84 CP Kakuna (GPC 6), evolved at 90 CP to: 297 CP Beedrill    Note: The max-CP "half circle" in the profile stayed filled roughly at the same relative position throughout the evolutions.


Since ice is less dense than water, it floats on it, we all know this. Now suppose, if ice is floating in a glass cup, when the ice melts there should be some change at water level in the glass cup. But when I found this on the internet, it states that the water level will be same. Can someone justify/explain this?  In my way, water level will decrease because ice has greater volume than water, so when it floats, it will displace some water equal to its volume for floating. But when it melts, its volume decreases and hence water level will also decrease.  Is it right or wrong what I am thinking?

I have read the explanation for this in several textbooks, but I am struggling to understand it via Archimedes' principle. If someone can clarify with a diagram or something so I can understand or a clear equation explanation that would be great.


I got to thinking about the square root the other day, and there's this thing that bugs me in the back of my mind.  As far as I know, $\sqrt{4}$ is unambiguously $2$, and nothing else, as the square root of a number is defined as the positive root of that number.  Yet, when solving algebraic equations, people (myself included) seem to follow this logic:  Solve: $x^2 = 9$  Solution:  $\sqrt{x^2} = \sqrt{9} \Rightarrow x = \pm3$   All of a sudden, people love the minus sign! But this is obviously notationally incorrect, even though $x$ really is $\pm 3$. For myself, I made a deal with myself a long time ago: square roots of numbers are always positive, square roots of unknowns always have 2 roots (at least in $\mathbb C$ (counted with multiplicity)).  This itch really needs to be scratched, driving me crazy! :) Thanks in advance.

Last year in Pre-Algebra we learned about square roots. I was taught then that $\sqrt{64}=8$ and $\sqrt{100}=10$, which I understood and accepted. I was also taught that $\pm\sqrt{64} = 8,-8$ because both of those numbers squared is 64, which I also get. But this year, with a new school and teacher in a different state, our teacher is telling us that: $\sqrt{64}=8,-8$ and $\pm\sqrt{64}$ also is $8,-8$. The way to get the positive root of something is: $+\sqrt{64}=8$ And these seem to contradict each other. I was always taught that a regular square root returned a positive number and only a positive number, but now my teacher is saying a regular square root gives two numbers, and considering the square root of a number $n$ is defined as $y^2=n$ I see where he is coming from. Upon researching this Wikipedia says:  For example, $4$ and $−4$ are square roots of $16$ because $4^{2} = (−4)^{2} = 16$  And Wolfram MathWorld says:  Note that any positive real number has two square roots, one positive and one negative. For example, the square roots of $9$ are $-3$ and $+3$  But on the other side, Wolfram Alpha, when given "The square root of 9" gives only 3.  So, which is right? Is $\sqrt{64}$ considered $8$? or is it $8,-8$?


I have two independant normally distributed random variables.  X ~ N(657, 3) Y ~ N(661, 2)  P(x > y) = ?   How do I calculate the probability of X being greater than Y? Using R for simulating, I am getting values around 0.13. How to get the exact ("theoretical") value?

Let's say I have one point that will be taken randomly from a normal distribution with mean $\mu_1$ and standard deviation $\sigma_1$.  Let's say I have another point that is taken much in the same way from another normal distribution with mean $\mu_2$ and standard deviation $\sigma_2$;.  How can I compute the probability, given $\mu_1$, $\mu_2$, $\sigma_1$, and $\sigma_2$, that my first point will be larger than the second?  I am sort of interested in the reasoning behind an "analytic" answer (or as analytic as you can possibly get with the normal distribution, which isn't that much), but I am more importantly looking for an algorithm of computing this probability, as it will be used in a simulation/model.  Does anyone know where I could get started on reasoning through this?  Note: For actual computation, having a table of values of the % of the curve within a given multiple of the standard deviation is feasible in my situation.


I have a series of photographs each taken about 3 days apart over 4 months, there are about 60 images in total. I'd like to be able to present them as an animated gif but without the subject seeming to jump around when the picture was taken from a slightly different angle. Is there software which can help?  I have access to Photoshop/Lighroom.

Do you know any open source tool to automatically align images, similar to the auto align feature in Photoshop?


As a developer, I am quite new in SEO area. I published my website 40 days ago. Before to start this goal, I read and learn much about SEO. I am still learning but actually I can not find so much thing to do more. I researched for keyword curiously that I want to get rank and some of them have low difficulty.  Semantic html with all necessary tags/attributes. SSL Speed (pagespeed score like 90) AMP (all paged completely valid even without any warning). Microdata New, unique and qualified content (once or twice a week) Most seo report sites (semrush, seobility, seositecheckup) gives me more than %90. No error or warning on GSC / Bing webmaster / Yandex webmaster Valid sitemap.xml, robots.txt Totally curious title and meta tags. Backlinks (I bought from some freelancers), I disavowed some of my spammy backlinks. Semrush gives the backlink quality %96. Valid redirects for http and non-www versions. Ahrefs gives PR 70+, DR 26+ (increasing) 100% uptime from first publish. Stellar hosting (closest servers), Cloudflare pro plan, no security issue.  These are my checklist and there are other things also I don't remember right now. I am pushing hard actually in my opinion but although I am expecting the rise, my gsc performance graph drops significantly.  What about my competitors ? For my aimed keywords, most (really most) of them in first page (event the first one) has not the %70 of my checklist (even SSL) for SEO. So, what is the point of Google? Why I could not get what I deserve instead of my competitors?

What are the best ways to improve a site's position in the Google search results?


So, to start this off. It's been almost 3 years since my family and I have had our gamecube hooked up. We could never find our power cord for it, so of course, we assumed we lost it. We kept trying to find another one. Never could, until tonight. I found our power cord in a tin bucket in our basement, and bought one of those video/audio cords are Jay's CD's and Hobbys. I thought it'd be a nice suprise for my mother on Christmas since her and I are huge Zelda fans and have not been able to play our games in awhile.  I finally have everything hooked up, and thankfully it turns on, but the color is in black and white and there's no sound. As you see in the picture, if it has hopefully shown up, that I only have the colors yellow and red hooked up, because I only have 2 middle pieces that connect them. So I'm thinking that it's only lacking color and audio because I don't have the whites hooked up, but I wanted to ask and make sure. Any comments revolving around this issue, would be greatly appreciated. Thank you.

I connected my Gamecube to my HDTV using a PS3 composite cable (shown below). However, the image displayed is blurry, in black and white, and without sound. The cable fits perfectly on the analog AV out port, so I'm not sure whether this is a problem of incompatibility. Before buying a new cable I was wondering: are there any known issues when connecting Gamecubes to newer TVs? Does the Gamecube composite output have some proprietary hardware that will only allow Nintendo AV cables to work with the console?


I have two render camera objects in the scene, about to be three, I'd like to know how to switch between them as when I hit zero, it only enters the view of my frontal camera(the first one I placed.) is it possible to switch between them?

I have multiple cameras in a scene. What I want to do is to change which one is active. This way I can view the scene from different angles. How would I do this?


On the default FBA Login Page, when a user enters wrong username/password an error message gets displayed:     "The server could not sign you in. Make sure your Username and   Password are correct, and then try again.".   I want to change this error message dynamically according to requirement.   Such as      'Invalid Username or Password', 'Your account has been locked'

On the default FBA Login Page, when a user enters wrong username/password an error message gets displayed:      "The server could not sign you in. Make sure your Username and Password are correct, and then try again.".    I want to change this error message to simple text      "Invalid Username and Password".    How can I achieve this?


I would like to write a rule to find all the public unused functions in a project. I have copied and amended the original UnusedPrivateMethod to work. But alas it works too good and finds ALL the public functions in the project.  It does so because public functions are usually called from other classes and the scope of the Rule seems to be at class level. So within each class the public functions are not used and so is part of the result.  Thus the question of how can I write a rule with a context that is on a  project level instead of just at the class level?

How can I find any unused functions in a PHP project?  Are there features or APIs built into PHP that will allow me to analyse my codebase - for example , ?  Are these APIs feature rich enough for me not to have to rely on a third party tool to perform this type of analysis?


I'm learning about regression models via Andrew Ng's Coursera course. I have a question regarding automatically finding a good model.  Does it make sense (my guess is no) to iteratively add terms, or iteratively change a model to a different one, and then check the $R^2$ or MSE and see which one is best?  For example, if you have model like y = ax + b, and then you change it to $y = ax^2 + b$ and then $y = ax^2 + ax + b$, and keep doing so while continuously checking if it's better or worse than the other models.   Like I said, I'm just beginning learning this stuff, so I'm sure there's a better way to do this, but this just popped into my head as a possibility.

I would like to implement an algorithm for automatic model selection.  I am thinking of doing stepwise regression but anything will do (it has to be based on linear regressions though).   My problem is that I am unable to find a methodology, or an open source implementation (I am woking in java). The methodology I have in mind would be something like:   calculate the correlation matrix of all the factors pick the factors that have a low correlation to each other remove the factors that have a low t-stat add other factors (still based on the low correlation factor found in 2.). reiterate several times until some criterion (e.g AIC) is over a certain threshold or cannot or we can't find a larger value.   I realize there is an R implementation for this (stepAIC), but I find the code quite hard to understand. Also I have not been able to find articles describing the stepwise regression.


We know that using cd <directory> will open the directory, if it exists!  Also, cd .. will take us up one level from the current working directory.  But, when we have a nested dir with longer path like /home/thina/teams/td/tech/app/release/apks, it is tiring to just go into the folder apks and also it is hard to get back to another node, say here /home/thina/teams.   Is there any way to skip the typing of cd and cd ..? I'm using Ubuntu 16.04.

Every time I wish to move to a directory I use very often, I must type this long directory path:  cd /media/prasanth/01D0F888E7BC91801/github projects   or I must use the gui to get into the folder and open the terminal.  Is it possible to assign this long path to a single name and enter it via the terminal like  cd mygitfiles   ?


I'm running Ubuntu 20.04 LTS and I want to create a Windows 10 bootable USB for someone, but when I tried the different ways to get Woe USB running, it seems like it's not yet supported on Ubuntu 20.04 LTS. Is there another GUI tool that runs on Ubuntu that flashes Windows 10?  MultiWriter just resulted in "no bootable disk" upon starting PC. WoeUSB keeps giving errors upon installing. Etcher does not support it, but even after I attempted to do so, "no bootable disk found."  I am not looking for terminal-based solutions, rather GUI applications to flash Windows, and I'd appreciate any pointers.

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


Is there a non jailbreak firewall for the iPhone or is there some way to set one up, somehow?

Does iOS support a built-in firewall like macOS does? I don't see anything about it in Settings.


I've been trying to calculate the electric field of an infinite sheet via the differential form, i.e. using \begin{align} \nabla\cdot\text{E}=\frac{\rho}{\epsilon_0}. \end{align} I am aware the answer is \begin{align} \text{E}=\frac{\sigma}{2\epsilon_0}\hat{n}, \end{align} as well as how to use Gauss's law to arrive at it, but I am having trouble matching it without Gauss's law. The charge distribution is \begin{align} \rho=\sigma\delta(z). \end{align} Since the sheet is infinite the electric field only points in the $z$ direction, \begin{align} \frac{\mathrm d\text{E}_z}{\mathrm dz}=\frac{\sigma}{\epsilon_0}\delta(z). \end{align} Integrating gives that \begin{align} \text{E}_z=\frac{\sigma}{\epsilon_0}. \end{align} Which is missing a factor of 1/2. Perhaps I am going wrong with my integration, as the delta function must be integrated around the point in order for it to output 1, \begin{align} \int_{a-\varepsilon}^{a+\varepsilon}\delta(z-a)\mathrm dz=1, \end{align} which makes me suspicious of my indefinite integration. Perhaps the correct methodology may lie in using Heaviside step function, as I believe H$(0)=1/2$ depending on who you ask, \begin{align} \rho&=\sigma\frac{\mathrm d}{\mathrm dz}\mathrm H(z)\\ \mathrm H(z)&=\int_{-\infty}^z\delta(s)\mathrm ds, \end{align} but when I try that I get \begin{align} \mathrm E_z=\frac{\sigma}{\epsilon_0}\mathrm H(z), \end{align} and I can't justify evaluating both sides at 0.

A classic textbook E&M problem is to calculate the electric field produced by a point charge $Q$ located at $(\mathbf{r}_0,z_0)$ inside a medium with two semi-infinite dielectric constants defined as  $$\epsilon = \epsilon_1  \,\,\,\,\left[ \textrm{ For }z>0 \right]\\\epsilon = \epsilon_2  \,\,\,\,\left[ \textrm{ For }z<0 \right]$$  The clever solution is to use the method of images to satisfy the boundary condition at $z=0$ and then use the uniqueness of Poisson's equation to argue you got the right answer.  The method of images works nicely for a discrete set of boundary conditions, but a student asked me about the case of a point charge $Q$ located at $(\mathbf{r}_0,z_0)$ inside medium with a continuous dielectric function $\epsilon(z)$.  I suppose one could try to make an infinite series of "method of images" charges to solve the problem, but that seems like a roundabout way to go about it.  The alternative is to work directly with Maxwell's equations  $$\nabla\cdot(\epsilon(z) \mathbf{E}(\mathbf{r},z)) = 4\pi \delta(\mathbf{r}-\mathbf{r}_0) \delta(z-z_0)\\ -\nabla\cdot(\epsilon(z) \nabla\phi(\mathbf{r},z)) = 4\pi \delta(\mathbf{r}-\mathbf{r}_0) \delta(z-z_0)\\ $$  My question is: can we still write down a neat formal solution for the potential (or electric field) in terms of  $\epsilon(z)$?   I suppose there might be some clever way to make the method of images help us to invert this equation, but it definitely isn't clear. Additionally, since this is a 1D problem, I think the solution should be possible in terms of some convolution integral, but again I am not entirely sure about that.


Title of the question is pretty simple, I have 18000 site collections and this script is showing 1GB of ram used, so I wonder how can I dispose correctly the spweb and spsite object  $webapplication =  Get-SPWebApplication  http://xxx foreach($site in $webapplication.Sites) {               foreach($subWeb in $site.AllWebs)     {         if($subWeb.AllProperties["WebTemplate"] -eq "Client" -or $subWeb.AllProperties["WebTemplate"] -eq "Job")         {             if($subWeb.AllProperties["WebTemplate"] -eq "Client")            {                 $infoList  = $subWeb.Lists["Client Info"]            }             if($subWeb.AllProperties["WebTemplate"] -eq "Job")            {                 $infoList  = $subWeb.Lists["Job Info"]            }             if($infoList -ne $null)            {                              $InfoItem = $infoList.Items[0]                if($InfoItem -ne $null)                {                   $clientCode = $InfoItem["Client Code"]                    $quicklaunchnavigationnodes= $subWeb.Navigation.QuickLaunch                   foreach($navNode in $quicklaunchnavigationnodes)                   {                       if($navNode.Title.Contains("Tax Invoices"))                       {                         $clientcodefromurl = $navNode.Url.Substring($navNode.Url.IndexOf("=")+1,8)                          if($clientCode -ne $clientcodefromurl)                         {                             Write-Host 'Processing  site ' $subWeb.Url                              Write-Host '  Info list found for ' $subWeb.Url                              Write-Host '  Info item found '                             Write-Host '    Client code from url: ' $clientcodefromurl                                                       Write-Host '    There is a difference' -ForegroundColor Red                              Write-Host '    Incorrect Navigation Url: ' $navNode.Url                                                        Write-Host '    New Url: ' $navNode.url.Replace($clientcodefromurl, $clientCode)                             #$navNode.url.Replace($clientcodefromurl, $clientCode)                             #$navNode.Update()                             Write-Host '    Url updated' -ForegroundColor Green                          }                       }                                   }                }                else                {                      Write-Host '  Info item not found '$spWeb.Url                 }                       }             else            {                Write-Host 'Info list not found for ' $subWeb.Url             }           }         } }

I have a code that loops through all the Sites and Webs in a web application.  My code uses for..each loop to navigate through each site and web object.  I was wondering if we are required to dispose the SPWeb and SPSite objects when used inside a loop.  Codes:-  foreach (SPSite thisSite in siteAuditWebApplication.Sites) {  //My operation here  }  Similar to the above code I also have some part of code that loops through all the Web and Lists.  Do we have any best practice for disposing objects inside the loop,  or do i really need to take care about disposing the objects?  Thanks in Adv.. Sudhir


How many values of N exist, such that N! ends with exactly 30 zeros?

Possible Duplicate:          I know that I have to find the number of factors of $5$'s, $25$'s, $125$'s etc. in order to do this. But how can you derive such a formula for any number $n$?


Let $f : [0,1] \to \mathbb{R}$ be continuous function, such that it takes any value finitely many times and $f(0) \neq f(1)$, then does there exist a point $r_{0}$ in the range such that the cardinality of $f^{-1}(r_{0})$ is odd? (Note that the domain is compact.)  I feel that the answer is affirmative but not been able to come up with any concrete argument. I feel this because, as the function is continuous on $[0,1]$, it would attain its maximum and minimum. With out loss of generality, we can assume that the minimum is attained at $0$ and maximum is attained at $1$. In between, $0$ and $1$ it might oscillate any number of times. But the number of times minimum is attained and maximum is attained must have different parity.

Suppose $f: \mathbb{R} \rightarrow \mathbb{R}$ is continuous. Is it possible for $f$ to assume each value in its range an even number of times?  To clarify, some values might be taken 0 times, some 2, some 4, etc., but always an even (and therefore finite) number. I don't require that there be a value that is assumed any particular number of times.  For example, the function might be surjective, or never take on any value exactly twice.  This question is possibly the same as . That question may instead have meant, "If $n$ is even, is it possible for $f$ to assume every value in its range exactly $n$ times?"  In any event, it has not been answered.


Below are 2 ways of declaring javascript functions.  Method 1:  function pollingLoop(req, res) {     // Function Body }   Method 2:  var pollingLoop = function() {     // Function Body }   What is the difference between the 2 functions?

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


For the past five years, 10 months my default Stack Exchange profile "identicon" has been an orange color. However, suddenly within the past few days it turned green.    Current Color:    Why did it suddenly turn green, and how do I get the original one back?

When I first signed up on a Stack Exchange site and got a profile image, it was this one (see my current user card I'm actually not sure what I look like any more):     Later, I got  and SEDE profiles, and my user image there was a different identicon. Because . I would have a picture of it, but that's the problem. ... Thanks to , I have a picture:     On those two sites, it changed from that purple one to this new one recently:   I don't know when the change happened exactly, but I KNOW I didn't change it (I don't know how to change it, otherwise I would have changed it to my main pink one).  Why did this change? Can I get my other icon back or will I be stuck with this new one?   Also, are the gravatars at Area 51 and SEDE securely generated?    After looking in my profile settings, I really confused (I am seeing my wrong avatar in more and more places since I first posted this.):        Seriously.......    What...?    (I'm using this , but be warned that they will try to IP block you after a certain number of requests to force you to pay... May look for a better alternative later.)


I'm travelling to Spain for business purpose and my visa is valid for just 14 days. Now I have another very urgent business to attend to in the Netherlands. Can I extend my stay for another 10 days to complete my business meeting in the Netherlands?  Can I get an extension in Spain, prior to entering the Netherlands? I haven't left for Spain yet and currently staying in my residence country (India).

My daughter applied at the Italian Consulate in Philadelphia, and they gave her two entries for 20 days (we thought it was for 20 days each entry). She was in Italy 12 days, then went to England for 1 week and flew to Venice to take a 10-day cruise. She couldn't make it because they said she has only 8 remaining days, but she still has a land tour already paid this week.  What can she do? Can she extend the Schengen visa for 12 more days? Right now, she is in Madrid, but next week she has to fly from Barcelona to Paris to start with the tour. What would happen if she decides to take the tour with the expired visa? She is a US permanent resident.


I want to install two PHP versions on a single server . I have PHP v7.1 installed on my server and i want to install another version that is php5.5 on my server.   I tried installing v5.5 but it either upgrades from the previous version or it does not get installed because of the previous version .  What commands should i use to install an additional phpv5.5 (having phpv7.1 already installed) on my server.  I'm using centos 6.8

I need to test my PHP applications with multiple versions of PHP 5.x, such as PHP 5.0.0 and PHP 5.2.8.  Is there a way that I can configure a development LAMP server so I can quickly test applications with multiple versions of PHP5?


Let $a_n$ and $b_n$ be two sequences defined by the recurrence relation  \begin{align} a_{n + 1}  = \frac{{1 + a_n  + a_n b_n }}{{b_n }},\qquad b_{n + 1}  = \frac{{1 + b_n  + a_n b_n }}{{a_n }} \end{align} with $a_1=1$ and $b_1=2$. Find $\mathop {\lim }\limits_{n \to \infty } a_n$.    Simple manipulations yield that  \begin{align} a_n  = \frac{{1 + b_n }}{{b_{n + 1}  - b_n }},\qquad b_n  = \frac{{1 + a_n }}{{a_{n + 1}  - a_n }} \end{align} I tried to find the first few terms of $a_n$ and $b_n$ but it seem that they doesn't have a general form.  Once can see that both sequences increasing fast and randomly.  Also, I tried to insert $b_n$ in $a_n$, but I got a complicated result and it doesn't help or indicate to anything.  Any help is appreciated. Thanks

I'm given two sequences:  $$a_{n+1}=\frac{1+a_n+a_nb_n}{b_n},b_{n+1}=\frac{1+b_n+a_nb_n}{a_n}$$  as well as an initial condition $a_1=1$, $b_1=2$, and am told to find: $\displaystyle \lim_{n\to\infty}{a_n}$.  Given that I'm not even sure how to approach this problem, I tried anyway. I substituted $b_{n-1}$ for $b_n$ to begin the search for a pattern. This eventually reduced to:  $$a_{n+1}=\frac{a_{n-1}(a_n+1)+a_n(1+b_{n-1}+a_{n-1}b_{n-1})}{1+b_{n-1}+a_{n-1}b_{n-1}}$$  Seeing no pattern, I did the same once more:  $$a_{n+1}=\frac{a_{n-2}a_{n-1}(a_n+1)+a_n\left(a_{n-2}+(a_{n-1}+1)(1+b_{n-2}+a_{n-2}b_{n-2})\right)}{a_{n-2}+(a_{n-1}+1)(1+b_{n-2}+a_{n-2}b_{n-2})}$$  While this equation is atrocious, it actually reveals somewhat of a pattern. I can sort of see one emerging - though I'm unsure how I would actually express that. My goal here is generally to find a closed form for the $a_n$ equation, then take the limit of it.  How should I approach this problem? I'm totally lost as is. Any pointers would be very much appreciated!  Edit:  While there is a way to prove that $\displaystyle\lim_{n\to\infty}{a_n}=5$ using $\displaystyle f(x)=\frac{1}{x-1}$, I'm still looking for a way to find the absolute form of the limit, $\displaystyle\frac{1+2a+ab}{b-a}$.


this is the first time I ask question here. I'm working on an rather small project that implement web chat using jsp and servlet. But I encounter a problem. I set an attribute in servletcontext using this   if(sc.getAttribute("queue")==null)  //sc is servletcontext     {           sc.setAttribute("queue", new       TreeMap<String,LinkedList<TreeMap<String,String>>>());     }   then I create a map in the attribute by this  if(sn.getAttribute(sn.getId())==null) //sn is a HttpSession object     {         //store nickname         sn.setAttribute(sn.getId(),request.getParameter("nickname"));          //store the new entry in Context         sc.setAttribute("queue",((TreeMap<String,LinkedList<TreeMap<String,String>>>)sc.getAttribute("queue")).put(sn.getId(),new LinkedList<TreeMap<String,String>>()));     }   I know the code isn't so elegant. It's my first time to really work on a project. The important thing now is that it can work.  All above is in my servlet file. Next I want to call a function which has the format as this “public static TreeMap>> messagePut(ServletContext sc)”     public static TreeMap>> messagePut(ServletContext sc)   Sorry there is some problem in the dispaly of the TreeMap, please see the concrete code above.  The discreet implementation is   public static TreeMap<String,LinkedList<TreeMap<String,String>>> messagePut(ServletContext sc) {     //obtain message queue             TreeMap<String, LinkedList<TreeMap<String,String>>> temp=(TreeMap<String, LinkedList<TreeMap<String, String>>>)(sc.getAttribute("queue"));              //iterate             Set<String> keset=temp.keySet();             Iterator<String> it=keset.iterator();                TreeMap<String,LinkedList<TreeMap<String,String>>> mm=((TreeMap<String,LinkedList<TreeMap<String,String>>>)sc.getAttribute("queue"));              //object store stores a reproduce of the whole message queue             TreeMap<String,LinkedList<TreeMap<String,String>>> store=(TreeMap<String,LinkedList<TreeMap<String,String>>>)sc.getAttribute("queue");             while(it.hasNext())             {                  //put the message into queue                 //temp2 is user nickname                 String temp2=(String)it.next();                 if(temp2.equals(name))                     continue;                 else                 {                     TreeMap<String,String> c2=new TreeMap<String,String>();                     c2.put(name,message);                     LinkedList<TreeMap<String,String>> c3=store.get(temp2);                     c3.add(c2);                     store.put(temp2,c3);                 }              }              return store; }   I got a NullPointer exception in the above, this statement:  Set<String> keset=temp.keySet();   throw a nullpointer exception, I don't know why. But I have some doubt about this statement :  sc.setAttribute("queue",((TreeMap<String,LinkedList<TreeMap<String,String>>>)sc.getAttribute("queue")).put(sn.getId(),new LinkedList<TreeMap<String,String>>()));   TreeMap>> is TreeMap<String,LinkedList<TreeMap<String,String>>>. I don't know whether this statement is correct.

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


I have following html
    Click me    <select>        <option value="1" selected="selected">1</option>        <option value="2">2</option>        <option value="3">3</option>        <option value="4">4</option>    </select>
   jQuery:  $('span').on('click', function () {    $('select').focus();  });   What I want to do is when I click on span tag the select menu needed to be focused and dropped down without changing the structure. I spent hours to find a solution for this but I couldn't.

How can you programmatically tell an HTML select to drop down (for example, due to mouseover)?


I've looked at hmmlearn but I'm not sure if it's the best one.

What stable Python library can I use to implement Hidden Markov Models? I need it to be reasonably well documented, because I've never really used this model before.  Alternatively, is there a more direct approach to performing a time-series analysis on a data-set using HMM?


I was on a public Wifi. When I returned home, reconnecting to my network, a panopli of numbers appeared on the network for 3 seconds. Then my network went after that. Going on google, I received a message saying that my iPhone was in danger, that someone was watching what I was doing. Is this a scam? Because I wasn’t on this page, I was on Time2Watch. I would like to have sincere answers please, I would not want to be spied on. Here are some pictures of the images that '' google or the scam '' sent me.  Thank you !!!

I got a notification on my iPhone. The notification reads     Someone might be watching what you browse. Follow 3 steps to encrypt your web traffic and change your IP address.   What does this mean?


Here is my code. the output should be 32.9. But it seems showing      Exception in thread "main" java.lang.NullPointerException     at   ArrayLocation.main(ArrayLocation.java:14)     public class ArrayLocation {     private double coords[];      public ArrayLocation(double[] coods){         this.coords=coords;     }      public static void main(String[] args){         double[] coords={5.0,0.0};         ArrayLocation accra= new ArrayLocation(coords);         coords[0]=32.9;         coords[1]=-117.2;         System.out.println(accra.coords[0]);     } }


I have several images I want to crop in batch. They are scans and have "jagged edges". Basically I just want a 95% crop in both directions with the crop frame perfectly centered. So if the image is 1000x1000, I want a 950x950 image with 25 pixels cropped from each side. I don't see a way to specify this in Photoshop or Lightroom. Note: I do NOT want to straighten or resize the image.

I've got a batch of photos (an owl coughing up a pellet in case you're curious).  I want to make an animated GIF out of them, but the result would be improved if they were all given an identical crop first.  I'm currently using Picasa for my basic photo editing on a Windows 7 PC.  While Picasa does have batch editing, crop is not one of the items on the batch menu.  Does Lightroom have a batch crop?  If there's a way to get Picasa to show me the coordinates of the crop selection rectangle, I could also use that information to do the same crop repeatedly.  Are there any tools that let you crop an animated GIF?  I know I can create the animated GIF by uploading the component images to Google+ and then looking in the Auto Awesome area. I don't know about tools for working with animated GIFs.


On a forum we argued about the usage (or not) of an abbreviation. I said : MSORPG isn't a very used term. See my search with Google (94 results) :  The one with whom I argued replied : "Look, it is used a lot !" (14,300 results).  What can explain we have so much difference in our number of results? I haven't checked any filter able to reduce my results (I think !).

That's kind of a recursive Google Search that should be self-explanatory. It did take me some time to tweak the sentence and trying to find a number which would correspond precisely, the reason why I changed it to "hundreds" instead! :P  If you have used Google long enough you certainly have stumbled on situations similar to this, many times. Whenever it shows less than 10 pages it's quite easy to see it. The point is: the number of results on any page except the last one seems like a terrible estimate.  What's even weirder,  the estimate suddenly becomes much better and almost exactly the same on all pages than it is on the last page - the only page that's always correct.  So, anyone knows why?


A practice Math Subject GRE asked me to compute $\sum_{k=1}^\infty \frac{k^2}{k!}$. The sum is equal to $2e$, but I wasn't able to figure this out using Maclarin series or discrete PDFs. What's the most elementary way to solve this? Thank you.

For some series, it is easy to say whether it is convergent or not by the "convergence test", e.g., ratio test. However, it is nontrivial to calculate the value of the sum when the series converges. The question is motivated from the simple exercise to determining whether the series $\sum\limits_{k=1}^{\infty}\frac{k^2}{k!}$ is convergent. One may immediately get that it is convergent by the ratio test. So here is my question:     What's the value of $$\sum_{k=1}^{\infty}\frac{k^2}{k!}?$$


I'm Vishal Nagda from India. I've basic knowledge of Python & C programming language, and I want to develop Ubuntu applications & also wishes to join Ubuntu Community. So I want to ask you that what requirements and qualifications I needed to fulfill my wishes.  Thanks.

I would like to know what kinds of contributions someone can make to Ubuntu. Such as Programmer, User, Proofreader, etc.


When I try to upgrade from Ubuntu 19.04 I get the following error message: An upgrade from 'disco' to 'focal' is not supported with this tool. === Command detached from window (Sat Aug 15 11:21:17 2020) === === Command terminated with exit status 1 (Sat Aug 15 11:21:27 2020) ===

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


Can I estimate my road bike tyre pressures by pressing my thumb into the tyre? I don't have a tyre pressure gauge, and feel that the tyres on my new Merida Scultura are pumped too hard.

I would like to tell if my tires are correctly inflated, in this case road tires, but I do not have a pressure gauge.  Is there a handy heuristic for checking the pressure? Could I do it, for example, by trying to squeeze the tire between two fingers and seeing how easily it gives? (I can do that anyway, but it wouldn't give me any idea about the pressure level.)


Which of the following is correct?      There has to be rules and regulations.     There have to be rules and regulations.

Which is the correct form of the sentence?      There has been many instances of outbreaks in vaccinated populations    vs.     There have been many instances of outbreaks in vaccinated populations?   The question that this is supposed to be a duplicate of does not mention there has or there have. We have many learners here who are not going to be able to deduce much of anything from it.


Can we find a Borel measurable function $f:\mathbb{R} \rightarrow (0,\infty)$ such that $\int \mathcal{X}_I f d\mu = \infty$  for every nonempty open interval $I \subset \mathbb{R}$, where $\mu$ is the Lebesgue measure on $\mathbb{R}$ ? I think the answer is true; there is such a function, but with this condition "integral = infinity" this makes $f$ is unbounded almost everywhere, so not sure how to define it, if it exists.

Let $f : \mathbb R^n \rightarrow \mathbb R$ be a measurable function.  We know that $f$ is not necessarily locally integrable - but how hard can a measurable $f$ fail to be so? For example, is it true that $f$ is locally integrable outside of a negligible set $N \subset \mathbb R^n$?   Edit: In consideration of the comment by zhs, let me correct the phrasing of the question. I was originally wondering whether the 'singular' behaviour of a measurable function can be localized to a 'small' set.   A motivational example is $f(x) = 1/x$ over the real line. It is locally integrable in the complement of the origin. Hence, a conceivable phenomenon, which I had in mind originally when asking the question, could be that a measurable $f$ is integrable over open sets that are compactly contained in the complement of some negligible sets.


A program reports this error:     Error libXfixes.so.3: cannot open shared object file   How can I resolve this? Thanks!

I often find myself wanting to install something, but I'm unsure of what package it's in. This is a very common occurrence for me:  $ make html sphinx-build -b djangohtml -d _build/doctrees   . _build/html make: sphinx-build: Command not found make: *** [html] Error 127  $ sudo apt-get install sphinx E: Unable to locate package sphinx  $ sudo apt-get install sphinx-build E: Unable to locate package sphinx-build   googles  $ sudo apt-get install python-sphinx   Is there a better way?


I would like to list all commands available in $PATH.  Any idea ?

What can I type at my shell (which happens to be bash) that will list all the commands that are recognized?  Also, does this differ by shell? Or do all shells just have a "directory" of commands they recognize?  Secondly, different question, but how can I override any of those? In other words how can I write my own view command to replace the one existing on my Ubuntu system, which appears to just load vim.


I am getting an issue while running a cron job for exporting all databases on my Godaddy Shared hosting Cpanel account. But I have trouble finding the syntax error in below command.  Same command is working on my AWS Ec2.  mysql -N -ubackup -pt -e 'show databases' | while read dbname; do mysqldump -ubackup -p123 --complete-insert -N "$dbname" > /home/test/sqlbackups/'$(date +"%Y-%m-%d")-$dbname'.sql;done   Error Received on Mail:  /bin/bash: -c: line 0: unexpected EOF while looking for matching `'' /bin/bash: -c: line 1: syntax error: unexpected end of file

I want to create a log file for a cron script that has the current hour in the log file name. This is the command I tried to use:  0 * * * * echo hello >> ~/cron-logs/hourly/test`date "+%d"`.log   Unfortunately I get this message when that runs:  /bin/sh: -c: line 0: unexpected EOF while looking for matching ``' /bin/sh: -c: line 1: syntax error: unexpected end of file   I have tried escaping the date part in various ways, but without much luck. Is it possible to make this happen in-line in a crontab file or do I need to create a shell script to do this?


My iPhone restarts "randomly" when the battery is below a certain threshold (which I haven't been able to specifically pinpoint). A couple weeks ago I had the battery replaced with a new one, as battery life wasn't longer than just a couple of hours  The device has iOS 10.2.1, to be upgraded to 10.3 hopefully during the day.  Any ideas of what could be wrong? I've read suggestions about resetting the iPhone, but just sound like a pretty rough/brute solution to implement, although it's an alternative indeed.

Today I was walking using my iPhone 6S running iOS 9.3 as a pedometer and it shutdown.   When I got home and plugged it in, it said 30% capacity.   That seems strange. I would expect it for 2% or 5% to preserve RAM, but 30%? Maybe there is a setting I don't know about.   My question is: Why does my iPhone power off when the battery is down to 30%?   Edit: this is not a duplicate of the low battery crash as I witnessed the low power shutdown and it was not a crash.


I'm dynamically creating a Lightning Component to display a link. The link is on a field on the record. This component will be called from a parent component that exists on the Record Detail page (on the community record detail page). The problem is that this dynamically created component doesn't seem to get the recordId from the detail page.    Component markup:    <aura:component access="global" implements="force:hasRecordId" controller="My_Controller">      <aura:attribute name="myLink" type="string"/>     <aura:handler name="init" action="{!c.doInit}" value="{!this}"/>      Component works     <aura:if isTrue="{!v.myLink}">         Click my link!     </aura:if> </aura:component>   Component controller:    doInit : function(component, event, helper) {     var recordId = component.get("v.recordId");     if (recordId){         var action = component.get("c.getMyRecord");         action.setParams({objId: recordId, fields: "MyLink__c"});         action.setCallback(this, function(response){             var state = response.getState();             if (state === "SUCCESS"){                 var record = response.getReturnValue();                 var link = record.MyLink__c;                 component.set("v.myLink", link);             }             else{                 console.error("Failed with state: " + state);             }         });         $A.enqueueAction(action);     } }       The component works, I can see the text. But there is no value in myLink. Using the Chrome debugger I see that it fails because recordId is undefined. So is this a thing, dynamically created components don't get the RecordId, even thought they implement="force:hasRecordId"?

I am looking for verification/documentation on force:hasRecordId. It appears from my experience that recordId is only provided to the "container" component, and it does not feed down to any child components without explicitly passing the value.  Is that right?  BTW, I've read  They don't address my question.


I'm trying to build a project with the  using Cmake.  I'm not sure whether it is a problem with CMake or any other specifics related to the code that I'm missing out. I have implemented all the functions that I have defined and have written a CMake script as explained in the  and still get the following error. can anyone please help?  CMakeFiles/book.dir/main.cpp.o: In function `main': main.cpp:(.text+0x11): undefined reference to  `LinkedList<int>::LinkedList()' main.cpp:(.text+0x2b): undefined reference to  `LinkedList<int>::insert(int const&)' main.cpp:(.text+0x45): undefined reference to  `LinkedList<int>::insert(int const&)' main.cpp:(.text+0x5f): undefined reference to  `LinkedList<int>::append(int const&)' main.cpp:(.text+0x6b): undefined reference to  `LinkedList<int>::print() const' main.cpp:(.text+0x7c): undefined reference to  `LinkedList<int>::~LinkedList()' main.cpp:(.text+0x8f): undefined reference to  `LinkedList<int>::~LinkedList()' collect2: error: ld returned 1 exit status make[2]: *** [book] Error 1 make[1]: *** [CMakeFiles/book.dir/all] Error 2 make: *** [all] Error 2      The class declaration is the following code,  #ifndef BOOK_LINKEDLIST_H #define BOOK_LINKEDLIST_H  template <typename E> class Link { public: E element; Link *next; Link(const E &ele, Link *n= nullptr) {     element = ele;     next = n; } Link(Link *n = nullptr) {     next = n; } }; template <typename E> class LinkedList { private: Link<E> *head; Link<E> *tail; Link<E> *curr; int count;  void init();  void removeAll();  public: LinkedList(); ~LinkedList();  void print() const ; void clear();  void insert(const E &item); void append(const E &item); };  #endif //BOOK_LINKEDLIST_H   The class definition is the following code,  #include "LinkedList.h" #include "cstdio"  template<typename E> void LinkedList<E>::removeAll() { while (head != nullptr) {     curr = head;     head = head->next;     delete curr; } }  template<typename E> void LinkedList<E>::init() { head = tail = curr = new Link<E>; count = 0; }   template<typename E> LinkedList<E>::LinkedList() { init(); }  template<typename E> LinkedList<E>::~LinkedList() {removeAll();}  template<typename E> void LinkedList<E>::print() const { printf("List: \n"); Link<E> *temp = head; while(temp != nullptr) {     printf("%d ", temp->element);     temp = temp->next; } printf("\n"); }  template<typename E> void LinkedList<E>::clear() {removeAll(); init();}  template<typename E> void LinkedList<E>::insert(const E &item) { curr->next = new Link<E>(item, curr->next); if (tail == curr) tail = curr->next; count++; }  template<typename E> void LinkedList<E>::append(const E &item) { tail = tail->next = new Link<E>(item, nullptr); count++; }   Thanks.

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I understand that C14 decays at a given rate. I also interpret this to mean that 100% of the atoms of C14 in an object will all decay at the same right, individually.  So if I have 4 C14 atoms, will they all be gone in a full-life? or will two be 100% in a half-life while the other 2 are 0%?  Please explain how the decay of C14 works.

Carbon-14 has a half-life of 5,730 years.  That means that after 5,730 years, half of that sample decays.  After another 5,730 years, a quarter of the original sample decays (and the cycle goes on and on, and one could use virtually any radioactive isotope).  Why is this so?  Logically, shouldn't it take 2,865 years for the quarter to decay, rather than 5,730?


This is a question I faced in analysis. (Specifically, Lebesgue theory)  Suppose $n_k $ is a strictly increasing sequence of positive integers. Let $$E: =\{ x \in (-\pi, \pi):\, \lim_{k \to \infty} \sin(n_k x)\text{ exists}\}.$$  Show that $|E|=0$.  Not only this question, I want to know about general methods (or strategies) to show that some space has measure zero. What methods can I use to show it?

I am trying to work through Rudin. This is a question from chapter 11:     Suppose that $\{n_k\}$ is an increasing sequence of positive integers and $E$ is the set of all $x$ in $(-\pi,\pi)$ at which $\sin(n_kx)$ converges. Prove that $E$ has Lebesgue measure zero. Hint: For every subset $A$ of $E$, $\int_A \sin (n_kx) dx$ tends to zero, and $2\int_{A} \sin^2 (n_k x)dx$ tends to the measure of $A$.   So, if I can use the hint, I'm pretty sure I can get the question. The thing is, I have no idea how to prove the hint.   Using the hint, here's how I think you do the question:  Define $f$ on $E$ as  \begin{align*}f(x)= \lim_{k\rightarrow \infty} \sin(n_kx) \end{align*} Notice that $\sin(n_kx)\leq 1$, and $1\in L$ on $A\subset E$ for every measurable $A$ (since $E$ has finite measure), so Theorem $11.32$ in Rudin (the Lebesgue dominated convergence theorem) says \begin{align*} \int_A f(x) dx = \int_A \lim_{k\rightarrow \infty} \sin(n_kx) =  \lim_{k\rightarrow \infty} \int_A \sin(n_kx) = 0 \end{align*} (by the first hint). But this was true for all $A\subseteq E$, so by one of the questions on the last assignment, $f(x)=0$ almost everywhere on $E$ and so $f^2(x)=0$ almost everywhere on $E$. Using Theorem $11.32$ again, we get \begin{align*} \mu(A) = \lim_{k \rightarrow \infty} \int_A 2\sin^2(n_kx) = 2\int_A \lim_{k\rightarrow \infty}  \sin^2(n_kx)= 2 \int_A f^2(x)=0 \end{align*} Therefore $\mu(E)=0$.   Does anybody know how to prove the hint? Thanks!


I am working on an information security course and have an element of code that I need to understand:  "\x66\x68\xb0\xef". # PORT   My understanding is that this should translate to an integer value > 1024 but Im not sure how to calculate this.  I can see this string contains separated HEX values so tried printing the respective HEX values that are separated by \x and get the following:   >> print (int('66',16)) 102 >>> print (int('68',16)) 104 >>> print (int('b0',16)) 176 >>> print (int('ef',16)) 239   Obviously this gives me four separate values, so is not what I need, which is a single integer value.

How can I convert a string of bytes into an int in python?   Say like this: 'y\xcc\xa6\xbb'  I came up with a clever/stupid way of doing it:  sum(ord(c) << (i * 8) for i, c in enumerate('y\xcc\xa6\xbb'[::-1]))   I know there has to be something builtin or in the standard library that does this more simply...  This is different from  for which you can use int(xxx, 16), but instead I want to convert a string of actual byte values.  UPDATE:  I kind of like James' answer a little better because it doesn't require importing another module, but Greg's method is faster:  >>> from timeit import Timer >>> Timer('struct.unpack("<L", "y\xcc\xa6\xbb")[0]', 'import struct').timeit() 0.36242198944091797 >>> Timer("int('y\xcc\xa6\xbb'.encode('hex'), 16)").timeit() 1.1432669162750244   My hacky method:  >>> Timer("sum(ord(c) << (i * 8) for i, c in enumerate('y\xcc\xa6\xbb'[::-1]))").timeit() 2.8819329738616943   FURTHER UPDATE:  Someone asked in comments what's the problem with importing another module. Well, importing a module isn't necessarily cheap, take a look:  >>> Timer("""import struct\nstruct.unpack(">L", "y\xcc\xa6\xbb")[0]""").timeit() 0.98822188377380371   Including the cost of importing the module negates almost all of the advantage that this method has. I believe that this will only include the expense of importing it once for the entire benchmark run; look what happens when I force it to reload every time:  >>> Timer("""reload(struct)\nstruct.unpack(">L", "y\xcc\xa6\xbb")[0]""", 'import struct').timeit() 68.474128007888794   Needless to say, if you're doing a lot of executions of this method per one import than this becomes proportionally less of an issue. It's also probably i/o cost rather than cpu so it may depend on the capacity and load characteristics of the particular machine.


the example could be seen from the new google calendar   it was white font on a saturated color box (colorful, very 'rich' in colors', 'bright', or im not sure what's the technical way of describing this)   what are the benefits and harms of this because it appear to be very very hard to see the font when this is done  p.s. hello this is not duplicate cos 'bright' colors arent dark, and also there's no answer to google calendar, so it shoulnt be 'duplicate'

For a very technical site documenting code, sharing code snippets, and documentation, I have been told that using dark fonts on light backgrounds is recommended for people being able to read the information clearly as possible.  While, for my eyes and designing skills, dark backgrounds and light text works way better for me. A few clients have said that that does not work at all for the type of site which I have created.   Which would work better for a technical site: dark backgrounds with light colour fonts or light backgrounds with dark fonts?


Technically proficient with Microsoft Office Suite? Or Technically proficient in Microsoft Office Suite?  Please help me to understand if the sentence is correct?  Thank You!

Which preposition is correct in the phrase "proficient in/at/with English"?


im new to Java and Spring. Im doing my first app with Spring MVC Begginers Guide and i have problem with my "category" field validator. It doesnt work correctly.. Tbh It doesn't work at all.  category.java  @Target( { METHOD, FIELD, ANNOTATION_TYPE }) @Retention(RUNTIME) @Constraint(validatedBy = CategoryValidator.class) @Documented public @interface Category {     String message() default "{com.packt.webstore.validator.Category.message}";     Class<?>[] groups() default {};     public abstract Class<? extends Payload>[] payload() default {};     String[] allowedCategories() default {"Laptop","Tablet","Smartfon"}; }   CategoryValidator.java  public class CategoryValidator implements ConstraintValidator<Category, String> { String[] allowedCategories; public void initialize( Category constraintAnnotation ) {     this.allowedCategories = constraintAnnotation.allowedCategories(); } public boolean isValid( String value, ConstraintValidatorContext context ) {     for( String category : allowedCategories ) {         if( value == category ) {             return false;         }     }     return true; }   The problem is that everything i type in my "category" field it return that its not correct category :/  I was googling about my problem but didnt find anything :( Can somebody explain me what am I doing wrong :)? Thanks!

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


i am using a library called mathjs When i try to add two numbers as follows   var n1 = 271.837500;         var n2 = 2.887500;         var n3 = math.add("271.837500", "2.887500");   the value of the variable n3 is 274.72499999999997 instead of 274.725000 Can any one explain me why i am getting this value?

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


I'm making a mario clone, and I have been working on the collision but I can never seem to get it right. I started out with "true/false" collision, aligning the player at it's last position, and as can guess, the results were barely ok. The problem was in the alignment and in the direction of movement. I then converted my collision function to return the rectangle area of intersection as shown in the top left corner: (Yellow rectangle)  I now have a bunch of other problems which I think are more acceptable to solve. I'm unsure of what to do with the data I get from the function now. My current logic is this: // Update Gravity // Update Movement // Check for collision // Intersect2 applies offset to a existing rectangle, and returns true or false. if(Intersect2(*level, *camera)) // Check collision against level, but only against tiles in camera view. {     // Correct Y Movement     if (offset.height >= 16) sprite.move(0, offset.height); // 16 is half a tile size     else      {         sprite.move(0, -offset.height);         inAir = false;     }     velocity.y = 0;          // We corrected Y, are we still intersecting? then correct X as well     if(Intersect2(*level, *camera))      {         if (offset.width >= 16) sprite.move(offset.width, 0); // 16 is half a tile size         else sprite.move(0, -offset.height);         velocity.x = 0;     }     // Reset the offset rectangle     offset.height = 0;     offset.top = 0;     offset.left = 0;     offset.width = 0;  }  How can I apply the offset in a correct way? Side note: I have stuttering problems while on ground, as my gravity is always "on" so that I can fall down when walking off an elevated block.

I am working on a game in JavaScript and my current implementation of collision uses the shortest distance to push the intersecting object away, which isn't always correct. I've made this diagram of the ideal collision. The red box represents the starting position, the green box represents the proper position and the black box represents the static object it is colliding against. The blue arrow is the velocity vector. With my current implementation, the object would be placed in its final position and pushed out (and in this case it would be pushed left)    How can I fix this?


While trying to generalise a mechanics exercise with a friend, we came up with this question, in an attempt to understand wether sine curves with irrational period defined inside an annulus will end up 'filling up' the space in the annulus.   Mathematically, let $x \in \mathbb{R} \setminus \mathbb{Q}$:  Is $S_x=\{\mathrm{frac}(n x): n \in \mathbb{N}\}$  dense in $[0,1] \subset\mathbb{R}$?  This is equivalent to asking wether sequences of fractional parts of multiplies of one fixed irrational number can approximate every number in $[0,1]$.   My intuition says this may be true, but I see no reason why there shouldn't be some 'holes' in $S$. If that's the case, which kind of properties of $x$ determine the how $S_x$ is filled up?

Say you picked your favorite irrational number $q$ and looking at $S = \{nq: n\in \mathbb{Z} \}$ in $\mathbb{R}$, you chopped off everything but the decimal of $nq$, leaving you with a number in $[0,1]$.  Is this new set dense in $[0,1]$? If so, why? (Basically looking at the $\mathbb{Z}$-orbit of a fixed irrational number in $\mathbb{R}/\mathbb{Z}$ where we mean the quotient by the group action of $\mathbb{Z}$.)  Thanks!


I have ~700 votes, and am sure that a lot more than 25% are on questions.  What could be the problem?

Formerly List of all badges with full descriptions.  What are badge name's requirements? Why didn't I get badge name ? Which badges can I earn multiple times?    Jump to:                    Note: Some badges are awarded based on score. The term score means the total number of upvotes minus the total number of downvotes.  Any badge with a *** next to it is one of 20 badges that count towards the  displayed on a moderator candidate in an election. The candidate score is a total of 40 points: the first 20 are awarded based on the user's rep divided by 1000 and rounded down; the second 20 represents the total number of unique badges earned of the 20 that count. Note that if the same badge is earned multiple times, it will only count once towards the candidate score.  Any badge with a "(retired)" next to it is no longer awarded, but is retained by users who previously earned them. See  for more info on what it means for a badge to be retired.       Visit the  of the  on any site to see a complete list of badges that you can filter by earned, unearned, or type.


I need to change Label text in registration form, especially "Email" label. I want to add asterisk or just add text "required field" How can I do that? Please advice...

Is there an easy way to add a required symbol like '*' after the html <label> text content in the default user registration form?  I'd like the Username and E-mail labels to display: Username * and Email *  I've tried using CSS, as in:  #registerform p label::after {     content:" *";     color: red; }  But the asterisk appears under the text field, not beside the text.  I checked the Codex but couldn't find a WP filter, so does this mean I need to create an entirely custom registration form?


I downloaded fifteen mods on my PS4 and was leaving the secret Thieves' Guild entrance when she disappeared. I already completed Dawnguard and also have Dragonborn and Hearthfire. I don't want to start over because some of the mods would be ineffective. Also, the other loads were auto-deleted. I also waited 24 hours and went to Fort Dawnguard and Volkihar Castle just in case, but she wasn't there. Do you have any suggestions/advice?

I am doing the Dawnguard questline and I was getting the last elder scroll from septimus sigmus.   I told her to wait while I was doing stuff with the lexicon as she kept getting in my way.  She did however follow me out when we were finished we then went to the dawnguard to talk to the moth priest and we now have to find a moth priests knife.   I went to Riverwood to feed and I'm not sure if she went there with me or not but I have not been able to find her at all throughout the rest of my game play. Nothing on google has helped me it's like she has just vanished from the game even though I still need her for quests.


I am a non-EU national, with a valid Titre de Sejour in France (which is a long-term residency visa).   My passport has expired and it takes time to update it. Can I travel (for one week) within the Schengen area with Titre de Sejour only, or perhaps together with an expired passport?  In this , it's stated that both a valid passport and a visa/residency-card is needed.

I am currently located in the Netherlands and have lived here for 4 years. I have a working visa for the Netherlands and would like to go on vacation to another country in Europe. I however do currently not have my passport as i sent it to an embassy for a visa application. Will I still be able to travel inside of Europe without a passport if I have my residency ID?  I have a resident permit, not a true Dutch ID. And I own a passport that is currently in transit.  I have called with the KLM and the service employee's conclusion was that I do need to carry my passport with me when i am going to fly, so it seems all I can do is wait and hope my passport is returned to me in the next few days as the amsterdam US consulate (who currently holds my passport) is incredibly difficult to contact for urgent matters.


A friend of mine (an I.T. guy) gave me this tricky probability problem, that I couldn't solve.  $n$ persons go to a cinema that has $n$ seats, and everyone of them has an assigned position written on the ticket.  The first person $p_1$ commits an error and chooses the wrong seat.  Then $p_2,\ldots,p_n$ arrive (in order) and they choose their seat according to the following rule:  "If the assigned seat is free, go there. Otherwise, choose a random seat among the free ones."  What is the probability for the last person $p_n$ to sit in his assigned seat?

This is a neat little problem that I was discussing today with my lab group out at lunch. Not particularly difficult but interesting implications nonetheless  Imagine there are a 100 people in line to board a plane that seats 100. The first person in line realizes he lost his boarding pass so when he boards he decides to take a random seat instead. Every person that boards the plane after him will either take their "proper" seat, or if that seat is taken, a random seat instead.  Question: What is the probability that the last person that boards will end up in his/her proper seat.  Moreover, and this is the part I'm still pondering about. Can you think of a physical system that would follow this combinatorial statistics? Maybe a spin wave function in a crystal etc...


prove that: $$8\mid (n-1)n(n+1)(n+2)$$  I tried to simplify this expression but had no luck.

Prove that:   $$24\mid n^4 + 2n^3 - n^2 - 2n, \quad \forall n\in \mathbb{Z}^+$$   I tried to prove it, but had no luck.


(I keep re-reading that question title and thinking about how ridiculous it must look, but I assure you that is the best description of the problem, and I have an actual application where this is the best structure. I swear I'm not crazy.)  Consider the following. Each block is a separate file:  package myPackage;  public class A {      public int i;      public A(int i) {         this.i = i;     }      public class B {      } }     package myPackage;  import myPackage.A.B;  public class Main {      public static void main(String[] args) {         class C extends B {             public C(A enclosingInstance) {                 enclosingInstance.super();             }              public void show() {                 System.out.println(A.this.i);             }         }         A myA = new A(2);         C myC = new C(myA);         myC.show();     } }     Note that the enclosingInstance business is to solve a problem involving intermediate constructor invocations. See .  I would expect the output to be "2". But instead, I have a compile error on System.out.println(A.this.i);:     No enclosing instance of the type A is accessible in scope   I think the programmatic concept I'm trying to solve is sound: Create a new type of B inside main to give to A that uses things from A that types of B can access.  So what am I doing wrong, or why isn't this possible in java?  EDIT/UPDATE: Note that the same error appears when the code in main is moved to a non-static method. That is to say, I tried moving everything inside of static void main to a new, non-static method of class Main called go(). Then I changed static void main to the single line new Main().go();. The error is in the same spot. So it doesn't seem to be an issue of class C being defined in a static context.

What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these?


So, I've reached the end of my "quests" and stuff on the planet, but because the game isn't "fully downloaded" it's not letting me leave. It's been stuck at 99.95% for downloading for about two or three weeks now, and it's kind of pissing me off because I would like to move on in my gameplay.  How can I make the game download the rest of the update?

I've been playing SW:TOR for about a week now, and the game has been completing the download in the background.   It stopped at 99.18% downloaded three days ago. Now, I'm level ten and finished on my planet, but I can't get off the planet because the game "is not fully downloaded". How do I get my computer to finish that last percent of download?


I have few line that listing to this script  $("a.remove").click(function(){     var id = $(this).attr('id')     var user = $(this).attr('value')     $.ajax({         success : function(){             var url = "includes/action.php?page=access&action=remove";             var popupmessage = "Error";             $.post(url, { id: id },                 function(data){                     return true;             });         }     }); });   but when i add new line via jQuery it doesn't work until refreshing the page  $("").insertAfter('#accesstable tr:last');   any idea how to fix it ?  Edit: Working code  $('a.remove').live('click', function(){     var id = $(this).attr('id')     var user = $(this).attr('value')     $.ajax({         success : function(){             var url = "includes/action.php?page=access&action=remove";             var popupmessage = "Error";             $.post(url, { id: id },                 function(data){                     return true;             });         }     }); });

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.


Background  We are proving that two free groups on sets $S_1,S_2$ are isomorphic iff the sets have the same cardinality. If they are finite, it's easy to show, by the freeness of the groups, that $2^{|S_1|}=2^{|S_2|}$, and thus the cardinalities are the same. Otherwise the power sets are in bijection, which is shown in the same way.  The problem is that in the infinite case, I'm not sure how to prove that bijection of power sets implies bijection of sets. I tried by contradiction, but only got stuck with one p.s. being in bijection with a proper subset of the other and not being able to rule out that this proper subset be in bijection with the whole p.s.  Question  Is it true that if the power sets of two sets are in bijection, then the two sets also are? If so, how do I prove it? Otherwise, can you provide a  counterexample? And if this does not hold how do I complete the proof in the background section?

Is it generally true that if $|P(A)|=|P(B)|$ then $|A|=|B|$?  Why? Thanks.


I just took a picture of myself using my iPhone, but I can't upload it using this application. I'd like this to be possible very much though, is there any room for consideration?  PS: willing to make a pun like 'seeing the bigger picture of this feature.'

The iOS-app should provide (at least) the same features as the site and the ability to edit your profile is not so unimportant.  In my opinion, the user should be able to change the every single info-field in his profile (including, but not limited to nickname, description, profile picture) by pressing an "Edit" button which should be located somewhere on his or her profile view.


I am curious why Stack Network can't count all websites' achievements together. If someone has many stack websites, it will not show all points of a contributor. It sounds that it's a waste of time to level up for other insignificant websites. The question differs from . In my opinion, it's strange to bound the site together on the menu but counts achievement separately.

I use the Stack Exchange sites very often to find solutions to problems and help me with decision-making.  In some sites I have asked question and received answers, and I have more than 15 reputation. On Stack Overflow I have always found answers to my questions and never needed to post a question (avoiding duplicate questions). However, I would like to vote for the answers that helped me but I do not have the ability to do that, due to low reputation.  Posting a question or answering an answer on each site seems like the only way to get enough reputation.  Since I have no input to give in these areas unless they will be counted as duplications, many answers that I have already used are missing my vote.  I suggest to take into account all of the reputations from all Stack Exchange sites for voting, or thinking about a different way to allow votes.


I'm having trouble importing DXF / DWG into Altium.  I followed File-->Import-->selected my dxf,dwg-->config-->Information show Done!!-->and nothing shows up on my mechanical layer.  I'm using Altium Version 15.1  Any tips or workarounds ?  THK

I'm having trouble importing DXF / DWG into Altium.    I followed the procedure outlined in the   File-->Import (selected my dxf) and nothing shows up on my mechanical layer. I've tried multiple DXF files that I have used in the past.   I'm using Altium Version 13.3.4 (Build 28908)   Any tips or workarounds ?


Question marked as duplicate, as is nearly every other question about blacklisting and whitelisting. Some of these questions are different because: 1) XP has a different firewall than Vista/Win7/Win8 2) Some questions are about blacklisting, others whitelisting. 3) Some whitelisting questions are by domain names, others by application. 4) Some questions are focusing on easily switching profiles, while others are seeking permanence. The main answer that has been provided from the linked duplicates is how to configure the Windows firewall. This does not completely help, and even where it does, is not very easy. My answer was to use tinywall, which seems to be working. Might i suggest that these questions are not so easily marked as duplicates, because the nuances of each can make a huge difference in whether previous answers are applicable.  A friend has a laptop running Windows 8.1 which is using an Internet connect from T-Mobile's Rocket (USB/4G) which comes with 200 MB/month for life. The purpose of the Internet connection is to use Fast Forward for his son, which should use about 50MB/month for our usage of it. So, the 200MB should be enough, possibly for virus definitions as well. His house has no other Internet connection, and no wireless networks are strong enough to be used. Periodically, if required, i can bring his laptop to my apartment and get him all pending updates (as i am doing right now).  A such, i want to block all traffic except for Fast Forward and Windows Defender definition updates. Will the Windows Firewall do that? If so, how?  --  For the first week or two, he also wants to get healthcare under the new law. So, browsing needs to be available at first. Extra Internet bandwidth will be purchased as required for this endeavor, but i'd like to help him keep that to a minimum for him as well.  How would we best go about this?

Is it possible to use Windows Firewall to block specific web sites for all browsers?


I ask this question in response to a discussion on . If $f(x)=p(x)/q(x)$ is a one-variable real rational function, then for each $r\in \mathbb{R},$ $f(x)=r$ has at most $d=\max\{\deg(p),\deg(q)\}$ solutions; this is due to the Fundamental Theorem of Algebra. So, for instance, if we had a rational function of one variable of the form quadratic/quadratic that took the same value at four points, we could conclude it is constant. Does a similar result hold for multivariable functions? If so, when; if not, does a partial result hold?

We already know the following theorem by d'Alembert and Gauss, often called fundamental theorem of algebra.  Theorem Let $P$ be in $\mathbb C[X]$ of degree $1$ or greater. There exists $\alpha\in \mathbb C$ such that $P(\alpha)=0$.  Can we give the following generalisation for polynomials with several variables?  Generalisation Let $n$ be in $\mathbb N^*$ and $P$ be in $\mathbb C[X_1,\ldots,X_n]$ of degree $1$ or greater. There exists $\alpha\in \mathbb C^n$ such that $P(\alpha)=0$.  Any references, hints or solutions would be greatly appreciated.


LibreOffice 6.0 has been released. How can I install LibreOffice 6 in Ubuntu? What is the official PPA?

LibreOffice is seeing some dramatic improvements each version and subversion that goes out.   I would like to have always the latest version of LibreOffice on my machine(s). I know of the PPA that exists but is it recommended to use it with 12.04 for daily use? What are the pro and cons of using the PPA? Will it break my system/Libreoffice installation?  Does libreoffice get eventually also upgraded in the Ubuntu repositories or does this upgrade happen only with new releases? Who manages the upgrades of libreoffice in Ubuntu and in the PPA?


According to FXCop, List should not be exposed in an API object model.  Why is this considered bad practice?

Can anyone explain to me why I would want to use IList over List in C#?  Related question:


Hi I am creating some dynamic  elements here   function loadApiData(){ var url, jqxhr, url2, jqxhr2, status; for (i = 0; i < 11; i++) {     url2 = document.URL + 'status/' + i;     jqxhr2 = $.getJSON(url2, function(data) {         console.log('API response received');         //console.log(url2);         console.log(data);         status = data['status'];         //console.log(status);         if (status == false) {             //$('#false').append('
' + data['phone'] + ' phone Status: ' + status + '
');             $('#false').append('
' + data['phone'] + ' phone Status: <input type="button" id="' + data['phone'] + 'off" value="' + status + '" />
');         } else {             $('#true').append('
' + data['phone'] + ' phone Status: ' + status + '
');         }     }); }  };   However when I then try loading them later   function loadWindowSystem() {  $('#Nimoff').click(function() {     alert('hi'); }); };   I find that it doesn't actually register the click event.   My document.ready() looks like this.   $(document).ready(function(){ loadApiData(); loadWindowSystem(); });   Any help would be greatly appreciated.  Thanks  Resolved by using   $( document ).on( 'click', '#Nimoff', function () { // you code });

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 an Indian passport and a valid US visa. I have two stopovers in Frankfurt and Munich while going to India with Lufthansa. I have a change of flight in both places. Do I need an airport transit visa?

I have Indian passport and USA H1 valid visa, will be travelling US and my itinerary is Mumbai – Munich – Frankfurt – San Francisco. This route has two stops in Germany, Munich – Frankfurt is German domestic flight. I am not sure if I would need a Schengen or Transit Visa. I was going through few German and Indian consulate visa website but I am not able to get the correct info, specially below two statements are confusing. Could you please help me with this?    In these five airports in Germany you can stay at the International Transit Area without a visa: 1.  Cologne/Bonn 2.  Düsseldorf 3.  Frankfurt/Main 4.  Hamburg  5.  Munich  Airport transit privilege does not apply in the following cases and you will need to get a visitor visa if: You are transiting through two or more airports in the Schengen Countries


I'm new to Java but not new to programming. I ran the following code in Eclipse:  int[] intArray = new int[5]; System.out.println(intArray);   and received the following output:  [I@17f7be7b   I'm sure StackOverflow already contains the correct way to create an array in Java. What I'd like to know is: what did I do?    Edit: Sorry... The link above my post isn't a duplicate question, and it doesn't answer my question. TylerAndFriends' link is closer, but I was hoping for an explanation of exactly what I printed. Tyler's linked thread says "the default method is to display the object's class name representation, then "@" followed by its hashcode". Can someone elaborate?

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


The Blacks were shown to be very anti-Muggle. Their house has anti-Muggle spells placed on it. Yet, their house is placed in a Muggle neighborhood, with a Muggle number.  Why?

Why did Sirius Black's family live among Muggles?  The Black family were generational purebloods -- one of the "official" pureblood families -- and canon has demonstrated that they were vehemently anti-Muggle, aside from Sirius (One might argue Regulus as well, after his change of heart.). Yet they lived among Muggles, seemingly by choice. It's certainly possible number twelve Grimmauld Place was family property received by inheritance, but the Black family surely predates the construction of some row houses in a shabby part of London. I would think?  Why did the Black family choose to remain there? Why didn't they move?  Is there anything in canon that addresses this? Does Sirius explain why his family's home is in a Muggle neighborhood at any point in the series?     They were standing outside number eleven; he looked to the left and saw number ten; to the right, however, was number thirteen.   ‘But where’s –?’   ‘Think about what you’ve just memorised,’ said Lupin quietly. Harry thought, and no sooner had he reached the part about number twelve, Grimmauld Place, than a battered door emerged out of nowhere between numbers eleven and thirteen, followed swiftly by dirty walls and grimy windows. It was as though an extra house had inflated, pushing those on either side out of its way. Harry gaped at it. The stereo in number eleven thudded on. Apparently the Muggles inside hadn’t felt anything.   Order of the Phoenix - page 58 - Bloomsbury - chapter 4, Number Twelve Grimmauld Place


I am new to C++, coming from C#. Here is the code :   void function(int n) {     double* array = new double[n];     //some work that can return or throw an exception    //...     delete[] array;    return; }   I know there is no C# using equivalent in C++.   Is there a simple and elegant way to ensure that memory will be released what ever happens ?

Does C++ support '' blocks?  What is the ?  What is the difference between C++'s RAII idiom and ?


What is the purpose of the optional argument of \linebreak? What is the difference between \linebreak and \linebreak[1]?  MWE:  \documentclass{article}  \begin{document}  test\linebreak test   test\linebreak[1] test  \end{document}

Where can I find documentation on how to use the \nolinebreak command?  The  at  never makes mention of \nolinebreak  The  states that \nolinebreak is implemented by multiplying its input parameter penalty by (-1) and passing the result into \nopagebreak.       I haven't found documentation on how to use the command.


I want to print "Hello - World" by using two char pointers but I have a "Segmentation fault (core dumped)" problem.   #include <stdlib.h> #include <string.h> #include <stdio.h> #define Hyphen " - " int main() {   char* x="Hello";   char* y="'World'";   strcat(x, Hyphen);   strcat(x, y);   printf("%s",x);   return 0; }

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.


Has anyone tried oval chainrings? Are they worth the time and money? Any brands worth considering? I'm trying to gain any advantage I can get

I have seen competitive (amateur) cyclists with oval chainrings (front). What is the deal? Are they just for showing off, or is there a practical gain from it (different force transfer).


I have an ordinal score ranging from ( 1 to 5 ) called "Score"   I have another binary variable Human Response (Yes or No ) called "h_score"  I don't think i can do correlation study in this case as the h_score isn't numeric or ordinal and hence correlation doesn't make sense.   How do i analyze if there is difference in distribution of score across h_score ? Can I use chi square test ?

I'm struggling with my lab report. I have a questionnaire which contains Likert responses (1-7) as well as questions that require only yes or no answers. I want to see if there is a correlation between higher scores on the likert scale and responses to the binary answers to the other questions.   Specifically - the likert response is about anxiety levels. The binary (yes/no) answer is about negative consequences due to alcohol use. I want to just run the one ordinal likert item with all the negative consequence responses to see if there is a relationship. Can anyone help me?     Thanks so much for the fast comments. It definitely assures me that Spearman's Rho can be used but my main problem is the fact that i am mixing binary and ordinal variables together in the one correlation matrix.  I have one ordinal variable (anxiety - 1-7 on likert scale) crossed with 13 dichotomous (0 or 1 representing yes or no) to answers ("have you ever been hospitalised due to your alcohol use?). I get statistically significant answers (<.05 and < .01 but the Correlation coefficients are tiny (i.e o.2) at best.   the hospitalisation is the DV an the anxiety levels the IV.   I just think i'm doing something wrong here. should i collapse the 13 binary variables in to one some how?   i can't see how SPSS will recognise the values between 1-7 when correlating with binary answers. i keep thinking it will just read that there is something in that box (ordinal) but not recognise the value (i.e 1-7) . but people keep saying that SPSS does in fact recognise this difference and account for it.


When I try creating a new face at a certain place, it seems to be back to front or something for some reason. When I bevel the edge the vertices are also in the wrong places. Here's a few images to show what I mean: Before I add the new face:  When I add the face:  When I add another face adjacent:  When I try to bevel:

While rendering a mesh with smooth shading on, I get a dark region/shadow on certain faces. The effect is more evident when smooth shading is applied to a mesh containing ngons, with the ngons turning black when rendered.   The blackening effect is visible in the viewport too.  How can I solve this problem?


Is there a way I can lock my door in vanilla Minecraft? I have tried naming a tripwire hook key, but it didn't work youtube told me to do that.

How can I make a safe/vault or something to lock my door that is very easy (as I am not that advanced with redstone) to keep people out of my house? Without mods?