Let $(X,d)$ a metric space such that $\exists A\subseteq X$  uncountable and $\exists \epsilon\gt0$ such that $\forall x,y \in A,x\neq y\Rightarrow d(x,y)\gt\epsilon$. Prove that $X$ is not a separable space and and use this result to show that $(\ell^\infty,d_\infty)$ is not separable.  There is a result that says that in a separable metric space, every uncountable subset contains a point of accumulation. There is a result that says that in a separable metric space, every uncountable subset contains a point of accumulation. I started considering the result, which did not lead to anything. Then, by contradiction, I wanted to prove that $X$ is separable. In order to use that, I could see if $X$ has a countable base or a cover of open sets of $X$ has a countable subcover.

I have to prove that $\ell^{\infty}(\mathbb N)$ is not separable.  My attempt  Consider a SUBSET $V$ of $\ell^{\infty}(\mathbb N)$ consisting of bounded sequences that have only $0$, $1$ entries, e.g. $(0,1,1,0,0,0,0,1,0,0,\dots)$  Now assume that this SUBSET is uncountable.  If we take a radius $r=1/4$ then balls with origins that are elements of $V$ would be disjoint and because any base of  $\ell^{\infty}(\mathbb N)$ must contain a subset of each element of the set of these balls, base of  $\ell^{\infty}(\mathbb N)$ can't be countable so it doesnt satisfy the second axiom fo countability and thus is not separable (since  $\ell^{\infty}(\mathbb N)$ is a metric space).  Could someone check this? And I still need to prove that $V$ is uncountable...


The ggplot2 package in R includes a dataset called diamonds. The dataset can be accessed by loading ggplot2 like this:  library(ggplot2)   I'm using the boot package to calculate a 95% confidence interval for the mean of the table variable. The table variable has 53,940 observations, and therefore when I tried to use 10,000 bootstrap replicates R crashed:  library(boot)  boot_diamonds_10000 <- boot(diamonds,function(data,indices) mean(data[indices,]$table), R=10000)   I then tried using 1000, 100 and 10 bootstrap replicates like as below. The 1000 and 100 replicates are still slow function calls, but 10 replicates is faster:  boot_diamonds_1000 <- boot(diamonds,function(data,indices) mean(data[indices,]$table), R=1000)  boot_diamonds_100 <- boot(diamonds,function(data,indices) mean(data[indices,]$table), R=100)  boot_diamonds_10 <- boot(diamonds,function(data,indices) mean(data[indices,]$table), R=10)   These all give pretty much the same 95% confidence intervals:  quantile(boot_diamonds_1000$t, c(0.025,0.975))  # 2.5%    97.5%  # 57.43890 57.47682  quantile(boot_diamonds_100$t, c(0.025,0.975))  # 2.5%    97.5%  # 57.43638 57.47438   quantile(boot_diamonds_10$t, c(0.025,0.975))  # 2.5%    97.5%  # 57.44636 57.46841    To avoid crashing R or waiting for slow functions calls, is it reasonable to use 10 bootstrap replicates when the sample size (53,940) is so high?

I wonder if someone knows any general rules of thumb regarding the number of bootstrap samples one should use, based on characteristics of the data (number of observations, etc.) and/or the variables included?


Virtualbox only shows 32-bit VMs even when i use 64-bit CPU  I use 64-bit CPU and i turned virtualisation on. I tried enabling HyperV on and off a couple of times, but it didn't work(HyperV doesn't work either). Everything works fine on Linux.

When I start VirtualBox, I only have 32 bit operating systems available. After some research I followed the steps on  but to no avail. My host OS is 64 bit, Intel Virtualization Technology and VT-d are both enabled in the BIOS, and Hyper-V platform is disabled in the Windows Feature list, yet I still only am presented 32 bit operating systems.  I find these    and they seem to solve the problem for everyone, but not for me.   I also tried  the installation without luck. How can I fix this to run a 64 bit Linux OS in VB?  EDIT I also have the latest version of BIOS.  Edit: This question is not a duplicate of  as I state that the solution to that question did not solve this problem.


If it is possible to open and visualize a KML Network Link in QGIS, then what are the steps involved? KML Network Links are described at  and at :  In the most generic sense, a KML file with a network link acts as a gateway into the content on your server. Your users download your KML file just once, but they will always see the most updated content, even if you updated it after they download your KML.  A KML file with a network link can be embedded within a KMZ file.

I know I can add KML files once I have unzipped the KMZ files, but is there a way to open KMZ files directly?   When I try to open a kmz file on QGIS 1.8.0 on Windows XP, through the all files filter, it does not accept it as a valid format.   Am I doing something wrong?   Does this all depend on OGR support?


When speaking about electrical charges, it seems every particle either has a charge $+1$ or $-1$, in units of the electron charge. Therefore, we have a fundamental charge.  But what about mass? Is there any kind of such mass that every other mass can be seen a sum of those basic masses?

Why do we have an elementary charge $e$ in physics but no elementary mass? Is an elementary mass ruled out by experiment or is an elementary mass forbidden by some theoretical reason?


New Ubuntu 12.04 LTS user here.  I have downloaded Google Earth, it shows as its downloaded but says it must be operated from a terminal.  Could someone please explain what terminal means in that context. Thanks, Steve

What is a terminal? How do I open a terminal window? How do I use the terminal?


I am studying in 10 th grade. In statistics chapter they gave formulas of mean,mode,median for grouped data. I could derive formula for mean easily but I can't for others. My textbook also didn't gave derivation, they blindly put them in textbooks and make students to mug them. I am curious to know how these formulas came.

A formula to calculate the mode for grouped data's is given in my text book: Mode = $l + \dfrac{(f_1 - f_0)h}{2f_1 - f_0 - f_2} $ Where, $l = $ lower limit of the modal class, $h = $ size of the class interval, $f_1 = $  frequency of the modal class, $f_0 = $ frequency of the class preceding the modal class, $f_2 =$ frequency of the class succeeding the modal class. Can you please explain the derivation of this formula, as it is not given in my T.B. Thanks .


From what i know,  is assigning as hashCode the memory address of the object.   And, obj1 = obj2 returns true iff the obj1 is obj2, i.e., they're sitting at the same memory location.   However, the following code executes the "else" part-- not the "then" part of the if-stat which is what i expect:  String h1 = "heya";  String h2 = new String ("heya"); System.out.println("hashCodes "+h1.hashCode()+" "+h2.hashCode());   if (h1 == h2)          System.out.println("yeah - the same ");   else System.out.println("nope-- difft objects ");     What am i missing here?  TIA.

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?


Let $A$ be a real $m \times n$ matrix. Show that the matrix $M$ defined as $$M = \alpha^2 I_m + A A^T$$ is nonsingular, where $\alpha$ is a nonzero real number.

The question is quite simple: for a $N \times p$ matrix $\mathbf{X}$ with real entries, when is $\mathbf{X}^{T}\mathbf{X}+\lambda\mathbf{I}$ invertible (where $\mathbf{I}$ is the $p \times p$ identity matrix and $\lambda > 0$)?  This comes up in ridge regression. In Elements of Statistical Learning (Hastie et al.),      [The equation] adds a positive constant to the diagonal of $\mathbf{X}^{T}\mathbf{X}$ before inversion. This makes the problem nonsingular, even if $\mathbf{X}^{T}\mathbf{X}$ is not of full rank.   I know that $\mathbf{X}^{T}\mathbf{X}$ is invertible if and only if it is of full rank if and only if $\mathbf{X}$ is of full column rank. The explanation is quite intuitive, but how do I prove it?


The thesis latex template of my university has \usepackage{amssymb} Can someone please explain what that package does?

In my view, any document with a substantial amount of mathematics should load the packages from AMS-TeX. Hence, most of my document's preambles contain  \usepackage{amsmath, amsthm, amssymb, amsfonts}   (I could add to that the non-AMS mathtools, etc.). What do each of those packages do? Do I really need to list all of them, or do some of them load others? In particular, does any package load all of them, so that I can simply type  \usepackage{ams-everything}   shorter than the current list?


Let $R$ be a ring such that   $$ x^2-x \in C(R) \quad \forall x \in R,$$   where $C(R)$ is the center of $R$. Prove that $R$ is commutative.   I cannot find any route to proceed. How can I start? Please give hints instead of full solution.

If $x^{2}-x\in Z(R)$ for all $x\in R$, then $R$ is commutative.  I need to proof this theorem and I have something like this below. However, I do not know how to continue this proof.   $(x+y)^{2}-(x+y)=x^{2}+xy+yx+y^{2}-x-y=(x^{2}-x)+(y^{2}-y)+xy+yx\in Z(R)$  so $xy+yx\in Z(R)$


Like the title suggests, I am wondering if there is any way to transfer my beloved Pokemon from the Gen 1/2 games to the VC games so I can get them to Bank, Home, and eventually Let's Go, Sw/Sh, and Bd/Sp.  However, I can't find a thing on the internet about this.  Maybe I'm just an idiot and not looking hard enough, but I really want to know how since I don't see any link cables that adapt GB(C) to 3DS.

I have a Game Boy Advance SP and Pokemon Red GEN 1, and I'm curious if it is possible for me to trade a Pokemon from Red to the Virtual Console release of Pokemon Gold on the 3DS


I need to calculate the average score of a list of userId.  I have a table "user_place_score" (user_id / place_id/ score).  Sometimes I do not have the score for a user_id so I need to fetch a "default" score in a the "default_place_score" table (place_id / score).  Is is possible in PostreSQL to do this in one query ? For a a given list of users and one place_id select all their score in the user_place_score and if now row found take the score found if the default_place_score table ?  Basically I want to avoid doing this kind of stuff:  for (Integer userId : userIds) {   score = (query to fetch the score for this userId)   if (score == null)     defaultScore = (query to fetch the default score for this PlaceId)    total = total + defaultScore }  //return the average return total/numberOfUser   Thank you!

I need to calculate the average score of a list of userId.  I have a table user_place_score:  (user_id, place_id, score)   Sometimes I do not have the score (no row for (user_id,place_id) in the table) so I need to fetch a "default" score from the table default_place_score:  (place_id, score)   Is is possible in PostgreSQL to do this in one query? For a given list of users and one place_id, select all their scores in the user_place_score and if no row is found then take the score found if the default_place_score table?  Basically I want to avoid doing this kind of stuff:  for (Integer userId : userIds) {   score = (query to fetch the score for this userId)   if (score == null)     defaultScore = (query to fetch the default score for this PlaceId)    total = total + defaultScore }  //return the average return total/numberOfUser


The  is an excitation of the Higgs field and is very massive and short lived. It also interacts with the Higgs field and thus is able to experience mass.   Why does it decay if it is supposed to be an elementary particle according to the standard model?

According to , a muon decays into one electron and two neutrinos.    According to , elementary particles or fundamental particles are particles "whose substructure is unknown, thus it is unknown whether it is composed of other particles."  I have also seen somewhere that it is a particle that cannot be reduced into other constituent particles.  While perhaps not a sure thing, seems like the decay indicates that the muon may be just a composite particle, perhaps consisting of one electron and two neutrinos?   Based on this, why does the muon fit with the above definition of an elementary or fundamental particle?    I realize there are much more complicated, historical reasons as to why it was included in the Standard Model, but this question is just related so how it fits (or doesn't fit) the stated definition above.  It seems to me that we really can only get solid evidence of elementary vs. composite when we smash the particles together and see what comes out and compare that to all the masses, energies and momentum before and after?  Until we do that with muons, how can we know with much certainty?  And perhaps we'll have a better answer with a Muon collider:       To that point, seems that electrons may not be fundamental after all:


How can I prove that if $f$ is continuous on $[0, 1]$ such that for every $x \in [0, 1]$ we have that $\int_{0}^{x} f(t) \,dt = \int_{x}^{1} f(t) \,dt$, then $f(x)=0$ for every $x$.

If $f:[0,1]\to\mathbb R$ is continuous and $\int_0^x f(t)dt = ∫_x^1f(t)dt$ then prove that $f(x)=0$.  I suppose that $f(x)$ isn't zero, set $g(x)= \int_y^xf(t)dt$ with $y\in[0,1]$ and use Bolzano but I don't know if it's right.


I need a regex that would replace something like this but leave the file name.  /folder1/folder2/folder3/anything/somefile.html  Also could someone show me how to implement this with replace method? Replacing the entire path match to empty string and again leaving the file and which would be anything.  Thanks in advance.

Is there a way that I can get the last value (based on the '\' symbol) from a full path?  Example:  C:\Documents and Settings\img\recycled log.jpg  With this case, I just want to get recycled log.jpg from the full path in JavaScript.


I am working with a data set of the mass of plastic found at various sites. At most sites, we found no plastic and so the data is zero-inflated (see histogram below). I want to model the data using variables such as human population, season (etc.) as explanatory variables, but am not sure which model to use. Does anyone have any suggestions?   I have been doing some reading and am not sure if a hurdle model or a zero-inflated model would be best.

I wonder if there is a clear-cut difference between the so-called zero-inflated distributions (models) and so-called hurdle-at-zero distributions (models)? The terms occur quite often in the literature and I suspect they are not the same, but would you please explain me the difference in simple terms?


I failed to upgrade MySQL server. Here's what I tried:  I first issue this command to update the package list:   sudo apt-get update   Then, upgrade by:  sudo apt-get upgrade   It shows the following error:  Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  mysql-server-5.5 : Depends: mysql-server-core-5.5 (= 5.5.28-0ubuntu0.12.04.2) but 5.5.31-0ubuntu0.12.04.1 is installed E: Unmet dependencies. Try using -f.   Apparently a newer version is installed (but why? I didn't install manually). Okay, As it suggests, I issue the command to attempt fixing:  sudo apt-get -f install   Here is the output:  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following extra packages will be installed:   mysql-server mysql-server-5.5 Suggested packages:   tinyca mailx The following packages will be upgraded:   mysql-server mysql-server-5.5 2 upgraded, 0 newly installed, 0 to remove and 3 not upgraded. 2 not fully installed or removed. Need to get 0 B/8889 kB of archives. After this operation, 64.5 kB of additional disk space will be used. Do you want to continue [Y/n]? Y perl: warning: Setting locale failed. perl: warning: Please check that your locale settings:     LANGUAGE = (unset),     LC_ALL = (unset),     LC_CTYPE = "UTF-8",     LANG = "en_HK.UTF-8"     are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory dpkg: dependency problems prevent configuration of mysql-server-5.5:  mysql-server-5.5 depends on mysql-server-core-5.5 (= 5.5.28-0ubuntu0.12.04.2); however:   Version of mysql-server-core-5.5 on system is 5.5.31-0ubuntu0.12.04.1. dpkg: error processing mysql-server-5.5 (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                           dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.5; however:   Package mysql-server-5.5 is not configured yet. dpkg: error processing mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                           Errors were encountered while processing:  mysql-server-5.5  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   Then I try to use another command that some people suggest in the Internet:  sudo apt-get -f upgrade   Same output is produced. Apart from re-installing MySQL server, what else can I do ?  using Ubuntu server 12.04 LTS

I'm a newbie on MySQL ground so bear with me.  I've just finished upgrading 11.10 to 12.04.  Everything seemed to work without any hiccups and all my software and settings are working fine. Apart from MySQL.  When I try:  sudo start mysql   I receive an error:  start: Job failed to start   Where can I possibly diagnose what the problem is? And (hopefully) - how to sort it out?  (I disabled automatic start following advice  if that is of some importance)     Update 1:  Both outputs of:  cat /var/log/mysql.err  cat /var/log/mysql.log   are empty.  Output of dmesg | grep mysql:  [ 1401.785141] type=1400 audit(1335619832.181:25): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=16165 comm="apparmor_parser" [ 1401.791089] init: Failed to spawn mysql main process: unable to execute: No such file or directory     Update 2:  As indicated by AWinter below - it seemed that MySQL disappeared automagically after upgrade and had to be reinstalled.


I am a Indian Citizen working in  Sweden for over a year on work permit . I am planning  to visit USA on a short trip 2 weeks to meet my friend from Stockholm and back.  Is it possible to apply for a US tourist visa from Sweden embassy while being an Indian Citizen ?

As an Iranian visiting scholar, I'll be living and studying in Belgium for six months. Now, I want to take part in a summer school for ten days in the USA.   Can I apply for USA visa from Belgium while I'm residing in Belgium not as a citizen?


I'm having trouble in coming up with a formula for this series:  $$S = x + \frac1x + \cfrac1{x + \frac1x} + \cfrac1{x + \frac1x + \cfrac1{x + \frac1x}} +\cfrac1{x + \frac1x + \cfrac1{x + \frac1x} + \cfrac1{x + \frac1x + \cfrac1{x + \frac1x}} } + \cdots + a_n $$  How can I find $S$ ?  Thanks :)

$$x + \frac1x + \cfrac1{x + \frac1x} + \cfrac1{x + \frac1x + \cfrac1{x + \frac1x}} +\cfrac1{x + \frac1x + \cfrac1{x + \frac1x} + \cfrac1{x + \frac1x + \cfrac1{x + \frac1x}} } + \cdots $$  How can this series be simplified? Consider me as a high school graduate.


What causes a tension force? I can't understand why there is a tension force acting Also, let's take a simple example of tension force," a block tied to a end of the rope which is hanging". When will be the tension force larger or smaller than the weight of the block ? And why? Please answer.

What exactly is tension force and how does it act? When I saw a video on  it said that tension force is just a force by which a force is transmitted across a rope, but when I was solving related problems, it was that the tension force is acting upwards on the body which is attached to a rope. Also, how can a tension force be acting upwards on the lower part of the string and downwards on the lower part of the string? In wave motion, I saw that tension is perpendicular to the string and that is what causes it to stretch. What is tension force and why does it have the directions that I mentioned and why? And how can I find its directions on bodies and in the string?


My system is currently very slow, and I'm fishing for reasons why this might be..  System is : W10x64 Pro, i5-4460 CPU @3.2GHz, 8GB PC3-12800 @ 1600MHz, 500GB SATA HDD.  Disk C: has less than 10% free space, and from what I see in Task Manager, disk usage is my main problem. From time to time the computer freezes, and I have to wait 10-15 minutes for it to release.  Just now I noticed I have 16GB of committed memory, I have no idea why. Might it be that the system is forced to write data on the HDD all the time and this is why it is so slow ?  Image from Task Manager :    EDIT. My Paging file is 8GB which explains the committed memory size.    Should I disable it and see if the RAM is enough for my usage .. I need a solution on how to get the system to work normally.

I have run two virus scans and neither of them have found anything so far (Malware Bytes and Avira Rescue). During gaming I will get Windows popups saying that my system is low of memory and recommends closing the game. This can also happen while browsing. My computer seems to become sluggish a lot and will hang up often, such as when clicking a link from a messenger program to open in my browser.   I am unsure what is causing this. My memory usage on the processes tab doesn't add up to such a high percentage of my actual memory.    As a side note, is my Disk Usage supposed to spike up to 100% sometimes? Research seems to say so.


We have a store page using Magento. We've set up schema.org metadata to describe all products (about 16000). The  shows the data correctly.  Now, after a few months, GWT still shows only about 350 products, with a very very slowly rising tendency. All products shown are correct, but there are a ton more products not showing up. Is there a known reason why Ggoogle would not pick up most of the products? A sitemap containing all available products is regularily comitted.

We have added some schema.org markup to a dozen of webpages on our website to provide rich snippets in Google SERP (different types, such as authorship and reviews). They are correct - at least, Google's Structured Data Testing Tool reports this.  However, even after a week we see the message "We do not detect any structured data on your site" in the Structured Data section in Google WMT. How long can it take while the Google bot detects our rich contents? Is there a way to speed up this process anyhow?


Lets say there exist some enterprising young bard 3/ sorcerer 1 named Kirk.   Deciding to uphold (long past) family tradition, he has chosen to go out and have a little half-dragon of his own.   He chose Persuasion as his expertise skill, and is of a dragon bloodline himself, gaining the Dragon Ancestry perk.  Do they stack? Not the same ability, and both say "Your proficiency is doubled" when they activate. Granted, it would only happen when dealing with dragons. But there are certainly worse times to ramp up your charm.

Do features that allow you to add twice your proficiency bonus, under some other name, stack with Expertise?  For instance, , with  as applied to History checks, to identify the origin of stonework.  The text of Stonecunning is reproduced below:     Whenever you make an Intelligence (History) check related to the origin of stonework, you are considered proficient in the History skill and add double your proficiency bonus to the check, instead of your normal proficiency bonus.   And, for good measure, the relevant portion of Expertise:     Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies.


I'm looking for a short YA series of books about a number of kids with superpowers. Each book focuses on one kid, who at the end meets the other surviving kids and joins them. They are all on the run from a race of supernatural beings, possibly aliens. The mood of the series was somewhat dark, and some of the kids may have died throughout the series.  The most memorable thing I remember was that the antagonists wear sunglasses hiding eyes that seem like dark metallic tunnels, but they otherwise look like normal people. The superpowered kids all had golden blood as well, if I remember correctly. Any ideas?

I vaguely remember reading a young-adult book about a group of kids.  The kids turned out to be aliens, and the one identifying mark they had was that their blood was silver (or something else)?  I think the kids also have powers.  I vaguely remember a cover that had a gaping mouth and something that looked like they were supposed to be sound waves coming from it.  Does anyone know what this is?


I have a company that was incorporated in November 2015 as a S Corp.  There was no activity at the company for November / December 2015 and a tax return was not filed for 2015.  I found that even with no activity, all S Corps are required to file a yearly tax return.  The penalty for this seems to be $195 per month per shareholder (we have two shareholders in the company) with the max # of months capped at 12 (so a total of ~$4,800 = 2 x $195 x 12).  I am currently floating the possibility of selling my stake in the company.    Who is liable here for my half of the penalty ($2,400) - the corporation or me?  If I sold my share in the company right now, and the 2015 return was filed as late somewhere down the line - would I be liable for the penalty?

I have a small one person s-corp in USA. It's now almost first day of summer; however, I still haven't filed my corp taxes due to some personal issues. What do I do at this point? Should I just fill my taxes using TurboTax? What is the late fee?


I've made a very simple (inaccurate) program that calculates your age. I want to make it accurate by calculating leap years and taking into account that every month has a different amount of days. Any help how to do that and where to start? Thanks!   using System;  public class Program {     public static void Main()     {         float currentDay = 22;         float currentMonth = 2;         float currentYear = 2020;          Console.WriteLine("Enter your date of birth: (eg: 13/04/1998)");         Console.Write("Day: ");         int dayNum = Convert.ToInt16(Console.ReadLine());         Console.Write("Month: ");         int monthNum = Convert.ToInt16(Console.ReadLine());         Console.Write("Year: ");         int yearNum = Convert.ToInt16(Console.ReadLine());          float birthDay = (currentDay - dayNum) / 365;         float birthMonth = (currentMonth - monthNum) / 12;         float birthYear = currentYear - yearNum;          float age = birthYear + birthMonth + birthDay;          Console.WriteLine("Your age is: " + age);        } }

Given a DateTime representing a person's birthday, how do I calculate their age in years?


See below gif, as it shows the issue clearly:    When clicking on the edit button, it doesn't actually get rid of the edit link, and clicking it multiple times causes undesired behavior. (This can simply happen if a user double clicks on the edit button by accident.)

Help!!!  I don't know quite what happened, I was getting frustrated, trying to somehow escape the backticks inside the code formatting. I clicked the edit button too many times, and then the above happened. Perhaps I clicked it to fast, I don't know, but I then got lots of boxes.    Edit:  Based on a test case below, the problem is simply caused by pressing edit while you still have an edit box open. They all go away when you press cancel anywhere once. This makes it much easier to reproduce, and, while not very important, perhaps still something to be fixed.  Note on the pattern:  When you click the first time, you get one box, as normal. When you click again, you get one extra empty box at the top, and another normal box above that. At each click, one empty box is added per existing normal boxes, plus one normal box. What is going on?


Mentioned the word) Radian-unit-sign, rad, unit, radian, pure number, ratio, symbol, speed, distance, time

Can't understand why we say that radians are dimensionless. Actually, I understand why this is happening:  theta = arc len / r   Meters/meters are gone and we got this dimensionless. But also we know that angle 57.3 degrees = 1 rad. So, can we use it as dimension?  In such a situation we can say that degrees are also dimensionless, because 1 degree = 1/360 of circle.  How we define the value is dimensionless or not? Why meter is not dimensionless? Where I'm wrong in my conclusions?


I am quite absent minded, and I forget everything I want to install - especially after a restart  Is there a way that I can set another command to run (in a separate terminal, of course) when the currently running instance of apt has finished?  I expect this could be done by repeatedly trying to run the command, but I'm looking for something more like this:  WHEN apt EXIT = True; do run next-apt-command   I also expect that it could check the lock file, to see if it is available?

I have seen many softwares such as Update Manager and Synaptic Package Manager, they wait if some other program is using the /var/lib/dpkg/lock and is locked. How can we do this through the Terminal? I saw apt-get's manual but didn't find anything useful.


Currently I'm running opensuse 13.2 and I want to update it to a (ubuntu)linux with the newest kernel the 4.9.xy release as mentioned at .   Is the latest kernel 4.9.xy version available for Ubuntu?  or - Can I update this - after having installed Ubuntu without any risk of crashes? I'm updating my kernel regularly as provided by the Update Manager..  Is  there a way to install Ubuntu - and afterwards easily upgrade to the newest kernel?

Currently I'm running Linux-3.0 and I want to update it to Linux-3.3.1 the latest stable kernel release as mentioned at . Can I update to 3.3.1 in Ubuntu without any risk of crashes? I'm updating my kernel regularly as provided by the Update Manager..Currently I have Linux-3.0.0.17..Can I update?  NOTE:  The latest kernel version any user is supposed to use in Ubuntu is updated automatically via the Update Manager, so no action is normally required by user regarding kernel upgrades. What the question author is referring to is mainline kernel, see:


I'm looking for a technical term for using a noun as its own verb form where such usage is not extant. For example, using intellect as a verb (to intellect). Is there such a term? It doesn't seem to be a neologism or an example of metonymy.

This is in very common use on the internet. I just read this:     "[The] hotel employee walks in, I say "uh, puppy" and she just NOPEd the [heck] out of the room."   This is often done by adding 'd to the word.


Let $$ \lim_{x\rightarrow 0} \frac{(x + 1)^{\frac{1}{x}} - e}{x} = ? $$  How would you calculate it's limit? I thought using l'hopital rule, but it then becomes something nasty, as the differentiate of $(x + 1)^{\frac{1}{x}}$ isn't simple.

I tried to evaluate $$\lim_{x\to0}\frac{(1+x)^{1/x}-e}x$$but all my efforts were in vain . L'Hospital rule becomes very complicated.


I found a , and the first is this:     Prove that   $$e^\pi > \pi^e$$   Hint: Take the natural log of both sides and try to define a suitable function   that has the essential properties that yield [the] inequality.   Taking $ln$ of both sides gets $$\pi > e \cdot \ln(\pi)$$  I thought of replacing the $\pi$ with $\arccos(-1)$ for $$-1 > \cos(e \cdot \ln(\pi))$$ and then maybe $f(x) = \cos(e \cdot \ln(x))$, but I have no idea where to go from there, or if that's the right direction. Can anyone offer hints as to the next steps?

How can I  compare (without calculator or similar device) the values of $\pi^e$ and $e^\pi$ ?


My problem:  I used the following iptables command:  iptables -t nat -A PREROUTING -p udp -i eth0 --dport 52220 -j DNAT --to-destination 192.168.19.40   192.168.19.40 is the IP address of a virtual machine, which is pingable:  root@Helium ~ # ip route get 192.168.19.40 192.168.19.40 dev untrusted-vm-br  src 192.168.19.1      cache  root@Helium ~ # ping 192.168.19.40 PING 192.168.19.40 (192.168.19.40) 56(84) bytes of data. 64 bytes from 192.168.19.40: icmp_seq=1 ttl=64 time=0.181 ms   However, UDP packets incoming from eth0 are not forwarded:  root@Helium ~ # tcpdump -i eth0 udp port 52220 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 20:36:15.425602 IP <reverse_hostname_of_my_home>.19834 > Helium.52220: UDP, length 160 20:36:23.621066 IP <reverse_hostname_of_my_home>.19834 > Helium.52220: UDP, length 160 ^C 2 packets captured 2 packets received by filter 0 packets dropped by kernel root@Helium ~ # tcpdump -i untrusted-vm-br udp port 52220 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on untrusted-vm-br, link-type EN10MB (Ethernet), capture size 262144 bytes ^C 0 packets captured 0 packets received by filter 0 packets dropped by kernel   I have similar port redirections for TCP ports, which all work as expected.  What am I doing wrong? Is there something specific to UDP I missed?    Additional debugging information:  IPv4 forwarding is enabled:  root@Helium ~ # cat /proc/sys/net/ipv4/ip_forward 1   Using iptables -v shows that no packet matched my iptable rule:  root@Helium ~ # iptables -L -v -t nat Chain PREROUTING (policy ACCEPT 9680 packets, 612K bytes)  pkts bytes target     prot opt in     out     source               destination          [...]     0     0 DNAT       udp  --  eth0   any     anywhere             anywhere             udp dpt:52220 to:192.168.19.40   I tried using iptables -j LOG:  iptables -t nat -A PREROUTING -p udp -j LOG --log-prefix "[iptables log udp]"   Which gives:  Aug 10 17:01:33 Helium kernel: [1824208.192607] [iptables log udp]IN=eth0 OUT= MAC=<mac_address_of_my_eth0> SRC=<ip_address_of_my_home> DST=<ip_address_of_eth0> LEN=188 TOS=0x00 PREC=0x00 TTL=51 ID=1476 DF PROTO=UDP SPT=19834 DPT=     Linux/iptables version:  root@Helium ~ # uname -a Linux Helium 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-2+deb8u3 (2016-07-02) x86_64 GNU/Linux root@Helium ~ # iptables --version iptables v1.4.21

My iptables DNAT rules don't work until reboot. If I reboot my server, all of the rules work.  Desciption of the architecture :  Tens of hosts (senders) send some UDP packets (one-way on a specific port 9999) to my Linux router. This Linux router use iptables to forward those packets to several hosts (receivers).  senderX 10.0.0.X  ====> Linux router with iptables ====> receiverY 10.0.1.Y  The linux router have two network cards eth1 10.0.0.1/24 (senders side) and eth0 10.0.1.1/24 (receivers side).  Iptables setup :   ip_forwarding is activated all of the default policies are set to ACCEPT one iptables rules exist per sender, here is an example :    iptables -t nat -A PREROUTING -s 10.0.0.2 -i eth1 -j DNAT --to-destination 10.0.1.123   Network setup :  ip addr show :  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo     inet6 ::1/128 scope host        valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000     link/ether 54:9f:35:0a:16:38 brd ff:ff:ff:ff:ff:ff     inet 10.0.1.1/24 brd 10.0.1.255 scope global eth0     inet6 fe80::569f:35ff:fe0a:1638/64 scope link        valid_lft forever preferred_lft forever 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000     link/ether 54:9f:35:0a:16:3a brd ff:ff:ff:ff:ff:ff     inet 10.0.0.1/24 brd 10.0.0.255 scope global eth1     inet6 fe80::569f:35ff:fe0a:163a/64 scope link        valid_lft forever preferred_lft forever   Symptom :  After adding a set of rules, some of the rules doesn't work. And I can see with tcpdump that UDP packets are no more routed and packets are rejected.  tcpdump -n -i eth1 host 10.0.0.2 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes 16:12:58.241225 IP 10.0.0.2.56859 > 10.0.0.1.9999: UDP, length 1464 16:12:58.241285 IP 10.0.0.1 > 10.0.0.2: ICMP 10.0.0.1 udp port 9999 unreachable, length 556    If I flush all the rules and reinject them in iptables, rules that was not working still not work. If I reboot my server all the rules work fine.   Analysis done :  I have added a rule to log a specific sender which is not working :  iptables -t nat -A PREROUTING -s 10.0.0.2 -i eth1 -j LOG --log-prefix='PREROUTING LOG :'   But this rule doesn't log anything. Packets are coming because I see those in tcpdump but they are not logged. Also with the -v option in iptables, I don't see counters increasing for this rule.  If I apply the same rule before it stop working, I have some logs.  Question :   Is there any limits on UDP forwarding in iptables ? How I can troubleshoot this issue ?


A lot of people seem to use VLQ when they really mean Not An Answer. Many . I, personally, know the difference but find VLQ to be a rather rare flag if used properly.   However, "very low quality" is much clearer than "not an answer", and I find users (even Community!) using VLQ where NAA makes more sense. This is a problem, but I don't have any idea how to fix it so I'll jist focus on the symptoms.  When an NAA flag appears in the queue, there is a direct option to convert to comment. Could VLQ have this as well? It's much easier to handle flags from within the queue whenever possible.  Suggestions on how to improve the central problem also welcome.

Currently, if an answer is marked as "Very Low Quality", we are only given options to delete the post, or ignore the flag.  However, there are many times when the answer should be converted to a comment, but we can't, because the flag was wrong.  If an answer is flagged as "Very Low Quality", then I'd like to see the same tools made available for the post as if it was flagged "Not an Answer" (including , if it is implemented).  This would help the workflow considerably.  It should be noted that this is a technological solution to a community problem; we have people who are flagging posts that are not an answer as very low quality (and conversely, posts that are "Not an Answer" as "Very Low Quality", such as link-only answers).  Given that most flags are to be taken as an indication that something is wrong, and that we shouldn't nitpick over the type of flag (only if it was helpful or not, ), we should have access to all of the tools for an answer no matter what the flag is (because we aren't going to change the social conditioning, and rightfully so).


Let $A=\{A_1,\ldots,A_n\}$ be a partition of a set $\Omega$ and let $F=\sigma(A)$. Prove that $X : \Omega \to \Bbb R$ is a random variable if and only if it is constant on each element of the partition.  I am trying to do the proof by contradiction but it seems the wrong way. Any hint? Thanks in advance for your help.

Let $\mathcal{G} = \{A_1, \ldots, A_n\}$ be a partition of a set $\Omega$, $\mathcal{F} = \sigma(\mathcal{G})$. Prove that $X : \Omega\to\mathbb{R}$ is a random variable if and only if it is constant on each of the partition elements $A_j$.  I have attempted both directions but faced some difficulties to continue writing the proof. I have also consulted some sources that have a not so clear proof.  Here is the proof: We know that $$\sigma(\mathcal{G}) = \left\{\sum_{i\in I}A_i : I \subset \{1,\ldots,n\}\right\}.$$ ($\Leftarrow$) Let $B\in \mathcal{B}(\mathbb{R})$. In this case $X(\omega) = a_i$, $\forall\omega\in A_i$ for some constants $a_i$, (then I am not sure how to proceed to show that it is a random variable), the proof says that $X = \sum_{i\in I}^n a_i \mathcal{{1_A}_i}$ and $\{X \in B\} = \sum_{i : a_i\in \mathcal{B}}A_i\in \mathcal{F}$, so $X$ is a random variable.  My question is why are we concluding or defining $X = \sum_{i\in I}^n a_i \mathcal{{1_A}_i}$ (what is the purpose), in other words I don't understand it's flow of reasoning.  ($\Rightarrow$) We use proof by contradiction: If $X$ is not constant on $A_i$, then $\exists i_0$ such that for some $\omega_1, \omega_2 \in A_{i_0}$ one has $a:= X(\omega_1) \not= X(\omega_2)$. Then I am not sure how to proceed from here.  Many thanks in advance.


i wish to delete a local directory if it already exists. below is my code:  import sys import os from pyspark import SparkContext from pyspark import SparkConf  conf=SparkConf().setAppName('pyspark') sc=SparkContext(conf=conf)  data=sc.textFile('file:///home/cloudera/Downloads/SAN_SALES_EXTRACT_TRANS_LEVEL_D0906.txt') datamap=data.map(lambda x: ((str(x.split(',')[1]).strip(),int(x.split(",")[0])),float(x.split(",")[10]))) datagrouped=datamap.reduceByKey(lambda x,y: x+y) if (os.path.exists("file:///home/cloudera/Downloads/store_perday_rev")):         os.remove("file:///home/cloudera/Downloads/store_perday_rev") else:         datagrouped.sortByKey().saveAsTextFile("file:///home/cloudera/Downloads/store_perday_rev") #for i in datagrouped.sortByKey().take(20): #       print(i)   It doesn't delete the directory. What am i doing wrong?

I am getting an 'access is denied' error when I attempt to delete a folder that is not empty. I used the following command in my attempt: os.remove("/folder_name").   What is the most effective way of removing/deleting a folder/directory that is not empty?


I got my hands on a couple of wyse thin clients   I want to use them for RDP purpose. The original plan was to install Tinycore on them and to use Rdesktop to rdp to the server, but the latest rdesktop (1.7) on Tinycore does not support windows server 2008 R2 (had some issues with my pointer device not showing on screen).   Now what I am looking for is a Linux distribution that uses under 128MB of flash memory and under 512MB of RAM. The OS must be capable of running rdesktop 1.8.3.

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


I am developing a windows desktop application in C# and I want to disable screen captures of this application.  Can I get suggestions for this?

I have a requirement that an application I am working on prevent the user from being able to easily capture the contents of the screen.  I have communicated that there is no feasible way to completely prevent this from happening, but I'm looking for methods to introduce some hurdles to the process.  I'm using C#/.NET 2.0 and WinForms


I have disabled my System Integrity Protection: $ csrutil status System Integrity Protection status: disabled.  when I add soft connection: ln -s /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include /usr/include  there still print error: ln: /usr/include: Read-only file system   My MacOS version is: macOS Catalina 10.15.2.

Currently Running: macOS Catalina 10.15.1 Issue: Ever since I upgraded to Catalina, macOS is not allowing me to change read and write permissions on system protected files, hence, I am not able to tweak the system as per my likes and dislikes. Steps Tried To Solve The Issue: SIP, always remains . So, no question arises regarding any conflict with system integrity protection. I have also tried to force change the permissions on the system files I want to edit using certain brute force commands, which I can't recall the name of, right now. But, I have tried. As of now, I am still unable to change read and write permissions on system protected files and resources.


Do you think he will come?     or     Do you think  he would come?     Which is the correct form? If both are correct, What is the difference in their meaning? I have seen similar questions, but the are not in interrogative form. As I am a new learner, I just wanted to learn clearly in various forms

Consider the following sentence     It will/would rain tomorrow.   I understand "would" usually means something that is really improbable.  So "it would happen" means it might happen but it is very unlikely; while "it will happen" means it is going to happen  But what if I want to say      It will not happen?   Because the meaning of "it will not happen" represents something that is unlikely or, worse still, not going to happen, shouldn't it be more accurate to say "it would not happen"?  However, to contravene the aforesaid suggestion - if I am confident that the thing is not going to happen, should I use "will" to indicate the definite nature of my statement?  To further complicate the issue, what if I want to say     I think you will not be able to do it.    or      I think you would not be able to do it.    Which one is more accurate/correct,  given that "I think" already conveys a sense of "less than definite" and "will/would not be able to" conveys the same sense as "unlikely"?


I'm trying to dual boot with ubuntu. So, create a new partition/ree unallocated space in Windows 8 for ubuntu. But then since its a dynamic disk, ubuntu doesn't detect free unallocated space.  When I list the drives in DISKPART, it list all my 3 current partitions into 1 major DISK0. There are no other disks.    I was thinking if I could create one extra disk and convert it to basic volume and use this for ubuntu.  I don't want to lose my Windows 8 installation, C drive softwares, D drive data.  How should  do it?

I've been trying to install 12.04 for a while now, I'm running on Windows 7 and I already made the partition (it's dynamic). I've tried booting from a disc and also the Windows installer. I haven't tried used any repair-boot programs or anything. Every time I tried to load from either, I get an error:  command=C:\windows\sysnative\bcdedit.exe /set {03f9077f-661f-11e1-845a-d08b36406c3d} device partition=U;  retval=1  stderr=An error has occured setting the element data. The request isn't supported  stdout=   Then after that, it makes a log file with information that I don't understand.  If it is simply due to the fact of it being a dynamic partition, someone please help. If it is more extensive, anyone with details on possible solutions or definite ones please express them.


I think SE should permit us to select different names for different websites. Also I can't seem to edit my name and status. Is there an option for editing these?

It would be nice to update the profile page from within the app.  Perhaps not many people update their profiles more frequently, but when required to do so, I would prefer to do it from the app instead of the mobile browser.


I am a Russian citizen. I have Schengen visa type C valid till 01/03/2020 and I am going to change my name and I will keep my surname as it is.   Can I travel with my new passport with new name and old passport which has a valid Schengen visa in the new year to Europe?

I'm an Indian National. I have a Type C Schengen Business Visa which is valid from 26-11-2015 to 26-11-2020. I received it when I intended to travel to Netherlands, although I have not used it.   When I applied for a spouse endorsement, the passport on which the visa is stamped was cancelled and a new passport was issued.  Now, I plan to travel to Italy on business from July 8th to 16th.    Can travel with the same visa in old passport, or should I cancel the existing visa and apply for a new one?  I contacted the Netherlands Embassy call center (not VFS Netherlands) which responded that I can use it without any issues. However, they have not confirmed it by email.   I asked about any immigration issues in Italy and was told me that, if I have a valid itinerary and invitation letter from the office, there should be no problem. I was also told that Italian immigration authorities are able to contact the Dutch, if necessary.   I emailed the Italian Embassy in Mumbai (visa.mumbai@esteri.it) and await its response.


So I am getting an unresolved external symbol error and I can't figure out why. All files exist in the same project and the compiler seems to be generating all the obj files. I am deriving from a template class so I am thinking maybe I am not declaring my derived methods properly. I am using the visual c++ compiler in VS 2012.  BaseClass.h  template<class T> class BaseClass { public:     BaseClass() {}      virtual ~BaseClass() {}      void Foo(); }   BaseClass.cpp  #include "BaseClass.h"  template<class T> void BaseClass<T>::Foo() {     cout << "hello"; }   SomeClass.h  #include "BaseClass.h"  class SomeClass : public BaseClass<long> {     public:        SomeClass() {}         void DoSomething(); }   SomeClass.cpp  #include "SomeClass.h"  void SomeClass::DoSomething() {      Foo(); // link error      this->Foo(); // also gives link error      BaseClass<long>::Foo(); // also gives link error }   So method DoSomething() can't seem to invoke anything from its base class due to link error. Is there something obvious here I am doing wrong?

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'm trying to do some analysis on road accidents.   I have :   a .csv with lat,long data of road accidents  a .shp with the road network   When I create a new layer from .csv, it is automatically assigned to WGS 84 epsg 4326.  The road networks instead is  WGS 84 32N epsg 32632  The layers overlap when using the different SRs. The problem is when I change them to a uniform SR (that is, when creating a new shp of road accidents with epsg 32632), they don't overlap anymore and can only be visualized one at time.  Any ideas?   I'm using Qgis 2.18 (but the same with Qgis 3.0)

I have a series of layers of lines (shapefiles) in My Project. The CRS of some are different and to merge them they all must have same CRS.  When I use Processing/Toolbox/Qgis_algorithims/Reproject_layer the reprojection only works if it is allowed to save to temporary file somewhere (it will not change the CRS when I reproject if I try to save and replace it in My Project directory);   I must remove the original from the layer list and reproject the temp file (without changing the CRS) to get it into my project and name it appropriately.  Is there a better way to reproject a layer in Qgis?


I applied for a UK standard visit visa to the UK. I have lived legally in the UK for about 6 years while studying. I applied to extend my stay but was refused, so I appealed under article 8 of the European Convention on Human Rights, which failed. I returned to Pakistan voluntarily.  Now, after 3 years in Pakistan, I applied for a visa, but it was refused on the grounds that I would not leave the UK and that my circumstances in Pakistan are not strong enough for me to want to return.  During my earlier visa extension request appeal, the judge had stated that I have strong ties with Pakistan and I should return to my country. That is contradictory; the judge said I had strong ties but, today, the Entry Clearance Officer said that my situation is not strong, despite bank statement, family agricultural land, and my savings and accounts. What should I do?

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


I'm doing some experimenting with closures in Javascript, and with AngularJS  directives (1.x) in particular.   To put it simply, I am wondering why ScenarioOne correctly captures the variable message that we want, while ScenarioTwo does not. Why does the IIFE not capture and maintain the desired value of message when it invokes itself?  SCENARIO ONE   // WORKS. Displays 'We want this message'    var message = 'We want this message';    element.bind('click', (function(){     var msg = message;   // <-- MAGIC ?     return function(){       element.append('
Value of message: ' + msg + '
');     };   })());    message = 'We DON\'T want this message';   SCENARIO TWO   // DOES NOT WORK. Displays 'We  DON'T want this message'   var message = 'We want this message';    element.bind('click', (function(){     return function(){       element.append('
Value of message: ' + message + '
');     };   })());    message = 'We DON\'T want this message';   I would like to understand, what are the magic mechanics (see line denoted <-- MAGIC ) of that assignment? What is the general rule about this? Do all variables that you want from an outer scope need to explicitly assigned to a new variable inside the IIFE?  Here is a working Plunkr of all this:

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.


Find a sequence of differentiable functions $\{f_n\}$ on $[0,1]$ such that $f_n \to 0$ uniformly, but $\{f_n'(1/2)\}$ does not converge to $0$.   I have tried to find an example which follows above condition, but failed to approach. Please help me!

Give a sequence $(f_n)_{n\in \mathbb{N}}$ of differentiable functions which uniformly converge to $0$, but for which the seqeunce $(f_n')_{n\in \mathbb{N}}$ of the derivatives isn't even pointwise convergent.    I found this one in my textbook marked as "Fun things to solve" and although it may be fun, it's kind of hard to do.   To be honest I already failed at the first hurdle. I couldn't even find a sequence of functions which uniformly converges to $0$.   Is there a certain way of dealing with this kind of problem? Because it seems kind of hard for me to come up with sequences without a mathematical of way of doing so (or maybe there is a mathematical way I just don't know yet).


I'm not sure which one is correct: "The Physical Therapist Organization" or "The Physical Therapists' Organization".  I'm leaning more towards without the plural-possessive but will I be grammatically wrong? Please don't respond with saying that I can use "Therapy" instead. I need to use the word "Therapist" or "Therapists'". Any help will be well appreciated.

I know that children’s books is correct, but for some reason I want to say kids books, even though I know that it’s a plural possessive noun ending in an s.   A quick search on the web turns up Barnes & Noble, who have a web page title that reads “Children's Books, Kids Books”.   Is the major bookseller wrong here? Or is there some exception I don’t remember?  More simply, is it kids books or kids’ books — and why?


I was asked this question on a quiz and stated that this statement was true. My logic being, $\{\}$ is an element in all sets. The ordered pair can be rewritten as $\{\{1\},\{1,2\}\}$ as a set. What is wrong in my thinking? The teacher has not provided me with a proper explanation.

Is "empty set" an element of a set? For example:  is this FALSE?:  0 ∈ {1,2,3}


When i load html content by using ajax, the jquery events on loaded html is not work.  For Example-  I have a jquery function-  $('.test').on('click', function(){   alert('hi'); });   ajax response :

test data

   Now clicking on ajax loaded data is not firing jquery On click event as i defined.

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 am just learning linkedlists and trying to insert a node at the head. Here is my code:  Node Insert(Node head,int x) {      Node tmp = new Node();      if (head == null) {         head = tmp;         tmp.data = x;      }     tmp.data = x;     tmp = head;     tmp.next = head;      return tmp; }   I am not sure what is going wrong. My logic:   Create a new node 'tmp' assign that value of 'x' and the reference to tmp would be null MAke tmp's next i.e. reference to the head of the linkedlist if head is null then tmp's data becomes head's data and tmp's reference become null

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 seen the advice of . The reason seems to be that this is when these funds pay out dividends which is taxable.  However,    Capital gain is taxable anyway, no matter when I invest. So I should still make my automatic investment during end-of-year, correct? The only reason a person shouldn't start investing at year-end is because he will suffer the tax bill without the benefit of having invested throughout the year prior. Even if he start investing at year end, can he still soften the blow by re-investing the dividend instead of cashing out? That way, he does not have to pay short-term capital gain tax on the cashed-out dividend. If this "softening" works, how much does it help? How bad is it to start investing at the end of the year?

Should I expect prices of mutual fund shares to go up in anticipation of dividends, down after dividends have paid out ... or just trust that the market has already reacted to that and the price is basically fair throughout the period?  (I've generally been paranoid and tended not to play with my funds around this time of year, but that may be pure superstition.)  Clarifications: USA, open-ended index funds are my immediate interest, but the answers would be most general if we could cover some of the other varieties (and, if folks are so inclined, locations).


Which one of the following two sentences is the correct sentence?   "20% of the participants believe that the world is flat." "20% of the participants believes that the world is flat."   What grammatical rules govern the choice of the correct sentence here?

Does a percentage require a singular or plural verb, for example, do we say ten percent "go" or "goes"?


Th following is the full code that produces the image shown below:  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage[english]{babel}  \usepackage{amsthm} \usepackage{amsmath} \usepackage[left=1.5in, right=1.5in, top=0.5in]{geometry}   \newtheorem{definition}{Definition} \newtheorem{theorem}{Theorem}  \theoremstyle{remark}  \begin{document}     \title{Extra Credit}     \maketitle      \begin{definition}         If f is analytic at $z_0$, then the series          \begin{equation}             f(z_0) + f'(z_0)(z-z_0) + \frac{f''(z_0)}{2!}(z-z_0)^2 + \cdots = \sum_{n=0}^{\infty} \frac{f^{(n)}(z_0)}{n!}(z-z_0)^n         \end{equation}          is called the Taylor series for f around $z_0$.     \end{definition}      \begin{theorem}         If f is analytic inside and on the simple closed positively oriented contour $\Gamma$ and if $z_0$ is any point inside $\Gamma$, then         \begin{equation}             f^{(n)}(z_0) = \frac{n!}{2\pi i} \int_{\Gamma} \frac{f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta \hspace{1cm} (n=1,2,3, \cdots )         \end{equation}     \end{theorem}     \hrulefill    \begin{theorem} If f is analytic in the disk $|z-z_0|<R'$, then the Taylor series $(1)$ converges to $f(z)$ for all $z$ in this disk.  \end{theorem}  \begin{proof} Suppose that the function \textit{f} is analytic in the disk $|z-z_0|<R'$. We can define a positively oriented contour $C$ as $$ C:=\Big\{z:|z-z_0|=\frac{R + R'}{2}, 0<R< R'  \Big\}.$$ Letting $\zeta$ be an arbitrary point on $C$ and applying Theorem 1 to $(1)$, we get   \begin{equation} \sum_{n=0}^{\infty} \frac{(z-z_0)^{n}}{2\pi i} \int_{C} \frac{f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta. \end{equation}\\   Or equivalently, we have that   \begin{align*}   \sum_{n=0}^{\infty} \frac{(z-z_0)^{n}}{2\pi i} \int_{C} \frac{f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta   &= \frac{1}{2\pi i} \sum_{n=0}^{\infty} \int_{C} \frac{(z-z_0)^{n}f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta    \\ &= \frac{1}{2\pi i}\int_{C}\sum_{n=0}^{\infty} \frac{1}{\zeta - z_0}\frac{f(\zeta)}{\frac{(\zeta - z_0)^n}{(z-z_0)^n}}d\zeta                      \\ &= \frac{1}{2\pi i} \int_{C} \frac{f(\zeta)}{\zeta - z_0}\sum_{n=0}^{\infty}\left( \frac{z-z_0}{\zeta - z_0}\right)^{n} d\zeta \                    \end{align*}     The above image is created using   \begin{align*}   \sum_{n=0}^{\infty} \frac{(z-z_0)^{n}}{2\pi i} \int_{C} \frac{f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta   &= \frac{1}{2\pi i} \sum_{n=0}^{\infty} \int_{C} \frac{(z-z_0)^{n}f(\zeta)}{(\zeta - z_0)^{n+1}}d\zeta    \\ &= \frac{1}{2\pi i}\int_{C}\sum_{n=0}^{\infty} \frac{1}{\zeta - z_0}\frac{f(\zeta)}{\frac{(\zeta - z_0)^n}{(z-z_0)^n}}d\zeta                      \\ &= \frac{1}{2\pi i} \int_{C} \frac{f(\zeta)}{\zeta - z_0}\sum_{n=0}^{\infty}\left( \frac{z-z_0}{\zeta - z_0}\right)^{n} d\zeta \                    \end{align*}   which is extracted from the full code above. How can I resize the second line of the image, so that all the characters are the same size?

I am trying to size the numerator and denominator of the below equation so that they are equal in size.  I have not had much luck suggestions are appreciated.  \begin{equation} \sum_{i=1}^{n} \frac{\frac{cf_{n}}{(1+i)^n}} {\displaystyle\sum_{i=1}^{n}\frac{cf_n}{(1+i)^n}} , n_{i} \end{equation}


If one fails, then he must simply try harder. If one fails, then one must simply try harder.   I have been trying to find the answer to this one for some time now. Some books and websites say second is correct while others say they both are same. Can someone explain which one is grammatically correct?

(a) When one reads the Hindi literature of the twentieth century, he finds a striking contrast between the writings of Munshi Premchand and later day writers of popular Hindi fiction.      (b)  When one reads the Hindi literature of the twentieth century, one finds a striking contrast between the writings of Munshi Premchand and later day writers of popular Hindi fiction.   According to me, (b) should be the correct one as "one" cannot be used interchangeably with other pronouns when referring to the same thing. But the correct answer is (a). Can someone explain?


Does Mahalanabis Distance have something to do with Min-Max normalisation?  I know that it has something to do with Z-score normalisation, but when I tried Mahalanabis Distance on the Min-max normalised data, it gave me the same result? Why is that? Did I miss anything? Many thanks.

I'm studying pattern recognition and statistics and almost every book I open on the subject I bump into the concept of Mahalanobis distance. The books give sort of intuitive explanations, but still not good enough ones for me to actually really understand what is going on. If someone would ask me "What is the Mahalanobis distance?" I could only answer: "It's this nice thing, which measures distance of some kind" :)   The definitions usually also contain eigenvectors and eigenvalues, which I have a little trouble connecting to the Mahalanobis distance. I understand the definition of eigenvectors and eigenvalues, but how are they related to the Mahalanobis distance? Does it have something to do with changing the base in Linear Algebra etc.?  I have also read these former questions on the subject:       I have also read .  The answers are good and pictures nice, but still I don't really get it...I have an idea but it's still in the dark. Can someone give a "How would you explain it to your grandma"-explanation so that I could finally wrap this up and never again wonder what the heck is a Mahalanobis distance? :) Where does it come from, what, why?   UPDATE:   Here is something which helps understanding the Mahalanobis formula:


I am trying to use left arrow key in name.write(u\2190) but the below error appears every time.  outfile.write(u'\u2190\u2190') UnicodeEncodeError: 'ascii' codec can't encode characters in position  0-1: ordinal not in range(128)

When piping the output of a Python program, the Python interpreter gets confused about encoding and sets it to None. This means a program like this:  # -*- coding: utf-8 -*- print u"åäö"   will work fine when run normally, but fail with:     UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position 0: ordinal not in range(128)   when used in a pipe sequence.  What is the best way to make this work when piping? Can I just tell it to use whatever encoding the shell/filesystem/whatever is using?   The suggestions I have seen thus far is to modify your site.py directly, or hardcoding the defaultencoding using this hack:  # -*- coding: utf-8 -*- import sys reload(sys) sys.setdefaultencoding('utf-8') print u"åäö"   Is there a better way to make piping work?


How I can prevent my laptop from sleeping when a large file is downloading? Notice that I use windows 8 and the downloader program is IDM where I can find the related settings, in IDM or Windows? Thanks for any help

I'm used to not shutdown Windows but to sleeping it. I set up power button (PB) action to do it. When I want to shutdown I must go to start -> Shutdown. That's OK.  Now I think of a mechanism that will be hooked up to a PB. Should be started after I press PB but before OS will go to sleep. Something that will check few conditions (i.e. running backup, running AV scan, ...) and if true (something is running) prevent go to sleep.  Optionally: It would be nice to start the same "mechanism" before restart and shutdown (invoked not only from Start menu, but also by other software (i.e. installers) but with option to allow some sources (i.e. UPS software)  Generally: How to run something after PowerButton but before Sleeping. How to code (C#.NET, vbs, batch (preferred)) sleep prevention (cancellation).


I'm working on a project that routes various modes of transport to one location (a school) in Arc Map 10. I have about 400 routes, so there is a significant amount of overlap as they near the school. Just for simplicity, let's say that 50 students walked, 150 drove and 200 took the bus.   What I'd like to is show the difference in modes of transport by widening the polylines as they overlap. And then, as they get close to 1 or 2 blocks from the school, have them all join. The line for students that walked to school would be 12.5%, students who drove would be 37.5%, and the students who bused would be 50%.   Can you think of a way I would be able to symbolize the data to show this? It's a really specific problem I'm working on, so I've been having trouble coming up with the right solution. What I've done so far is separate the polylines that intersect, but that's where I'm stuck.  Any help would be greatly appreciated!  Thank you!

Some common problems with displaying routes created from street data, such as bus routes, include:   Routes may overlap themselves, such as when a route takes the same road in opposite directions Routes may overlap other routes that take the same street. Routes are often overly detailed, or "noisy", owing to their derivation from street data. Indicating a route's direction unambiguously without overloading it with arrows can be a challenge.   What are some techniques for dealing with these issues in order to create a practical and usable route map, such as this ? Do you know of any such public transport maps that were produced by automatic techniques rather than manual illustration/digitization?  Specifically I am using ArcGIS 10, but solutions involving other software are welcome as well.  One technique I have had some success with for dealing with 1) is using ArcMap's  with a negative offset -- assuming the lines are oriented in the direction of travel, this will offset the lines such that the right and left-hand sides are distinct and oriented as you would expect (at least for  countries, for left-hand traffic countries one would use a positive offset). However the result tends to be a bit wonky around turns, interchanges and and U-turns, and is inflexible when dealing with multiple routes.  Another possibility that I am not very familiar with but which seems promising is  -- however, I have not had much luck in finding examples of using representations for transportation maps and whether it might fit the bill.


I want to build a binary classification tree to clasfiy wether a person is working or not and use the model for prediction. I read that unbalanced data could be a problem. Now i ask myself at which treshold is the unbalance big enough that it could yield to problems for the tree? Below you can see the table outputs for the variable to see how unbalanced the the variable is that i try to predict. I want build 2 trees for 2 different years. Is the data to unbalanced or is it okay?  > table(testSet2002$Partizipation)     0    1  1031 2229  > table(trainSet2002$Partizipation)     0    1  2361 5246  > table(testSet2015$Partizipation)     0    1  1040 2210  > table(trainSet2015$Partizipation)     0    1  2352 5265

We already had multiple questions about unbalanced data when using , , ,  and a number of other similar questions, what makes it a very popular topic! Unfortunately, each of the questions seems to be algorithm-specific and I didn't find any general guidelines for dealing with unbalanced data.  Quoting , dealing with unbalanced data     (...) heavily depends on the learning method. Most general purpose   approaches have one (or several) ways to deal with this.   But when exactly should we worry about unbalanced data? Which algorithms are mostly affected by it and which are able to deal with it? Which algorithms would need us to balance the data? I am aware that discussing each of the algorithms would be impossible on Q&A site like this, I am rather looking for a general guidelines on when it could be a problem.


I'm trying to show that if $R=\mathbb{Z}[\sqrt{p}]$ with $p$ an odd prime such that $p \equiv 3 \hspace{1mm} (\operatorname{mod} 4)$ and $I$ is the ideal generated by $2$ and $1+\sqrt(p)$ then $I^2$ is the ideal generated by $2$ I know that $$I^2=(4,2+2\sqrt{p},1+p+2\sqrt{p})$$ and that $4,2+2\sqrt{p},1+p+2\sqrt{p} \in (2)$, so I just need to prove that $2 \in I^2$ but I cannot prove it. Any ideas?

I don't know how to solve this problem. I tried to write out the sum of products in the definition of products of ideals, but that doesn't seem to lead anywhere.


When I use time and date at the end of a crontab line like backup`date +%F_%T`.sql or like backup`date%d%m%y`.sql, my crontab command doesn't work. But when I remove it, it works perfectly.  Why doesn't it work when I use time and date like date%d%m%y?

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?


A little bit of background. I did my undergraduate degree in medicine i.e. MBBS. I was always inclined towards academia and research, so I went for masters in human anatomy from UK (it was a taught program). My thesis was on the neural pathways of fear and anxiety as a result I ended up reading so much besides neuroanatomy, which turned out to be in the realms of neuroscience.   Edited  Now I want to pursue PhD in neuroscience either in Canada or EU and most if not all of the PhD programs that I've looked into ask for some sort of research experience and knowledge about Matlab or Python. But the problem is I don't have any research experience and there is no research taking place in this field in my country let alone my city. As far as programming languages are concerned, I have just started learning Matlab on my own.   Here are my questions: What are the chances of getting into a neuroscience PhD program (specifically) without any research experience or should I go for MRes in neuroscience, gain some research experience and then apply for a PhD.

Can I be admitted to graduate school in a different field from my degree?  Specific cases include:   If I've taken plenty of advanced courses in field X in the process of completing a degree in another field, can I apply to graduate school in X? What if I haven't taken many courses in X, but I have acquired a good grasp of X through self-study or working in a related field? What if I've never studied X, but I have done very well in an unrelated field?  Could I be admitted to graduate school in X on the basis of general intellectual promise, and then make up the missing background after enrollment?   Note that this question is an attempt to provide a comprehensive answer, to avoid the need for a profusion of field-specific questions on this topic (see the associated ). Please feel free to edit the question or answer to improve them.


$ \mathbf{Z}[x]$ is not PID.   we know $\mathbb Z$ is a Unique Factorization Domain, so $\mathbb Z[x]$ is UFD, but why isn't it PID (since I think $\mathbb Z$ is PID)?

Hi I don't know how to show that $\langle 2,x \rangle$ is not principal and the definition of a principal ideal is unclear to me. I need help on this, please.   The ring that I am talking about is $\mathbb{Z}[x]$ so $\langle 2,x \rangle$ refers to $2g(x) + xf(x)$ where $g(x)$, $f(x)$ belongs to $\mathbb{Z}[x]$.


people of serverfault.  Started dabbling in docker with nginx and nodejs, and I'm having a bit of trouble figuring out how to debug my issue here. I'm running 3x nodejs containers and 1x nginx load balancer in front of them.  I can spin up the docker-compose successfully with docker-compose up, but when accessing localhost:8080 I get an nginx 502 with the following error in the console, repeated 3 times (for each node backend):  loadbalancer_1  | 2019/10/05 11:40:31 [error] 6#6: *1 connect() failed (111: Connection refused) while connecting to upstream, client: MY_CLIENT_IP, server: localhost, request: "GET / HTTP/1.1", upstream: "http://172.19.0.4:3000/", host: "MY_PUBLIC_IP:8080"   This is my folder structure:  ├── backend │   ├── Dockerfile │   └── src │       ├── index.js │       └── package-lock.json ├── docker-compose.yml └── load-balancer     ├── Dockerfile     └── nginx.conf   ./docker-compose.yml  version: '3.2' services:   backend1:       build: ./backend       tty: true       volumes:         - './backend/src:/backend-dir-inside-container'    backend2:       build: ./backend       tty: true       volumes:         - './backend/src:/backend-dir-inside-container'    backend3:       build: ./backend       tty: true       volumes:         - './backend/src:/backend-dir-inside-container'    loadbalancer:       build: ./load-balancer       tty: true       links:           - backend1           - backend2           - backend3       ports:           - '8080:8080'  volumes:   backend:   ./backend/Dockerfile  FROM node:boron LABEL Joe Programmer RUN mkdir -p /backend-dir-inside-container WORKDIR /backend-dir-inside-container  FROM node:boron LABEL Joe Programmer RUN mkdir -p /backend-dir-inside-container WORKDIR /backend-dir-inside-container EXPOSE 3000   ./loadbalancer/Dockerfile  FROM nginx LABEL Joe Programmer COPY nginx.conf /etc/nginx/nginx.conf  EXPOSE 8080 CMD ["nginx", "-g", "daemon off;"]   And this is my ./loadbalancer/nginx.conf  events { worker_connections 1024; }  http {   upstream localhost {     server backend1:3000;     server backend2:3000;     server backend3:3000;  }   server {     listen 8080;     server_name localhost;      location / {        proxy_pass http://localhost;        proxy_set_header Host $host;     }   } }   Besides fixing this issue I'm looking to learn what exactly I'm doing wrong here. Thank you for any or all responses.

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


Is there a function in Perl that lists all the files and directories in a directory? I remember that Java has the File.list() to do this? Is there a comparable method in Perl?

How do I get Perl to read the contents of a given directory into an array?   can do it, but is there some method using 'scandir' or a similar term?


I received my copy from a friend, and when I try to upgrade, it keeps saying there is a problem with my Internet connection, but I can access everything online.  Also I can not install anything so please help thank you.   I don't know much about Ubuntu, I just like how stable it is.

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


I have a confusing issue, I delivered the logo to the client with the standard sizes for social media applications (link to the page I took sizes from  ), but he came back and told me that FB size which is 200px*200px looks blurry. I tried it myself and it looked blurry too. Now my question is: are those sizes in this link(In other links too all over the internet) wrong, or there is something that I don't understand?. And if they are correct then why the logo looks blurry? (it looks blurry on all social media sizes). should I only deliver 5000px*5000px version instead of these sizes? (because I tried it and it's very good on all social media apps).

After uploading an image, Facebook converts it to a new image.  Their conversion process introduces artifacts and mottling to the magenta-ish parts of the image.  Original image:   Facebook's conversion:   Are there ways to preserve the original quality of this image and have the image appearance on Facebook reflect more of the original quality?


Can someone help ID a book please. I probably read it in the 80s, but can't be sure it wasn't early 90s. It was the story of a lone human in a mech suit who explores an alien planet where much of the life is crystal based. They smash through everything, overpowering the vegetation in the mechsuit until something unexpected, a laser defence from a plant, immobilises and destroys the suit. They jump out and have to live by their wits. They make friends with an alien community, I can't remember if they're fully sentient. I don't recall how it ends.

I'm looking for a book in which the main character was sent to a prison type planet made of crystal. He wakes up with a symbiotic creature plugged into his ear. The creature is able to communicate through plug in. The creature manufactures new crystal parts for the main character to survive, but does it when he's sleeping; such as changing out his eyes and later internal organs.  Read it in the mid 80's, but I think it was written earlier. Any help on this title would be appreciated. Thanks


I have this bash script:  #!/bin/sh -eux  . ./.env   What does the second line do?   It seems to be impossible to google such syntax :)

I came across this example when trying to mount a usb device inside a openvz container and I have never seen the construct in the second line before. Can you explain what it signifies?  #!/bin/bash . /etc/vz/vz.conf


How to write a whole LaTeX document in bold? I would like to print the pdf in bfseries. Is this possible to achieve by adding some code to the preamble or in the body of the LaTeX document?

I see many posts in how to changes the font and font size, but none for changing the default font for a document to bold font. I believe this is called changing the font series. The approach in  (obtained by random Googling) looks like it should work, but doesn't do anything when I stick it in the preamble. Maybe I'm putting it in the wrong place.  \fontencoding{T1} \fontfamily{garamond} \fontseries{m} \fontshape{it} \fontsize{12}{15} \selectfont   There is also some discussion .


I have the following bash script to increment the assigned date: DATE.   #!/usr/local/bin/bash  DATE=20130625  for i in {1..10} do      NEXT_DATE=$(date +%Y%m%d -d "$DATE + $i day")      echo $i $NEXT_DATE done   However, it is just repeatedly printing today's date as follows.  1 20140122 2 20140122 3 20140122 4 20140122 5 20140122 6 20140122 7 20140122 8 20140122   Any help is appreciated. btw, the OS is Solaris 11. Thanks.

I need to do date arithmetic in Unix shell scripts that I use to control the execution of third party programs.   I'm using a function to increment a day and another to decrement:   IncrementaDia(){ echo $1 | awk ' BEGIN {         diasDelMes[1] = 31         diasDelMes[2] = 28         diasDelMes[3] = 31         diasDelMes[4] = 30         diasDelMes[5] = 31         diasDelMes[6] = 30         diasDelMes[7] = 31         diasDelMes[8] = 31         diasDelMes[9] = 30         diasDelMes[10] = 31         diasDelMes[11] = 30         diasDelMes[12] = 31 } {         anio=substr($1,1,4)         mes=substr($1,5,2)         dia=substr($1,7,2)          if((anio % 4 == 0 && anio % 100 != 0) || anio % 400 == 0)         {                 diasDelMes[2] = 29;         }          if( dia == diasDelMes[int(mes)] ) {                 if( int(mes) == 12 ) {                         anio = anio + 1                         mes = 1                         dia = 1                 } else {                         mes = mes + 1                         dia = 1                 }         } else {                 dia = dia + 1         } } END {         printf("%04d%02d%02d", anio, mes, dia) } ' }  if [ $# -eq 1 ]; then         tomorrow=$1 else         today=$(date +"%Y%m%d")         tomorrow=$(IncrementaDia $hoy) fi   but now I need to do more complex arithmetic.   What it's the best and more compatible way to do this?


A lot of producers these days seem to change the original Japanese name to English alternatives. Why do they do this? Does this add any value to the name of the anime in other countries or is it just that it is easier to read for people outside of japan/otaku society?  Because some of the cases are really weird and in my opinion not necessary. An example of this would be "Ace of Diamond" also known as "Diamond no Ace".  Is there anything to gain from translating the title? Also, why don't all series do this?

Sometimes they change the title into something different, and by different I mean it's not an English translation. An example here is . Although it state that:     Rurouni Kenshin is subtitled "Wandering Samurai" in some English releases.   which makes it the closest translation, as a rough translation of the title would be "Kenshin the Wandering Swordsman". But they also use the name Samurai X for this anime title.     The English-language versions of the OVAs, as well as the film, were originally released as Samurai X in North America, although the original name was included on the later DVD and Blu-ray Disc releases.   But it's not only in North America, as they also mentioned     Sony Pictures Television International created an English-language version of the series, titled Samurai X, that airs outside of the United States   I don't know if there's another anime that also does this, but I've never seen something like this recently.


I have been trying to extract a single value from some HTML data, but I haven't been able to focus on exactly the piece I am looking for: The line I am trying to read from is: 5  There are many other "span" tags with different classes, so I need to only accept "temp" class, and then get the value? I really have no experience with Regex, but have been trying to figure it out. Here are just some of the lines I have tried: //MatchCollection data = Regex.Matches(searchData, @"(.+?)<", RegexOptions.None);  //MatchCollection data = Regex.Matches(searchData, @"\s*(.+?)\s*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @" (.*?)  ", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"(([^<]|<[^\/]|<\/[^s]|<\/s[^p]|<\/sp[^a]|<\/spa[^n]|<\/span[^ \t >])*)", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"\s*([^<])\s*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"\s*(<.*?>) * ([^<] *)\s*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"(?<=<]*>\s*)[^<>]*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"(?<=<]*>\s*)[^<>]*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"(?<=\s*)*", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"] *> (.*?) ", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"", RegexOptions.Singleline);  //MatchCollection data = Regex.Matches(searchData, @"", RegexOptions.Singleline);   Thank you for any assistance you can provide! Doug

I'm looking for a library/method to parse an html file with more html specific features than generic xml parsing libraries.


Assuming $(a,b)=1$, I want to construct an isomorphism $\phi:\Bbb Z_a\times\Bbb Z_b\mapsto\Bbb Z_{a\cdot b}$ defined by $\phi(1,1)=1$. So I need to prove that for any $(x,y)\in \Bbb Z_a\times\Bbb Z_b$ there exists $n\in \Bbb N$ such that $n\equiv x \mod a$ and $n\equiv y\mod b$  For example $(1,2)\in\Bbb Z_2\times\Bbb Z_3$ is $(5\mod2,5\mod3)$  I'm not sure how to prove that, I tried using the Bezout equality...  For the other way we need to assume $\Bbb Z_a\times\Bbb Z_b$ is cyclic i.e. $\Bbb Z_a\times\Bbb Z_b =\langle(x,y)\rangle$  for some $(x,y)$  Since $0\in\langle(x,y)\rangle$, $\exists n\in \Bbb N~:~nx\equiv0\mod a~\text{and } ny\equiv 0\mod b$  And here I'm stuck again.

In general, products of cyclic groups are not cyclic. If $C_n$ is the cyclic group of order $n$, $C_{22} \times C_{33}$ is not cyclic. But is there an easy way to tell when such a product will be cyclic?


I answered a  this morning on bicycles.se, then went to make a small edit to my answer which I reconsidered and cancelled by pressing cancel. I have made no other edits or additions to the page.  As of now on the homepage, it is displaying as 'modified 4 hours ago', by me, not 'answered'. I would like it to say 'answered' so that people think there is something new to be read rather than a (possibly trivial) edit to an existing question.  When I click on the 'modified x hours ago' it takes me to my own unedited answer, but it transpires that another answer was deleted by a mod after I posted mine. This modification has been attributed to me.  It would be better if it said answered by me, or modified by someone else.

In short, if the last action on the post is someone posting an answer, it shows "answered [x] minutes ago PosterName". However, deleting and undeleting a different answer (posted earlier) causes it to switch to "modified [x] minutes ago PosterName", even though post deletion and undeletion do not cause bumping. The last action on the post was answering, so it should continue to show as "answered".  For example, I tested this out in the sandbox:  Answer is posted:        30 seconds later, another answer is deleted (and optionally undeleted; or vice versa probably), changing the label but not bumping it:        The behavior that it should be is:    Find the last active post   If the last active post is deleted it should say "modified" If the last active post is not deleted and not edited it should say "answered" If the last active post was edited, it should say "modified". No duh.      Here's my original bug report, which you can probably just skip unless you need another example:  I just posted an answer to a question, then left the page without doing anything else. But it says the last action on the page is me modifying something, with the  (which shows the last activity) redirecting to , as shown below on the  (it's at the top of the list):    (The , under Questions, also shows this problem.)  I didn't modify the answer after posting (not even during the grace period) nor did I do something else that would cause a "modified" bump (protection, close/reopen votes, add bounty, messing with deletion). There were no deleted answers when this happened. I'm not sure if the problem is related to the question having a bounty on it (by the OP, who is deleted).  None of the other activity on the active page shows this problem. (The "modified 10 minutes ago" on the second question is an edit to an answer.)    Since I first posted this question, another user (named ) posted an answer to the exact same question. For some time the listing read "answered X minutes ago", but now it says "modified X minutes ago" even though it points to the same, unedited answer. However, I noticed that there is now a deleted answer which was last edited before 1006a's answer was posted, but was deleted after it was posted. Now I'm wondering if it has anything to do with deletion.


I'm trying to create a heatmap on a shapefile of numerous points based on a single field in their attribute table. The header of the attribute table is this:  ... and I want to make a heatmap weighted on the "frp" field from the attribute table. However, in the Heatmap (Kernel Density Estimation) settings, I cannot see the "frp" field - only the "longitude" and "latitude" values appear:  What could be wrong here?

I read in a CSV file for linking to a .shp file.   All the variables that are just numbers came in as text.   How do I change the text variables to numeric in QGIS?


I have an application that asks for adminin previleges to run on a user account with standard previleges on a Windows 7 OS. Assuming that there is no way of him knowing the Admin password what would be the best solution to bypass this problem?

I'm want to grant a user administrative rights to one application on Windows 7. I don't want them to be able to have full admin rights, but admin rights are required for one of the applications they need to use.   Is there a way to set up a batch script or something where the user won't know it's being run as admin?  Or is there another way?  How can I accomplish this?


after figuring out, how the linked lists stuff works in C I was just wondering how to correctly allocate a new node.  So lets say my linkedlist is defined with the following struct:  typdef struct NewNode {   int data;   struct node *next; } Node;   Now I'm going to create a new temporary node for whatever reason:  node *temp = (node*) malloc(sizeof(node);   Do I need the cast (node*) or can I as I've seen in couple tutorials leave this without the casting. If not can you tell me what possible errors could occur as my implementation without the casting is completly working.  node *temp = malloc(sizeof(node);

In , someone suggested in a  that I should not cast the result of malloc. i.e., I should do this: int *sieve = malloc(sizeof(int) * length);  rather than: int *sieve = (int *) malloc(sizeof(int) * length);  Why would this be the case?


Note: This is NOT a duplicate of  Difference: In both other questions, the posters traveled once to the US for the original purpose for which the B1 visa was obtained. Their question is about visiting again using the same visa. However, I've not traveled to the US yet, and I'm planning my visit. What I want to understand whether I can use this visa for a visit whose purpose is not the same as what was submitted along with the application.  Can I use a B1/B2 visa for tourism that was originally obtained for business purposes BEFORE I actually visit the US even once? I had applied for a business visitor visa for a valid business reason but by the time I got it stamped, my plan changed. So I've not visited the US even once. Can I now use this visa to visit as a tourist without having used that visa for its original intended purpose? PS: I live in India.

I have a 6-month B1 (business) visa to the USA.   I plan to visit USA for business for 4 weeks (training for my company) and then take 2 week-long vacation to travel around. Of course, you can never be sure if you are allowed into the USA, but theoretically, there should be no issue with the fact that the visit is not solely business, right?  I am afraid that if some further questioning takes place and the security officer sees my business documents confirming only a month's stay with my company, I might be given the permit to stay only for 4 weeks, not at least 6 that I want.   Sorry if it was answered before, but I searched and most questions are about B1/B2 visa (). When applying for a visa in my country I also discovered that slight differences in phrasing the travel purpose ("working" instead of "internal company training") can result in not getting a B1/B2 but B1 for a shorter period instead (but maybe I am paranoid).


I've noticed that when writing a shell script, there's a lot of inconsistency in whether people put a space after the I/O redirection operators. For example:  foo >bar.txt   Will work, but so will this:  foo > bar.txt   ....and even this:  foo       >             bar.txt   In fact, even  is frustratingly inconsistent about it - using 2>&1 (which doesn't actually work in my Bash terminal with spaces) in one place and > filename in another!  I've always used the former, as the latter feels like 2 different arguments to me, but I was wondering: Is there any difference or reasoning between the two?  Is >bar.txt more portable than > bar.txt or something? Or should I use 1 syntax in 1 defined situation, and the other in another?

I'm paranoid about this, but hopefully it's a simple question:  Is there any difference between  cat file1 | egrep -oP "[Mm]y string" > /home/user/file.txt   and  cat file1|egrep -oP "[Mm]y string">/home/user/file.txt   i.e., does it matter if I have spaces padding the pipe (|) and redirection (>) characters? I'm really paranoid that having spaces there the spaces will somehow end up in the output file when I don't want that. Can anyone clarify? (Using Ubuntu 12/bash if that matters.)


Everyone keeps telling me its just 10.3 minutes and no one knows how to get that number form theory. Any idea?

A neutron outside the nucleus lives for about 15 minutes and decays mainly through weak decays (beta decay). Many other weakly decaying particles decay with lifetimes between $10^{-10}$ and $10^{-12}$ seconds, which is consistent with $\alpha_W \simeq 10^{-6}$.  Why does the neutron lives so much longer than the others?


I want to put a wedge above a character, like a tilde can place, over an "S" or a "K".  The MWE:  \begin{equation} \begin{split} K_{ij}=\^{K}_{i,(1+j-i)} \qquad \text{para} \qquad i & =1,2,...,\text{NGDL};\\ j & = i,i+1,...,\text{SAB}+i \leq \text{NGDL}\\  \end{split} \end{equation}   The K shows without the chevron.

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


Prove: for any set $A, \ 2^{|A|} \neq \aleph _{0}$  as $\aleph_{0} = |\mathbb{N}|$.   my attempt:   Suppose by contradiction that there exist a set $A$ such that $2^{|A|} = \aleph_{0}$, which Implies that $|P(A)| = \aleph_{0}$, using .   meaning, intuitively that $ \aleph_{0}  > |A| = \log_{2}(\aleph_{0})$, thus $A$ is finite.   at this point I'm trying to understand why the fact that $A$ is finite means that $P(A)$ also must be finite, which is the core of the argument.   there's no need to prove that $2^{|A|} = \mathfrak{c}$, but only to prove that there exist no set $A$ such that $2^{|A|} = \aleph_{0}$

Is it consistent with ZF for there to exist a set $S$ such that the power set $P(S)$ is countable? If so, what is the weakest form of the axiom of choice needed to prove that no such set exists?


Let $K$ be a number field and let $\mathcal O_K$ be its ring of integers. Let $I$ be a non-zero ideal in $\mathcal O_K$.      If $I$ is free as a $\mathcal O_K$-module then is it a principal ideal?    I know that any (fractional) $\mathcal O_K$-ideal is generated by at most two elements since $\mathcal O_K$ is Dedekind but is there an easy way to show the above?   Many thanks.

Let $R$ be a commutative ring and $I$ be an ideal of $R$. Is it true that $I$ is a principal ideal if and only if $I$ is a free $R$-module?