I work on a ship and I will disembark in Cozumel, Mexico.  Can I stay for a vacation in Mexico with my C1/D visa?  I hold a Serbian passport.


Do you know about any good photo / 3D references sites?  I want to create a 3D human models but I need good references for it. Do you know about any free or paid site that you trust? Thanks


How to dynamically update a postgres sequence starting value?

I need to re-start some postgres sequences to start at number greater than the current value in that field. I'm trying to do something like this.... psql -U <myowner> -d <mydatabase> -c "ALTER SEQUENCE <mysequence> RESTART WITH (SELECT max(field1) FROM table1); "  The RESTART WITH clause seems to prefer something hardcoded so it seems I have to run the SELECT max() bit and then edit my original attempt with the number returned. like this. psql -U <myowner> -d <mydatabase>-c "ALTER SEQUENCE <mysequence> RESTART WITH 123456789 ; "  I need to do this quite a lot, is it possible to get the first method to work?


What is the limit of cabin baggage on Wizz Air flights?

What's the weight limit on Wizz Air, for cabin baggage?    I can't find anything about the weight on their website. I know that for Ryanair is 10kg, and EasyJet say they don't have a limit for weight.


Comma - American versus British, Really?

So, from my writing infancy, my High School Teacher Mom taught me never to place a comma before the conjunction in any list of more than 2 things and yet there seems to be quite some debate about it, at least now.  From what I've learned, according to the APA, MLA and Chicago MoS, my immediately preceding list is grammatically incorrect (at least for American writing).  However, according to the AP, it is correct.  Have these largely considered worthy sources of grammatical information (and the like) always been in discord over this matter?  And regardless, wouldn't it be acceptable to choose either format?  I certainly hope so, as I far prefer writing lists without the comma before the conjunction to the alternative.


How can an object move faster after leaving the gravity of a planet, should a gain in potential energy by moving away from the planet lead to a loss of kinetic energy? Or am I missing something essential like the a change in angular momentum of some body?  My question is similar to this question but I wish to discuss the more technical aspects.


Android is a kind of Linux. So I would be able to use the commands.  Can I use Linux commands on Android? If I can, how do I?


Me and my friend don't play on realms, but we can join each others world on Minecraft Pocket edition. The thing is he can always easily access my world, but sometimes I can't always get on his world. It's odd actually, once when I was trying to join his world the screen just went blank.  Instead of loading the server/world, where is the dirt background and it writes "locating server" on it but, it didn't show the "locating server". It just displayed the dirt background. Then it said: "unable to connect to world". Even though we both have the same version of Minecraft Pocket edition. My question is: How come I can't join his world?


Newbe Ubuntu installer - Ubuntu 14.04.3 LTS 64bit - Windows 10

Having some issues installing Ubuntu 14.04.3 LTS 64bit next to Windows 10.  This is what I did:  1) Created a bootable usb with ubuntu on it using Universal-USB-Installer-1.9.6.3  2) Changed the boot mode  3) Boot from USB - It showed the option to test drive or install - I chose install  4) Choose Language  5) Setup Wireless - I didn't choose anything here  6) Then it showed me the preparing to install  7) After that a message popped up saying:      Unmount partitions that are in use The installer has detected that the following discs have mounted partitions /dev/scd Do you want the   installer to try and unmount these partitions before continuing? If   you leave them mounted, you will not be able to create, delete, resize   partitions on these discs, but you may be able to install on an   existing partition there.   So obviously I said yes.  8) Installation type - I chose something else - This looked nothing like the screen shots I saw on the installation guide.    9) Then it only gave me the option to choose my bootable usb for the installation. With a bunch of options to choose, so I got scared and quit.     Can any one please help?  Keep in my mind I do not know a lot, so please dumb it down. Why can't I choose to run it along side Windows 10? Why doesn't the installation pick up my hard drives?  If you need any other info, please ask. But I think I put everything in here.


Issue with proof in Statistical Theory related to Beta and Binomial distributions

Assume $X_n$ is distributed $\text{Beta}(1/n, 1/n)$ and $X$ is distributed as $\text{Binom}(1,1/2)$. Show that $X_n$ converges to $X$ in distribution.  I'm having some issue with this question. I understand that if I want to show that if $X_n$ converges to $X$ in distribution then $F(X_n) \rightarrow F(x)$. This is for their cumulative distribution functions. However, I'm a bit stuck on how exactly to go about this.


vim editor creates additional file having "~" after the end of file name

Hi I have followed the vimtutor and finished it. After that when I am using vim editor it create backup file as follows  filename.xxx~   does any one know why its create that file and how can I stop that.


Could there be a list of checkboxes to single out which information to update when copying profile info to linked accounts?  For example, if you had moved and only wanted to update your location information, you wouldn't want to destroy custom display names and custom profiles on various sites.  It could be hidden behind some "advanced copying" button, or the default is to tick every checkbox, so the basic functionality is still there.  I've just accepted that more detailed site-specific profiles are just too much work, but I do keep an extra blurb about code on SO (my most active SE site).  Today I decided to sync my other profiles (without that irrelevant blurb copied when they were created).  I forgot it copied display names, so I lost my Meta name for a month (I love that feature delay).  Regardless of display name, since you can change the other information manually without delay, if this was easier, wouldn't it encourage more detailed and site-relevant bios?    I am mostly focusing on the bio part of the profile page here (rather than the display names, even though I like that too), because I think site-specific bios can be very useful if you can use them easily.  I've not even considered it, except for SO and Meta, because it would be so much manual work too easily wiped out (as I've done now for Meta); surely others would start to use them if it was easier?  Instead of the above solution, could there be a "locked" checkbox when editing a profile (and hence seen when changing a bio to be site specific), so that particular bio isn't updated when copying profile information?


Find the sum of this series.   I tried writing the general term of this term. I succeeded in it but the sum inside the bracket depends on r which makes more problem to get overall sum.  I know that this uses the concept of  binomial theorem and binomial coefficients but I am not able to break through it to get the desired concept to use.


consider there a directory called hello world in the current directory. Yes the directory has a space in it. For sake of example lets say it has a file called f1.txt.  ls 'hello world'   will print  f1.txt   but  a="ls 'hello world'" $a   say  ls: cannot access ''\''hello': No such file or directory ls: cannot access 'world'\''': No such file or directory   So the question is how to make ls list the directory hello world. Basically how to this  a="1 2" b="ls $a" $b   to actually list the contents of the folderhello world  PS: I don't want to do  a="1 2" ls $a   I want to store it and only then run it


If $\gcd(a, b) = 1$, then $\gcd(ab, c) = \gcd(a, c) \cdot\gcd(b, c)$

How can I prove that if $\gcd(a, b) = 1$, then $\gcd(ab, c) = \gcd(a, c) \times \gcd(b, c)$?  By eea there exists $ax+by=1$ from $\gcd(a,b)=1$ so a and be are co-primes there also exists $dk=a$ and $dj= b$ where $d=\gcd(a,b)=1$ this is all the information I have gathered from the question but I dont know how to approach and solve it. Can anyone help explain to me how to arrive at the answer? Thanks!


Why does my code only produce a 0.000000 outcome?

Here is the code I'm using,  #include <stdio.h> int main () {     /* variable definition: */     double sidea, sideb, sidec;     /* Prompt user for side a */     printf("Enter length of side a of the triangle: \n"); // Input the base     scanf("%f", &sidea);     /* Prompt user for side b */     printf("Enter the length of side b of the triangle: \n"); // Input the base     scanf("%f", &sideb);     /* Prompt user for side c */     printf("Enter the length of side c of the triangle \n");     scanf("%f", &sidec);     // Calculate the Perimeter     double perimeter=  (sidea + sideb + sidec);     // Print the result     printf("The perimeter is : %f \n", perimeter);     return 0; }   Input data: 4.6 7.5 5.8  I can't for the life of me figure out why any values used for input result in 0.000000. Using float seems to work just fine. What am I missing. Thanks!


Symmetrical perspective with Free Transform in Illustrator CS5?

In Adobe Illustrator CS5:   I want a "depth effect" to an object with the straight-from-the-front perspective. But with the Free Transform-tool it seems to only be possible to drag one corner each time to the middle which makes it very hard to get it symmetrical.   Is there any way to get it symmetrical?    Edit:  I've tired to place a centred rectangle to have something to snap to. But it turns out that when I drag the other corner, the first corner then change position:


We all have heard this proverb in Urdu and Hindi      धोबी का कुत्ता न घर का न घाट का   Literal translation      The dog of the washerman belongs to neither the riverbank nor the house    An alternative:     The dog that runs after two bones, catches neither   The original Hindi proverb suggests the idea if someone comments on you      धोबी का कुत्ता न घर का न घाट का   They mean to say you are caught between two things because you do not belong to either of two things, or because you try to do two different things and fails at both.  This proverb was used by Mirza Saud who was a renowned Urdu poet, for Mirza Mazhar Jaan-e-Janaan's poetry as a scorn. Mirza Mazhar was a renowned poet of Persian. He later on did some stupendous and chromatic poetry in Urdu as well, however, initially he was not very comfortable in Urdu poetry.  His instructor advised him to start poetry in Urdu instead of Persian as the days of Persian poetry in India were numbered in his view. Mirza Mazhar's initial experiment in Urdu poetry was a disaster. The Urdu poets of his time did not take his arrival in their domain with joy. He was barraged by insult and one such poetic insult became proverbial:   [cut off by OP]


Do out parameters in C# have any performance implications I should know about? (Like exceptions)  I mean, is it a good idea to have a method with an out parameter in a loop that will run a couple of million times a second?  I know it's ugly but I am using it the same way as Int32.TryParse is using them - returning a bool to tell if some validation was successful and having an out parameter containing some additional data if it was successful.


Let $R$ be the ring of all functions $f:\mathbb{R}\rightarrow \mathbb{R}$ with the operations $$(f + g)(x) = f(x) + g(x)$$ $$(fg)(x) = f(x)g(x)$$ Let $c ∈ \mathbb{R}$. Show that $J = \{f ∈ R | f(c) = 0\}$ is a maximal ideal.Can you give me some hints ?


Can a probability distribution value exceeding 1 be OK?

On the , there is this line:      $p(\mathrm{height}|\mathrm{male}) = 1.5789$ (A probability distribution over 1 is OK. It is the area under the bell curve that is equal to 1.)    How can a value $>1$ be OK? I thought all probability values were expressed in the range $0 \leq p \leq 1$. Furthermore, given that it is possible to have such a value, how is that value obtained in the example shown on the page?


One-sided limits of $f'(x)$ at a point vs. one-sided limits of the difference quotient at that point

I know that if a function is piecewise, then when differentiating it one needs to deal separately with the points of intersection of the pieces, because the derivative may not be defined there.  Also, if a one-sided limit of $f'(x)$ at these "crucial points" is infinite or doesn't exist, it doesn't preclude the limit of the difference quotient from existing and being finite. For example, take $f(x)=x^2\sin\frac1x, f(0)=0$: $f'(x)= 2x\sin\frac1x-\sin\frac1x $ has no limit as $x\to0$ but $\lim\limits_{h\to0}\frac{f(h)-f(0)}{h}=0=f'(0)$.  On the contrary, looking at $f(x)=\sin x +\lvert \sin x\rvert $ on $[0,2\pi]$ one has $f'(x)=2\cos x$ on $(0,\pi) $ and $f'(x)=0$ on $(\pi,2\pi)$ so $\lim\limits_{h\to0^+}f'(\pi+h)\ne\lim\limits_{h\to0^-}f'(\pi+h)$, but they are both finite. And in this case it's easy to find that they agree with the one-sided limits of the difference quotient. Why? Does the finiteness of the former imply that they agree with the latter? Is this also true if the one-sided limits of $f'$ at the crucial points agree with each other?


Does the Ring of Mind Shielding magic item or the Mind Blank spell block the Dream spell? If not, what does?

Does the ring of mind shielding magic item or the mind blank spell block the dream spell? What spells and/or effects (apart from not sleeping) give someone immunity from being contacted with the dream spell?  It would seem to me that as long as you're on the same plane as your target and your target is asleep, there is no RAW way for your target to avoid being targeted by dream.


What's the difference between space and time?

I'm having a hard time understanding how changing space means changing time. In books I've read people are saying "space and time" or "" but never explain what the difference is between the two concepts or how they are related.  How are the concepts of space, time, and space-time related?


I need help with finding the area of the largest rectangle in an ellipse from $y^2 + (x^2)/4 = 1$.  I got it to y = $\sqrt{ 1 - (x^2)/4}$ but then I don't really know what to do, please help.


comparing Pearson Correlation of 2 samples against a rating sample set

I am analyzing a survey result. I have 2 factors 1) a trainer factor 2) a participant benefited factor. These 2 factors are compared against a training rating and correlation is calculated. can i compare the (r)s? i.e., (r) of trainer factor to rating and (r) of participant factor to rating


Submitting non-interactive jobs over ssh

I have SSH remote access to a machine I'd like to use for long-running jobs. What I currently do is simply   ssh user@remote command-to-run   This has several drawbacks:   I can't simply suspend my local machine - when I do that, SIGHUP will be sent to the remote process, effectively killing it. I could use nohup to prevent that. The output may be long, I'd rather have it redirected to files. Of course, I can do it manually, but it gets clumsy with a series of commands. The process may run a really long time. It would be ideal that the submitting program only confirms that the command (script) has been successfully submitted and terminates. I'd like to get a mail notification, when the process terminates, with its exitcode. Of course, I could use a shell script and a terminal command to send it manually, one more hack. I want to be able to schedule multiple scripts at once safely. In particular, I want to be able to push multiple scripts with the same name without manual renaming. I don't want to worry about possible files which already exist on the file system.   This is very similar to what SLURM does, but I don't have any administrative rights on the remote side. Besides, when I have the access to all cores of the remote machine, it makes no sense to declare, how many cores I need.  Is there anything I could use for this? What I described seems like a common usecase.


C# update UI from different class/thread

Good morning guys, I'm trying to write some application in C#, where I like to update the UI (A progress bar in this case) from another thread and class.  But I just can't get it to work, I googled and search around but I'm afraid I just don't get it. I have a windows form application, I start a thread when I click a button, and somewhere in this thread I would like to update my UI.  I either get: An object reference is required for the non-static field, method, or property or something in the direction of the object being created by a different thread.  (At the location where I try to call Form1.UpdateProgressBar(value); in fileReader).  I have no experience in object orienting programming, I usually stick with C. If anyone could tell me the right way to do this, I would be very happy.  Edit_1: Alright.. Combinations of errors, the answer so far might have helped if I didn't have he static issue. And fixing the static issue by making the entire class static creates another X amount of errors on its own, including:  Static classes cannot have instance constructors    namespace TestCode {    public partial class Form1 : Form   {     static fileReader SourceReader;     public Thread SearchThread { get; set; }      public Form1()     {         InitializeComponent();      }      private void button1_Click(object sender, EventArgs e)     {         folderBrowserDialog1.ShowDialog();         Console.WriteLine(folderBrowserDialog1.SelectedPath);          this.SearchThread = new Thread(new ThreadStart(this.ThreadProcSafe));         this.SearchThread.Start();     }       public void UpdateProgressBar( int value)     {         progressBar1.Value =value;      }      private void ThreadProcSafe()     {         SourceReader = new fileReader(folderBrowserDialog1.SelectedPath);     }   } }   Class 2:       namespace TestCode      {          class fileReader          {               public fileReader(String path)              {                 int value = 20;                 /*Do some stuff*/                   Form1.UpdateProgressBar(value);               }            }       }


C++ Changing a struct variable from a member function

I am trying to update a variable in a struct, from a function. It is compiling fine but is not changing the value. I am using the Arduino framework and have the following header myLib.h  #include "Arduino.h" class gaugeClass{   public:     byte devAddr;     template<typename T>     void readReg( T dataParam ){       dataParam.val = 0x07;     }     struct Flasht{       struct Thresholdt{         byte val = 0x01;       } threshold;     } ; };   with an instantiation of the struct in myLib.cpp  #include "myLib.h" gaugeClass::Flasht myData;   Then in my main code, I call the readReg function  #include "Arduino.h" #include "myLib.h"  gaugeClass myLib; extern gaugeClass::Flasht myData;  void setup(){   Serial.begin( 115200 );   Serial.println( myData.threshold.val, HEX ); //this reads 01   myLib.readReg( myData.threshold );   Serial.println( myData.threshold.val, HEX ); //this also reads 01 }  void loop(){}   I want the readReg function to update the value in the struct in the myData instance, but it is not doing it. I can correctly read the value of myData.threshold.val from the readReg function, but I cannot write to it. Any help appreciated Thanks


Proof of $\sum_{k=1}^n \binom{n}{k} \binom{n}{n+1-k} = \binom{2n}{n+1}$ via induction

I'm having trouble to prove the following formula using Induction on $n \in \mathbb{N}$: $$\sum_{k=1}^n \binom{n}{k} \binom{n}{n+1-k} = \binom{2n}{n+1}.$$ I've tried all the usual identities, but they seem to lead nowhere. Is there any trick to this, or is it just not possible to prove this using induction?  I'm thankful for any tip or advice on how to approach this :)


Is there any isomorphism between the non-zero complex numbers under multiplication and the complex numbers under addition?

It seems like there is no trivial isomorphism between them and both are abelian and non-cyclic, so, it makes it even harder to conclude anything. I need some hints.  If I had to make a guess, I'd probably say there is no isomorphism between them.


How to uninstall Amazon app in 17.10, 18.04?

I do not particularly appreciate the Amazon logo reminding me to consume every time I open the app overview in Ubuntu 17.10 and later?  Since previous questions have been related to the Amazon launcher of the 17.10-irrelevant Unity-specific unity-webapps-common package, the answers are no longer applicable.  How may I in uninstall the app Ubuntu 17.10 running GNOME Shell?


“Can” vs “Able to”: People/Animals vs. Inanimate Objects

I’m wondering if the English grammar “rule” given below, which I have heard from numerous non-native speakers, has any validity.      “can” is used for people, animals, and inanimate objects.       “able to” is　not used for inanimate objects, only for people and animals (animate objects).    Is this an accurate description of current usage? Was it maybe a prescriptive rule from long ago?  Just a quick Google search for “is able to” and “science” shows the following, and all from prestigious publications or institutions:     In this situation the neuron is able to form new connections.      The material is able to store the gas at a much higher concentration      The human brain is able to recognise a familiar object      The enzyme is able to go on chewing up      The new compound, Pentobra, is able to easily punch holes


I'm having some problems with MLA style citation with Biblatex. I have tried to implement the example in a newly created document,   \usepackage[american]{babel}  \usepackage{csquotes}  \usepackage[style=mla]{biblatex}  \addbibresource{<bibfile.bib>}   and used \autocite{x} and \printbibliography between the \begin{Document} \end{Document}  Found here:   And I have also copied this example (the correct answer):    But I have got a bunch of errors...  I was able to cite with biblatex APA style with Biber. I am using TeXstudio, but I have also tried running the commands in cmd. (I'm using Windows 10). The default bib tool is configured to Biber. I have TeX Live (2015) on my computer, with full install.  I am getting these errors:   Thank you for your time, attention, and for your answers in advance.


Mac OS X 10.6 executable not found without full path

I just installed Apache via MacPorts. It seems that my Mac was absolutely confused about which version of the Apache executables to run.  After moving the Apache executables that ship with the Mac to a directory that is not listed in the PATH variable, trying to run the httpd built by MacPorts fails even though the correct directory (/opt/local/apache2/bin) is listed in the PATH variable.  If I navigate to the directory /opt/local/apache2/bin and type the command httpd I still get the error message     -bash: httpd: command not found   If I type the command with the full path /opt/local/apache2/bin/httpd it works fine.  I've run the command alias to see if something was clashing but the only thing listed is:  alias wget='curl -O'   How do I find what is intercepting the command and preventing the executable being found in the directory, even when I'm inside the same directory?  By the way, the httpd file is executable:  -rwxr-xr-x  1 root      admin  442496  9 May  2012 httpd


Say I have a function $f(x)$ on some interval $[a,b]$.  Say it is integrable such that $\displaystyle\int f(x)~dx $ is defined.  Is $\displaystyle\int f(x)~dx $ necessarily continuous?  If I were to know that the integral is integrable itself such that $\displaystyle\int \int f(x)~dx $ is defined. Would that change anything?   If so why?  Thank you


Can we change our profile info like profile picture and name and if yes than how can we do so?  Can anyone help?


What is Every Single Command in Minecraft

I would like to know how what the commands in minecraft are that includes cheats.  The help command does not state every command.


Nikon B700 bridge camera vs Canon 1300D DSLR for beginner?

I have been doing photography with my mobile camera. I want to step up to the next level. I am confused between Nikon B700 (bridge camera) which has really good features and 60x zoom and Canon 1300d (DSLR). I want to cover most types of photography.


It is based on set theory. Here I wan to know that how can I derive the modulus of P(A) is equal to 2ⁿ.

How to proof /P(A)/=2ⁿ / / For modulus sign A: Given set P(A):Power of set A 2ⁿ: The number of possible elements. Hints: In the question it says that to prove it by induction method .  /P(A)/=2ⁿ is possible when set A has 'n' number of elements.


Let $K$ be a field. Then how to show that all powers of the prime ideals $p_i=(x_1,\ldots,x_i)$ $(i=1,\ldots,n)$ are primary ideals in $K[x_1, \ldots,x_n]$ ?   It is easy when $i=n,$ but if $i<n$ how can I approach ? Any help will be appreciated. Thanks.


Running in a VM. How can I access the host computer's files?

I'm running Ubuntu in a VM, which is running on a Win7 host.  How can I access the host computer's files?


"Show desktop" keyboard shortcut in Mac OS X

I am using a MacBook Pro with Mac OS X 10.5. Is there a similar function to "show desktop" (shortcut is WIN+D) on a Mac?   It should hide all applications and show a clean desktop.


Change the default text and style for input type='file'

I have an input of type file. 'Choose File' will be displayed on the button and beside it, 'No file chosen' will be displayed. But i want to change the button color and text of the button.    <form action="demo_form.asp">   Select a file: <input type="file" name="img" class='customBtn'>   <input type="submit"/> </form>   I tried adding some css  .customBtn input[type='file'] {   color:#f00 }   Can some one help me on this?


Balloon Simulation - String is floating like balloon

I'm trying to simulate balloons gathering under a tent. I've finally figured out the stiffness and gravity of the balloon using a combo of soft body and rigid body modifiers, but the string is now the only issue.   (View from bottom looking up)   The string just continues to gather at the top instead of hang down. How do I make the balloon have negative gravity, and the string have positive gravity? Or.. is there another solution for it to remain hanging down?  The eventual goal is to add maybe 50 balloons to the scene to have them fill the tent with their strings hanging down.


Bypass GPG signature checks only for a single repository

I have read the following article:   It outlines how to configure apt to not check the signatures of packages at all.  However, I'd like to limit the effect of this setting to a single (in this case locally hosted) repository.  That is: all official repositories should use the GPG signature check as usual, except for the local repo.  How would I go about doing that?  Failing that, what would be the advantage (security-wise) of signing the packages during an automated build (some meta-packages and a few programs) and then doing all that  prescribes? After all the host with the repo would then also be the one on which the secret GPG key resides.


Prove or disprove: if $y'=y-y^2$ and $y(0)=a$ where $00$

Prove or disprove: if $y'=y-y^2$ and $y(0)=a$ where $0<a<1$ then $a<y(x)\leq 1$ for any $x>0$.   I thought about using PL and Grownwall, but this led me to nothing.


Help needed for a proof involving the gcd of $3$ integers

The question that got my stuck is as follows: Prove that for all integers $a, b, c,$ $\gcd(a, b, c) = \gcd(\gcd(a, b), c)$. I have no idea on how to start or how to express $\gcd(a, b, c)$ into equations, please help, thank you.


Missing tag descriptions on random tags in tags page

In the tags page, the description and question count of some tags are missing. This also happens when these tags are searched. They seem to be random.  Is this a bug or an intended feature?


Convergence of the series $ \sum_{n=1}^{+ \infty } \frac{1}{n \cdot \ln(n) \cdot (\ln(\ln(n)))^{a}} $

I have a problem with a convergence of the series $ \sum_{n=1}^{+ \infty } \frac{1}{n \cdot \ln(n) \cdot (\ln(\ln(n)))^{a}}$ depending on the parameter $a$. I know that  $\frac{1}{n} \rightarrow 0$, $\frac{1}{\ln(n)} \rightarrow 0$, but I don't know how to deal with $\frac{1}{\ln(\ln(n)))^{a}}$ and how to get to the final answer. So far I solved tasks with  $\frac{1}{n ^{a}}$ and I know that $a>1  \Leftrightarrow \sum_{n=1}^{+ \infty }\frac{1}{n ^{a}}$ is convergent, but in this task I cannot use it. Can you help me?


I just uploaded an image on Desktop site using smartphone (Android). Why don't you simplify everything to add image upload on mobile site?


Seeking administrative divisions shapefile for Italy?

I am looking for administrative divisions' shapefile for Italy for QGIS. I found one which is a bit old with some inconsistencies.   Can anyone please suggest a database to find better (or newer) shapefiles?


How can I identify duplicate image files?

Over the years, I've accumulated a lot of pictures, across a bunch of different machines.  I think I've mostly kept them in a yyyy/mm/ directory structure, but especially with some of the older pictures, there seem to be a lot of duplicates.  What's the best way to identify the duplicates?  Are there good tools to do this, or am I going to have to write something on my own?


$$3x^3 + 2x^2 +75x -50 = 0$$ Solve for $x$ I've tried to solve this cubic by factoring, but it doesn't factor. Factoring by grouping doesn't work, and using the factor theorem also doesn't work. How would one go about finding the root/s in a situation like this? I've plugged the equation into a couple of online calculators, they give the roots, but don't explain how they got their results. I have little experience with cubic equations, and I would like to know how you can solve this particular one.


Remove files/folders that start with "."

This command:  rm -rf "$HOME/.quicklock/locks/"*   does seem to remove files or folders in the locks directory, which start with "."  how can I remove those files too? Any other filenames that would fail to be removed given that command?


Best way to forward whole ipv6 /64 subnet range to single address (on Linux, obv)?

I want to forward incoming connections to any address within an assigned ipv6 /64 subnet on a VPS.  Obviously I can't add a billion individual address to the interface, but perhaps I could use a bogus route with a mangle iptables rule to pretend 1 address is a router for the subnet, then just answer arriving packets instead of forwarding them on? Not sure if that's possible or if there's a cleaner approach.


What is the command to minimize the gnome terminal?

How can I minimize the Terminal window using a command? For example: I use the clear command to clear the terminal output, which command can I have to use to minimize the terminal window?


Trying to understand the true meaning of integral and Derivative in calculus

I'm solving a physics question, and i just encountered some question i had no idea how to start, i just got the right answer and inside it it has something in math i never thought possible,  I know that the integral of $a$ (acceleration) by $t$ (time) will give me $v$ (velocity), I also know that the integral of $v$ by $t$ will give me $r$ or $x$ (the movement vector). I know that the derivative of $x$ will give me $v$, and the derivative of $v$ will give me $a$.  I just saw these few lines:    I somehow understand that you can replace $a$ with dv/dt because it's basically the same, but i have no idea how you can multiply the dt in the left sector of the equation, what does it mean?  I always thought that dx is basically saying 'Derivative by x' i never thought it's something "real" you can actually multiply and use basic math with...  Hope you could give me some idea about it, thanks!  In other answer i found this as the answer to "What does $dx$ mean?":     $dx$ does not mean anything. It's just a syntactical device to tell you the variable to differentiate with respect to or the integration variable.   This is exactly why i'm asking, because how can you multiply $dx$ in another thing if it's only a syntactical device?


Are first passage times in a Brownian motion the same as the ARL in a CUSUM?

I am investigating a link between a random walk with drift (call it Brownian process or difusion with drift) and the CUSUM statistic. The CUSUM procedure accumulates deviations from the process mean over time, thus, if a change in the mean occurs for some reason, then the CUSUM will steadely increase over time, eventually crossing some pre-determined control limit when an alarm is raised.   Can anybody enlighten me as to whether this is in any way similar to calculating the first passage time for the CUSUM, that is the time it takes to cross a given barrier. Is the CUSUM ARL the inverse of the probability of crossing this barrier? How do I go about calculating this probability?   ...so many questions!! Any thoughts are appreciated!!


How can I have a "show desktop" icon when scrolling through opened applications using Alt+Tab in 18.04?

I want to see a "show desktop" icon when I press Alt+Tab (i.e. in the Application-switcher).  My question is the opposite of   I am using Ubuntu 18.04.    I have installed GNOME Tweak Tool which I think may help, but I don't know how to achieve what I want.


Is there a way to bring a Trello card back automatically from the archive on a due date?

Probably not with Trello, but maybe with some integration.  What I need is a solution for archiving cards because I'm not going to work with them now, but later they would come back, so I would remember doing what should be done.  Something in the lines of some email "follow up" services out there that help you remind things and at the same time keep your inbox clean.


What techniques, tricks or otherwise have you used to get upgrades on flights?

I've travelled a lot.  Living in New Zealand or the UK means anywhere is likely a flight, but I've always flown economy.  Twice between LA and Auckland I managed to get the exit row after talking nicely to the check-in girl, but apart from that, nothing.  I've spoken to ticket agents, tried 'check in chicken' (where you wait until the last minute before checking in, hoping there's an overbooking of economy) but have never managed to get an upgrade, while others I know seemingly get them quite often.  What strategy have you used or do you suggest to achieve this?  My next flight is from Melbourne to Tokyo, and I plan on trying all of these ;)  (Related questions on  and  upgrades)


Embed Google Spreadsheet in Google Document

Is it possible to embed a Google Spreadsheet into a Google Document à la Microsoft Excel and Microsoft Word? How about a chart from a Spreadsheet?


Describe a fallacious opinion regarding one's own ability

What's a phrase that describes a unfounded tendency of a person to think that he or she is smarter or possesses more skill than average in a competitive environment such as the stock market or say, the casino, and as a consequence is entitled to great financial gain at the expense of others, although the same belief is more likely to instead cause him/her to lose badly?


"sudo -u postgres psql postgres" does not ask for password

I've taken over a system using postgres. When logging in, if I use ...  sudo -u postgres psql postgres   ...it does NOT ask for a password. However, if I do ...  psql -U postgres -h localhost postgres   ... it asks for the password.   Why?  How is this difference configured? Can it be configured for a different user to login this way?  (NOTE: user postgres is NOT in the sudoers file, or in the sudo group.


How can I calculate the possible ways from point A to point B on a empty 8x8 chessboard while only being allowed to move up and right.  Lets say I have to travel from x1 = 1, y1 = 1 to  x2 = 2, y2 = 2  Then there are 2 possible ways.  But what about x1 = 1, y1 = 1 to  x2 = 8, y2 = 8  Is there some sort of a formula? Something with vectors?


Multiple armor pieces not giving stacked bars?

As relating to  I am now running into a different error. I have 2 pieces of diamond gear that each provide 3 bars of armor, but when both worn they will only provide 3. If EITHER ONE is worn by itself it will provide it's respective 3 bars but together only 3 bars show up. Is there another tag that I am missing?  Commands:  /replaceitem entity @p slot.armor.head diamond_helmet 1 0 {display:{Name:"Tank Helmet",Lore:["You feel slower, but protected"]},AttributeModifiers:[{AttributeName:"generic.armor",Name:"armor",Slot:"head",Amount:3.0,Operation:0,UUIDMost:1,UUIDLeast:1},{AttributeName:"generic.movementSpeed",Name:"generic.movementSpeed",Amount:-0.05,Operation:0,UUIDMost:66122,UUIDLeast:55689}],ench:[{id:0,lvl:1}],Unbreakable:1}  /replaceitem entity @p slot.armor.feet diamond_boots 1 0 {display:{Name:"Tank Boots",Lore:["You feel stronger, and protected"]},AttributeModifiers:[{AttributeName:"generic.armor",Name:"armor",Slot:"feet",Amount:3.0,Operation:0,UUIDMost:1,UUIDLeast:1},{AttributeName:"generic.attackDamage",Name:"generic.attackDamage",Amount:1,Operation:0,UUIDMost:101245,UUIDLeast:5744789}],ench:[{id:0,lvl:1}],Unbreakable:1}


recover partitions lost during installation

I installed Ubuntu 13.04 over my Ubuntu 12.04 installation. I had divided my hard drive into three partitions but when I reinstalled without formatting the disk, it made a single partition and I lost all my data.  Is any way to recover my data?


Confused about gravitational potential energy

So learning the concept of gravitational potential energy, my professor says that when lifting an object without any acceleration, the force we exert on the object to lift it is the same as the force of gravity pulling it down. For some reason my mind is having trouble understanding that.   If the force pushing up on it is the same as the force pushing down on it, then how can we be lifting the object?   I understand that we want it to have no velocity so that none of the energy is converted into kinetic energy and so that we only have potential energy and that's how we come up with $mgh$. I just don't understand how we are able to lift the object to give it the potential energy in the first place if the net force is zero?


When / how is credit card interest charged?

I'm currently a student in college in the United States. I have a scholarship, and I work, so I'm in the fortunate position of earning more money than I'm spending. I have a credit card, but pretty much the only reason I have it is to build up a credit history.   If I make multiple payments on my credit card throughout the month, each time paying the balance in full, will the card company charge interest if there happens to be money on the balance on whichever day they charge interest? Is this strategy good for my credit score?


Sponsor Gallery, Page, or Something Like That?

nhj asked the other day,  In , I wrote:     We were thinking of putting together a "sponsor gallery" of sorts that listed out all of the sponsors with a brief description. Kinda in the vein of what we have on the every-now-and-then  at TDWTF.   So, consider this the discussion for that topic.   What would you like to see in a sponsor gallery? Should it be one big, long list? How does the order get determined? Should we organize the sponsors based on tags (and if so, what about sponsors who target like java and .net)? What about former sponsors... do they get removed from the list, or go on like the "past sponsors" section/page?  Keep in mind that this is not something we intend to charge extra for... this is more a service to the you, the members, than anything else. I've gotten postive feedback from the TDWTF "gallery", as a lot of readers come through RSS, have adblock running, etc.


Virtualized Storage for other VMs on ESXi host

This question is two fold.  Part 1:  Is it a bad idea to virtualize a storage solution and run VMDKs off of that as opposed to the original VMFS datastore.  Essentially lets assume I have 2 TB worth of RAID'd DAS.  Currently I have a few VMDKs on the DAS VMSFS.  What I want to do is remove the VMDKs off the VMFS, allocate a good 1.8-1.9TB for a FreeNAS installation (a big FreeNAS VMDK), and run the other VMDKs off of that via NFS.  I don't have the hardware for a NAS but have a bunch of different shares.  This would simplify my management.  I understand there is some overhead with another layer of storage abstraction (A virtual ZFS file system over NFS backed by RAID'd DAS formatted as VMFS) but I don't see how it could be too bad.  The NAS also has more features than a simple VMFS datastore on DAS.  Part 2:  VMWare frowns on long running snapshots, but what about ZFS snapshots?  Is it safe\recomended to run my guest VMDKs (Windows clients, random servers) on ZFS snapshots?  This will give me the ability to quickly rollback VMs to earlier states without the implications of long running snapshots directly on the VMFS.


Do flight attendants prefer I press the button or walk to the back? (Long-haul flights)

I fly Abu Dhabi - Amsterdam - Portland, OR and back frequently.  Each leg is about 8 to 10 hours.  For most people, it is their one 'long flight,' and are sleeping, but for me, because I have two of them, it is a much longer day.  The shades are drawn and everyone's asleep, but I'd like to have a couple beers and watch a movie with my headphones.  Would cabin crew prefer I walk quietly to the back and ask them for a beer (this is what I usually do), or to press the call button.  I want to be as polite as possible.  I understand this might be subjective, but I'm hoping there's a universal rule-of-thumb.


How do I convert a date/time to epoch time (unix time/seconds since 1970) in Perl?

Given a date/time as an array of (year, month, day, hour, minute, second), how would you convert it to epoch time, i.e., the number of seconds since 1970-01-01 00:00:00 GMT?  Bonus question: If given the date/time as a string, how would you first parse it into the (y,m,d,h,m,s) array?


returning a function that uses a var declared in the parent function

this is a function that chooses items randomly from a given array until all are taken and only then repeating  i actually copied the code from a post because i couldn't understand how the variable copy's scope works .  PS : here's the post   thanks in advance for the help .  function randomNoRepeats(array) {   var copy = array.slice(0);   return function() {     if (copy.length < 1) { copy = array.slice(0); }     var index = Math.floor(Math.random() * copy.length);     var item = copy[index];     copy.splice(index, 1);     return item;   }; }  var chooser = randomNoRepeats(['Foo', 'Bar', 'Gah']); chooser(); // => "Bar" chooser(); // => "Foo" chooser(); // => "Gah" chooser(); // => "Foo" -- only repeats once all items are exhausted.


I tried to install opencv via homebrew, but I have done something wrong. I closed Terminal to restart it, however since then I can't open Terminal normally.    Last login: Wed Sep 20 23:23:15 on ttys001 -bash: /usr/local/bin/virtualenvwrapper.sh: No such file or directory -bash: touch: command not found Ys-MacBook-Air:~ hareentej22$ nano ~/.bash_profile -bash: nano: command not found Ys-MacBook-Air:~ hareentej22$ ls -bash: ls: command not found Ys-MacBook-Air:~ hareentej22$ cd .. Ys-MacBook-Air:Users hareentej22$ cd .. Ys-MacBook-Air:/ hareentej22$ ls -bash: ls: command not found Ys-MacBook-Air:/ hareentej22$ source ~/.bash_profile -bash: /usr/local/bin/virtualenvwrapper.sh: No such file or directory Ys-MacBook-Air:/ hareentej22$ nano ~/.bash_profile -bash: nano: command not found Ys-MacBook-Air:/ hareentej22$ xcode --version -bash: xcode: command not found Ys-MacBook-Air:/ hareentej22$ brew doctor -bash: brew: command not found Ys-MacBook-Air:/ hareentej22$ brew update -bash: brew: command not found Ys-MacBook-Air:/ hareentej22$    When I opened Terminal, I tried the above command lines, but none work. How can this be fixed?  edit : i run the command line as @allan mentioned and i get the following result .  Ys-MacBook-Air:~ hareentej22$ /bin/ls -la total 120 drwxr-xr-x+  32 hareentej22  staff   1088 Sep 17 03:12 . drwxr-xr-x    6 root         admin    204 Jul  9 10:43 .. -r--------    1 hareentej22  staff      7 Jul  8 20:16 .CFUserTextEncoding -rw-r--r--@   1 hareentej22  staff  16388 Sep 21 00:39 .DS_Store drwxr-xr-x    3 hareentej22  staff    102 Jul 17 00:55 .Seagate drwx------   72 hareentej22  staff   2448 Sep 20 23:24 .Trash -rw-------    1 hareentej22  staff  11027 Sep 20 01:01 .bash_history -rw-r--r--    1 hareentej22  staff    133 Sep 20 17:04 .bash_profile -rw-r--r--    1 hareentej22  staff      1 Sep 16 20:49 .bash_profile-miniconda3.bak drwx------  238 hareentej22  staff   8092 Sep 21 21:10 .bash_sessions drwxr-xr-x    4 hareentej22  staff    136 Sep 16 20:55 .conda drwxr-xr-x   10 hareentej22  staff    340 Aug 30 23:59 .eclipse drwxr-xr-x    3 hareentej22  staff    102 Aug 17 00:28 .netbeans-derby drwxr-xr-x    7 hareentej22  staff    238 Aug 17 00:30 .oracle_jre_usage drwxr-xr-x    8 hareentej22  staff    272 Sep  5 19:11 .p2 -rw-r--r--    1 hareentej22  staff    243 Sep 11 16:41 .profile drwxr-xr-x    5 hareentej22  staff    170 Sep 14 13:28 .pyenv -rw-------    1 hareentej22  staff     12 Sep 14 13:30 .python_history drwxr-xr-x    3 hareentej22  staff    102 Aug 30 23:48 .tooling -rw-------    1 hareentej22  staff   6232 Sep 17 00:23 .viminfo drwxr-xr-x   14 hareentej22  staff    476 Sep 17 03:13 .virtualenvs drwx------@   3 hareentej22  staff    102 Jul  9 11:02 Applications drwx------+  31 hareentej22  staff   1054 Sep 20 23:24 Desktop drwx------+   6 hareentej22  staff    204 Sep 12 22:30 Documents drwx------+  38 hareentej22  staff   1292 Sep 18 16:43 Downloads drwx------@  71 hareentej22  staff   2414 Sep 17 00:07 Library drwx------+   3 hareentej22  staff    102 Jul  8 20:16 Movies drwx------+   4 hareentej22  staff    136 Jul  8 20:36 Music drwxr-xr-x    2 hareentej22  staff     68 Jul 29 13:36 Parallels drwx------+   6 hareentej22  staff    204 Jul  9 10:00 Pictures drwxr-xr-x+   5 hareentej22  staff    170 Jul  8 20:16 Public drwxr-xr-x    3 hareentej22  staff    102 Aug 30 23:35 eclipse    Ys-MacBook-Air:~ hareentej22$ cat .bash_profile -bash: cat: command not found Ys-MacBook-Air:~ hareentej22$ Ys-MacBook-Air:~ hareentej22$ cat .bash_profile -bash: cat: command not found Ys-MacBook-Air:~ hareentej22$ /bin/cat .bash_profile export PATH=”/usr/local/opt/python/libexec/bin:$PATH”  # Virtualenv/VirtualenvWrapper source /usr/local/bin/virtualenvwrapper.sh


How can I Run/Download Android Apps on a PC?

I tried running Android 4.1.1 in VirtualBox, but it was too slow and sluggish to do anything. I came across Windroy which runs Android as a Windows app, but it won't run Google Play.  I want to run this on my laptop.  Any help would be greatly appreciated.


Im completely new to image editing, so excuse my immaturity... I have the following image:   I want to remove the writing on the blackboard and replace it with something different, keeping the original texture/smudges of the blackboard. What is the most efficient way for this in Gimp. I've tried for the last two hours and am becoming very angry because I can't get anything to work. Thanks for your help in advance.


Hypernym for "interpolation" and "extrapolation"

Interpolation typically means modeling the values of some curve inside the given data, and extrapolation — outside the given data. For example, if I know the temperature on Monday and Wednesday, and ask for what it was on Tuesday — this is interpolation. If I ask for what it was on Sunday before or Thursday after, it is extrapolation.  I am looking for a word that would encompass both. I thought of modeling, but is there perhaps something better?


I am familiar with BASIC calculus of single variable,multivariable,linear algebra,ordinary differential equations,.I HAVE NOT BEEN INTO RIGOROUS PROOFS .If someone can let me know book(s) which goes from basic to advanced level and contains lots of solved examples and exercises for self study .Also any online study material useful for this purpose will be great .I will be obliged .Thanks  NOTE :- I am not a Maths Major and has never been to college for studying Maths ,But studied from online sources available


Switching from battery to usb power source

I'm currently creating a small device to operate on a CR2032 battery when it is disconnected and a USB power when it is connected. I want the device to be powered by USB when it is connected, without any interruption in the power feed. So my question is: how to switch from battery to USB one the device is connected?  I thought to connect two diodes and a PNP transistor to turn the power based on the battery as soon as the USB is connected. But I wonder if this circuit consume many current when the USB is disconnected (consumption must be very low)?  The circuit :   If you have any solution which will consume less current please tell it to me !


Difference between left and right cosets

From my teacher's notes:  "Suppose $H$ is a subgroup of $G$. For any $a\in G$, we define its associated left coset and right coset to be $$aH = \{ab | b \in H\}$$ $$Ha = \{ba | b\in H\}$$ respectively."    What is a coset? What are the differences between left and right?  Also from the notes:  "Suppose $H$ is a subgroup of $G$. The left cosets $\{aH | a\in G\}$ define a partition of $G$, so are the right cosets." What does "define a partition of $G$" mean?


I have a class   @Component public class MessageServiceHelper {     @Autowired     private MessageService messageService;      public boolean sendMessage(String text){         return messageService.sendMessage(text);     }     public MessageService getMessageService() {         return messageService;     }      public void setMessageService(MessageService messageService) {         this.messageService = messageService;     } }   so here I am autowiring messageService, so that whenever the object ob MessageServiceHelper is instantiated then it will automatically inject dependency messageService into MessageServiceHelper. Same thing I can achieve if I have write some other class which will create the instance of MessageService and will call the setter method.   Now here the point can be raised is we have shifted the dependency resolution logic some where else and that code is coupled with the instantiation of MessageService and if some implementation is changed then I will have to change that class but with spring also If I have to change implementation I have to make change in metadata that I have given before.   so here my question is what is different with DI? What is strongest point about DI here?


How to permanently disable or remove preinstalled apps?

I have an older Google Nexus 4 (by LG), running 5.1.1 Lollipop (latest supported version). I want this to be my daughters first smartphone, and want to lock it down as much as possible.  So besides my own user account on the device I created a second user account for her. I installed the apps she should be able to use, but want to restrict others.  So I went on and disabled all apps she should not be able to use. However, all disabled apps keep re-appearing on her account after a day or so.  I went on and disabled automatic app updates on my own user and on her account, then went on and again disabled all apps on her account, but they keep re-appearing.  Question is: How can I permanently remove apps (especially the pre-installed apps like YouTube, Google, News, GMail, Hangouts, Play Books Play Music etc.) from her user account?  Rooting the device is not an option.


This question has been proposed to me and thus far it has baffled me:  $$ x + \sin(x) = k$$ solve for x.  Another way of looking at it is find $f^{-1}(x)$ given that $f(x)=x + \sin(x)$. Wolfram alpha doesn't even seem to know how to solve it, when you plug in a value for k, it tell you approximately the number but does not give an "exact" form. Any help?


Do we ever get more information about the Entwives?

During my recent re-reading of The Two Towers I was struck again by a question that has bothered me since I was a youngling: What on earth is up with the Entwives?  Treebeard says they went away in the distant past and just... got lost?  Did Tolkien ever make mention of them again, or is this one of those unsolved mysteries of Middle Earth?


You know when you type something into the address bar, and it comes up with suggestions and sites you have visited, is there any way to delete those?


Replace pattern each time with a different string (taken from external file)

I have an input:  a b TOCHANGE c d  e TOCHANGE   where I need to change the patterns "TOCHANGE" using an external file :  line1 line2 ...   so that I get the following output :  a b line1     c d e line2   I tried the following command :  while read k ; do sed -i "s/TOCHANGE/$k/g" input ; done < externalfile   but I got :  a b line1     c d e line1


Are badge progress numbers visible only to me or are they public?

Can other users see exact number of things (edit, votes, review jobs), that I should do, to reach next badge? Or are they only able to estimate this, by looking at my badges ("guy has , but not yet , so he edited between 80 and 500 posts" -- or something like that)?


How to solve a quintic congruence equation?

My textbook has this quadratic equation that I have to solve, any ideas how I could show that?  $$15 | (21n^5+10n^3+14n),\;\forall n\in\mathbb{Z}$$


Edit data in excel sheet through java ,getting null pointer exception

I am trying to update some entries in existing excel sheet .Below is my code   System.out.println("Update excel block");          FileInputStream fsIP= new FileInputStream("C:\\Users\\SXR8036\\Downloads\\LANE-804.xls");          // System.out.println(Path);          System.out.println("Trying to update the file");          HSSFWorkbook wb = new HSSFWorkbook(fsIP);//Access the workbook          HSSFSheet worksheet = wb.getSheetAt(0);//Access the worksheet, so that we can update / modify it           Cell cell = null;          cell = worksheet.getRow(2).getCell(2);// Access the second cell in second row to update the value           cell.setCellValue("OverRide Last Name");          fsIP.close(); //Close the InputStream           FileOutputStream output_file =new FileOutputStream(new File("C:\\Users\\SXR8036\\Downloads\\LANE-804.xls"));  //Open FileOutputStream to write updates           wb.write(output_file); //write changes           output_file.close();  //close the stream      I am getting NUll pinter exception as error >i have read quite about null pointer exception now but not able to find a solution to this.


Why does an electron shell further away from nucleus has higher energy level?

Using electrical potential energy $V=\frac{1}{4\pi \varepsilon_0} \frac{Q_1 Q_2}{r}$ , a particle further away from nucleus has lower magnitude of energy.  Using Coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit$^\star$ around that e-shell compared to a electron shell closer to nucleus, hence the one closer to nucleus supposedly should have higher energy.  $^\star$I know in reality $e^-$ does not orbit around a atom, but its position exists as a probability density or radial probability function.


What's the current SU password on version 15.04?

I want to change the SU password but it wont let me, what's the  current SU password on version 15.04?  It is a new install.


Can someone explain how to multiply two permutations? I cannot get myself to understand. Please be very simple and explain each step.


Will $Z[X] / (x^2 +1)$ be a PID?  My Try : It is not a PID. If $R$  = $Z[X] / (x^2 +1)$ were a PID then $2$ will be an irreducible element in $R$ and $R/(2)$ is a field. But $x$ will not have an inverse element in $R/(2)$. contradiction  Have I gone wrong anywhere? Please correct me if I have.  Thank You in Advance.


Unable to handle Too many SOQL queries Even after BULKIFY: 101

I have requirement like to display related records related to leads with sic code starts with.So i filtered with using Like operator but i am getting exception 101 exception.But i am not able to bulkify below code.  how to handle in this case.      public class LeadController      {         public String CurrentId;         public List<Opportunity> newopplist{get;set;}         public List<Opportunity> listopp{get;set;}          public LeadController(ApexPages.StandardController controller) {          CurrentId=ApexPages.currentPage().getParameters().get('id');         }          public void search()         {             set<String> cityset=new set<String>();             Map<String,String> citymap=new Map<String,String>();             Map<String,String> statemap=new Map<String,String>();             Map<String,String> Siccodes=new Map<String,String>();             List<Opportunity> newopplist=new List<Opportunity>();             for(Lead ld:[Select Id,City,State,SIC_Code_1__c from Lead where Id=:CurrentId ])             {                 // cityset.add(ld.City);                 if(ld.City <> null)                 {                     citymap.put(ld.City,ld.City);                 }                 if(ld.state <> null)                 {                     statemap.put(ld.State,ld.State);                 }                 if(ld.SIC_Code_1__c <> null)                 {                 Siccodes.put(ld.SIC_Code_1__c, ld.SIC_Code_1__c);                 }             }             newopplist=[Select Id,Name,Account.name,Number_of_Units__c,StageName,account.SIC_Code__c,Type,                         Billing_City__c,Billing_State_Province__c,account.SIC_Industry_Name__c,                         account.No_of_active_units__c from Opportunity where StageName='Closed Won' ];             listopp=new List<Opportunity>();             for(Opportunity opp: newopplist)             {                           if(!Siccodes.isEmpty())                 {                     Set<String> codes = new Set<String>();                     for(String code:Siccodes.keySet())                     {                         codes.add(code + '%');                     }                     listopp=[Select Id,Name,StageName,Account.name,Number_of_Units__c,account.SIC_Code__c,Type,                              Billing_City__c,Billing_State_Province__c,account.SIC_Industry_Name__c,                              account.No_of_active_units__c from Opportunity where account.SIC_Code__c                               LIKE :codes and StageName='Closed Won' ORDER BY account.No_of_active_units__c Desc Limit 10];                                      }        } }   I am hitting limits because of this query as per debug logs.     Select   Id,Name,StageName,Account.name,Number_of_Units__c,account.SIC_Code__c,Type,                                    Billing_City__c,Billing_State_Province__c,account.SIC_Industry_Name__c,                                    account.No_of_active_units__c from Opportunity where account.SIC_Code__c                                     LIKE :codes and StageName='Closed Won' ORDER BY account.No_of_active_units__c Desc Limit 10


“TeX Live Manager” not work (windows 10 - 64bit & texlive 2015)

I have just installed TeX Live 2015 using "install-tl-WINDOWS.bat"on windows 10-64bits.  When I click in "TeX Live Manager",nothing happens.  if I execute "tlmgr-gui" in a command line, nothing happens & no message appear.  if I execute "tlmgr -gui" or "tlmgr --gui" in a command line,I got this:  The locale codeset (cp720) isn't one that perl can decode, stopped at C:\texlive\2015\tlpkg\tlperl\lib/Encode/Locale.pm line 123. Compilation failed in require at C:\texlive\2015\tlpkg\tlperl\lib/LWP/UserAgent.pm line 1001..  what is the mistake?


Show that no set of nine consecutive integers can be partitioned into two sets with equal products

This problem is meant to be proved using contradiction and I've admittedly been stuck on it for some time. I'd really appreciate a point in the right direction, because it honestly feels like I've been getting nowhere.  This is all I've done:  Assume $x$ denotes the set of nine consecutive integers, and $x_1$ and $x_2$ denote the two partitions. We would have: $$\prod_{a\ \in \  x_1} a= \prod_{a\ \in \  x_2} a$$ $\implies$ $\prod_{a\ \in \  x_1} a$ and $ \prod_{a\ \in \  x_2} a$ are both even numbers, since both sets $x_1$ and $x_2$ would require to contain strictly odd numbers to have a product that is odd.  $\implies$ $x_1$ has at least two elements, one odd and one even.  $\implies$ $x_2$ has at most seven elements.  And that's where I hit a dead end. I thought perhaps I could represent the set $x$ as $$x := \{ (a_0, \ (a_0 +1), \ (a_0 +2), \ \dots , \ (a_0 +8) \}$$ where $a_0$ is any integer, then multiply things out and show in each case one side is less than the other, but then I noticed that'd be an extremely tedious route and that some of the more ugly expansions deserve some sort of proof by induction themselves to show whether or not they actually hold.  Please don't supply a proof that relies too heavily on a Number Theory-approach, as I don't have a background in that area therefore shouldn't rely on Theorems there to prove this.


How can I center the column values in this code?  \documentclass[conference]{IEEEtran} \begin{document} \begin{table}   \centering   \begin{tabular}{|p{2.5cm}|p{2.5cm}|p{2.5cm}|}     \hline     Reconstruction strategy & aa          & bb( \%) \\ \hline     Classic                 & 3342 voxels & 68 \%   \\ \hline     VC                      & 4296 voxels & 87 \%   \\ \hline     V m=7                   & 4745 voxels & 96 \%   \\ \hline   \end{tabular}   \newline\newline    \caption{title}\label{tab1} \end{table} \end{document}


Can industry experience make up for undergrad courses?

I am an undergraduate applied math and statistics major and plan on applying to PhD programs after graduation. My research interests are in machine learning, cv, etc.. And do research in the stats and CS department in ML/DL. I am thinking of applying to PhD CS programs, but have only taken 4 CS classes in undergrad, but I have had two internships with Amazon as a software engineer.  Can my experience in industry make up for the lack of CS classes as an undergrad?  I obviously want to get into the best program possible, but worried that my lack of CS classes might hinder my chances of getting accepted.  edit: Not a duplicate. Not worried about weak grades, gre, research, etc.. I am just wondering from a graduate admissions perspective will they look negatively on less CS classes even though I have research and industry experience in CS.


C++. Meaning of var1 = new (_field) Constructor()

I found this construction reading someone's else C++ code:  _worklist = new (_arena) Block_List();   I'm a little rusty on my C++, can someone explain what is going on here? I don't understand what this code is doing.  EDIT:  _arena is a field of type .   EDIT 2:  And here is the code of   Edit 3: My bad, I now understand  should have provide more context, here is the whole code:


Installing cuda-toolkit on ubuntu 15.10 hash sum mismatch

I am trying to install cuda-toolkit to my fresh ubuntu-15.10 . After reading the official instructions here http://developer.download.nvidia.com/compute/cuda/7.5/Prod/docs/sidebar/CUDA_Installation_Guide_Linux.pdf   lspci | grep -i nvidia 02:00.0 VGA compatible controller: NVIDIA Corporation G94 [GeForce 9600 GT] (rev a1)  uname -m && cat /etc/*release x86_64 DISTRIB_ID=Ubuntu DISTRIB_RELEASE=15.10 DISTRIB_CODENAME=wily DISTRIB_DESCRIPTION="Ubuntu 15.10"       gcc --version gcc (Ubuntu 5.2.1-22ubuntu2) 5.2.1 20151010   I downloaded the cuda-repo-ubuntu1504-7-5-local_7.5-18_amd64.deb file and run the following commands:  Installation Instructions:  sudo dpkg -i cuda-repo-ubuntu1504-7-5-local_7.5-18_amd64.deb  sudo apt-get update  sudo apt-get install cuda  But when I try installing cuda I get that message   E: Failed to fetch file:/var/cuda-repo-7-5-local/./cuda-visual-tools-7-5_7.5-18_amd64.deb  Hash Sum mismatch  E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?   I tried apt-get update and everything updated correctly. With --fix-missing? I get   Unable to correct missing packages. E: Failed to fetch file:/var/cuda-repo-7-5-local/./cuda-visual-tools-7-5_7.5-18_amd64.deb  Hash Sum mismatch  E: Aborting install.   Nvidia drivers under additional drivers section  Using NVIDIA binary driver-version 340.96 from nvidia-340(proprietary,tested)   If anyone has anything to suggest or if I did something wrong please help me I am new to Ubuntu as well to cuda . Thank you very much.


I'm working with a table that has about 50 colums and 100,000 rows.  One column, call it TypeID, has 10 possible values:  1 thourgh 10.  There can be 10,000 records of TypeID = 1, and 10,000 records of TypeID = 2 and so one.  I want to run a SELECT statement that will return 1 record of each distinct TypeID.  So something like  TypeID    JobID    Language    BillingDt    etc ------------------------------------------------ 1         123      EN          20130103     etc 2         541      FR          20120228     etc 3         133      FR          20110916     etc 4         532      SP          20130822     etc 5         980      EN          20120714     etc 6         189      EN          20131009     etc 7         980      SP          20131227     etc 8         855      EN          20111228     etc 9         035      JP          20130615     etc 10        103      EN          20100218     etc   I've tried:  SELECT DISTINCT TypeID, JobID, Language, BillingDt, etc   But that produces multiple TypeID rows of the same value. I get a whole bunch of '4', '10', and so on.  This is an ORACLE Database that I'm working with.  Any advise would be greatly appreciated; thanks!


Load java Script at the end of page. why?

I have listen a lot that we should always load the java script at the end of the page why we should do that. If i write the java script at starting of the page how it will make the difference?


how to `echo` 'formatted' man page of some command to text file

When I execute   echo `man ls` > tem.txt   I get unformatted output in the text file, I mean output without any new lines, just continues sentences. How do I get formatted output ? For example, unformatted output looks like:  LS(1) User Commands LS(1) NAME ls - list directory contents SYNOPSIS ls [OPTION]... [FILE]... DESCRIPTION List information about the FILEs (the current directory by default). Sort entries alphabetically if none of - cftuvSUX nor --sort is speci‐ fied. Mandatory arguments to long options are mandatory for short options too. -a.................


Why "hoist" in "Hoist with one's own petard"?

is one of my father's favorite phrases. As a child I had developed a vague understanding of the idiom in which petard was a kind of flag, which is why it was hoist, and being hoist by your own was an unpleasant fate bringing to mind captains being hung from their own ship's mast.   I now understand the meaning and origin of the phrase much better and know that a petard was a kind of early bomb and the idiom refers to being injured or killed by your own bomb. I am wondering about hoist though.   The Online Etymology Dictionary  that in this expression, hoist is a past participle. What confuses me is the usage. We would not use hoist to describe being thrown by a bomb today, it brings to mind a controlled movement and does not carry any connotations of speed or violence, quite the contrary:     hoist v. hoist·ed, hoist·ing, hoists v.tr.    1. To raise or haul up with or as if with the help of a mechanical apparatus. See Synonyms at lift.   2. To raise to one's mouth in order to drink: hoist a few beers. v.intr.   To become raised or lifted.   My question is whether hoist used to have such a connotation. Since the phrase can be traced to , was this poetic license or was the word commonly used to describe such violent movement at the time? Did to be hoist mean to die or be injured?


I know that live has several meanings, and two different pronunciations (/lɪv/ and /laɪv/), but I don't know which pronunciation I should use in each case. Can anybody clarify this?


"to prefer something over something" or "to prefer something to something"

Which syntax is more correct:     to prefer something over something else   or     to prefer something to something else   or maybe both are correct?


Proving the total number of subsets of S is equal to $2^n$

Student here! Just reading Liebecks Introduction to pure mathematics for fun and I made an attempt at proving the total number of subsets of S is equal to $2^n$.   I realized that the total number of subsets of S is just:  $ \binom{n}{1} + \binom{n}{2} + \cdots + \binom{n}{n} + 1$  And so I put together the cool looking formula  $ \displaystyle \sum_{r=1}^n \frac{n!}{r!(n-r)!} = 2^n - 1$  But I have no clue how to approach proving this formula analytically. Any help?    So if I try a proof by induction:  $\displaystyle \sum_{r=1}^n \frac{n!}{r!(n-r)!} = 2^n - 1$  $\displaystyle \sum_{r=0}^n \frac{n!}{r!(n-r)!} = 2^n$  obviously true for $n = 1$:  $1 + \frac{1}{1!0!} = 2 = 2$  assume true for $n$, I could multiply both sides by $2$?  $\displaystyle 2\sum_{r=0}^n \frac{n!}{r!(n-r)!} = 2^{n+1}$  How could I go about proving that  $\displaystyle 2\sum_{r=0}^n \frac{n!}{r!(n-r)!}  = \sum_{r=0}^{n+1} \frac{(n+1)!}{r!((n+1) - r)!}$


Given a dictionary like so:  my_map = {'a': 1, 'b': 2}   How can one invert this map to get:  inv_map = {1: 'a', 2: 'b'}


How to fix this "i need decimal places so for ".41" is gives 41 but for "9.41" it gives 40."

I'm solving cs50 pset1, I need first 2 decimal places. I'm trying to get it by converting the float I get from the user to int, then substracting it from float and then multiplying by 100 to get 2 decimal places  for ex input 9.41 after subustracting i get .410000 but when multiplying by 100 i get 40.9999 as output whereAS I need exact 41 so i can convert to int      #include<stdio.h>     #include<cs50.h>     #include<math.h>      int main(void)     {         int i = 0;         float number = get_float("Enter change: ");         printf("%f \n",number);         int integer = (int)number;         printf("%i \n",integer);         float change = number - integer;         printf("%f \n",change);         change = change * 100;         printf("%f \n",change);         int n = (int)change;          printf("%i \n",n);     }   expected:   Enter change: 9.41 9.410000  9  0.410000  41.000000  41    actual:  Enter change: 9.41 9.410000  9  0.410000  40.999985  40


Forward declaring a class and a namespace in a .h for use in a .cpp

I'm trying to forward declare the mat4 class from the glm library. I want to create a camera class to handle all of my camera matrix information, but am having trouble writing the head without having to include the glm files in my header.  my header is as follows:  #pragma once  namespace glm {     class mat4; }  class Camera { public:     Camera();     ~Camera();  private:     glm::mat4 projection;     glm::mat4 view;     glm::mat4 model;     glm::mat4 MVP; };   for every member, I get error C2079: 'Camera::[member]' uses undefined class 'glm::mat4'  I really need help. Thank you in advance.


PCA and proportion of variance explained

In general, what is meant by saying that the fraction $x$ of the variance in an analysis like PCA is explained by the first principal component? Can someone explain this intuitively but also give a precise mathematical definition of what "variance explained" means in terms of principal component analysis (PCA)?  For simple linear regression, the r-squared of best fit line is always described as the proportion of the variance explained, but I am not sure what to make of that either. Is proportion of variance here just the extend of deviation of points from the best fit line?


I have an executable file mpiexec, whose full path is ~/petsc-3.2-p6/petsc-arch/bin/mpiexec.  Since I want to execute this command in different directories (without having to retype the entire path), I setup an alias in my home .bashrc file:    alias petsc="~/petsc-3.2-p6/petsc-arch/bin/mpiexec"     which allows me to execute this mpiexec file at the command prompt easily by typing:    petsc myexecutable   I tried to write a shell script file, named script, using my new alias petsc as a command.  After giving my shell script the appropriate permissions (using chmod), I tried to run the script.  However, it gave me the following error:    ./script: line 1: petsc: command not found   I know that I could just write the full path to the mpiexec file, but it is cumbersome to write the full path everytime that I want to write a new script.  Is there a way that I can use my alias petsc inside the script file?  Is there a way I can edit my .bashrc or .bash_profile to make this happen?


What's an expression for a cunningly-fake friend?

I'd like to warn somebody of one of their harmful managers, or even a so-called fake friend, so I say it like this:     Don't trust him! He is nothing but a cunning person who is trying to harm you/put you down, with his special ability , so gradually, *smoothly,softly, wisely, and, secretly* via a pre-planned plot that you won't even notice or suspect his intentions.   What idiom, phrase, term, ... could be used for describing this wise person/ fake friend/whatever you name it, -or his ability-*while focusing on using his wisdom for doing his hidden harmful actions smoothly!  P.S 1: I have found "back-stabber"; "two-faced"; "a snake in the grass"; "a wolf in sheep's clothing"; but none of them cover all those attributes as a whole.     -(there is an idiom in my country which says" Don't trust him! He cuts off the throats/ heads with cotton!)   -( these people are potentially good politicians!, so you can use this idiom even for countries or politicians who achieve their goals by acting in this way!)   Note: my question has been marked as "duplicate", but the answer I'm looking for, has nothing to do with answer which user87131 is looking for, he/she is focusing on a liar fake friend, and me, on some other attributes and actually maybe this person is not necessarily a friend, maybe he is someone whom I am obliged to deal with,!!. Please reopen my question, if possible! -(Sorry, Everybody! I had to edit my question!)     P.S2: I just found these political terms: "Soft War", "soft power"! And both can totally convey the meaning I am looking for, so Can I use them In non-political cases, too? , Like: , "Don't trust him, he is good at soft war!/ he is good at applying soft power"?


How many sequences of $n$ tosses of a coin that do not contain two consecutive heads have tails as the first toss?

If you toss a coin $n$ times, there are $2^n$ possible sequences of heads and tails. Let $E_n$ be the set of sequences which do NOT contain two consecutive heads and $e_n$, the number of sequences in $E_n$.  Thus $E_3$ $=$ $\{$ $TTT$, $TTH$, $THT$, $HTT$, $HTH$ $\}$ and $e_3$ $=$ $3$.  How many elements of $E_n$ have $T$ as the first toss?  Please can anyone help me out here?


Probability question of independent random varaibles

Let  $X\sim \mathcal{N}(6,1)$ and $Y\sim\mathcal{N}(7,1)$ be two independent normal variables. Find $Pr(X>Y)$. the answer is $0.2389$ but I do not know how to do it.


What is an intuitive way of understanding Ostrogradsky instability?

Is there a way of explaining why no differential equations in physics exceed order two without delving into Lagrangian and Hamiltonian mechanics - i.e. from Newtonian mechanics? Moreover, is there such an alternative proof, which focuses more on physical reasoning than abstract mathematics?


No wifi options Ubuntu 16.04 LTS - running on an old MacBook Air

I installed Ubuntu 16.04 LTS on an old MacBook Air that had ceased working (pinwheel of death, OS X wouldn't boot). Wiped OS X from the machine on install. The idea was to get some additional usage out of a machine that otherwise would be headed for the trash. Ubuntu works just fine, and connected to the wifi during install.   On restarting, however, it now says "No network devices are available", and can't see wifi network(s).  Please note that its a Mac and only has USB and Thunderbolt ports–so cannot connect to ethernet.   I'm not very techie, and new to Ubuntu, so any suggestions please be plain and practical. Thanks!  UPDATE:  02:00.0 Network Controller [0280]: Broadcom Corporation BCM43224 802.11a/b/g/n [14e4:4353] (rev 01) Subsystem: Apple Inc. Airport Extreme [106b:00e9] Kernel modules: bcma 03:00.0 PCI Bridge [0604]: Intel Corporation DSL3510 Thunderbolt Port [Cactus Ridge] [8086:1547] (rev 03)  SUGGESTED SOLUTION:     The needed driver bcmwl-kernel-source, is on the installation media.   Please check here: askubuntu.com/questions/835475/…   DIDN'T WORK:  FATAL: Module wl not found in directory lib/modules/4.13.0-26-generic" . Wifi still not working.   FOLLOW-UP     What version is the deb file?   bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu3_amd64.deb? Note it   should be xx-0ubuntu3. If not, I will un-dupe the question and propose   an answer. – chili555 1 hour ago   RESPONSE:     It appears to be 0ubuntu1~1.1   FURTHER UPDATE:  Did as suggested here:     I suggest that you download this package on some other computer and   put it on a USB key or similar.      Transfer it to the Ubuntu computer to some convenient place such as   the desktop. Now, in the terminal:   The "arch" command result was was fine with following result:  x86_64   I then followed the further commends in terminal and got following result:  dpkg: error: dpkg status database is locked by another process   FIXED!  Thanks guys, the last fix suggested worked fine, and my Ubuntubook is now connected to the internet. Good job.


How do I scale a letter how it should be?

I would like to extrude & scale the outter edge of my letter like this :  but Actually it looks like this ...  I have no clue how to do it ... Also  there is another problem,  if I scale a mesh is there a way to deactivate the z axis ?


when and how to use overloaded operator( )

In lots of C++ book I have seen they  use overload  operator '( )' .      I still don't understand when and how to use it.  For example I know how to implement or overload '+' operator for a class or '='. I also exactly know when to use these operators but just cant understand about operator '()'.  Can some please guide me may be by an example. I have googled and I found about tutorials related to overloading .


show that $x-x^{3}/6 0$. ( taylor series)

the question in a random study problem says show that x - $\frac{x^3}{6} < sinx< x $ for $x>0$. ( taylor series). I am assuming the question means about x=0 I have tried finding the maximum error which you end up as lagrange $R (2) < \frac{x^3}{6}$ but that only lets me prove $sinx<x$


Which preposition should be used in "married _______ the week after Easter": on, at or in?

I came across this sentence, where a student has to insert a correct preposition.  For each sentence, fill in the blank with either on, at, or in. They got married _______ the week after Easter.  The answers say in is correct, but I feel a little confused. Is the book right?


What do you feel when crossing the event horizon?

I have heard the claim over and over that you won't feel anything when crossing the event horizon as the curvature is not very large. But the fundamental fact remains that information cannot pass through the event horizon so you cannot feel your feet when they have passed it.  Is there a way to cross the even horizon at reasonable speed in radial direction (below say 0.01*c )? So what would it really be like?


Problem: Let $R$ be a ring such that $\Bbb Z \subset R \subset \Bbb Q$. Show that $R$ is a PID. Hint: If $I$ is an ideal of $R$ consider $A=\Bbb Z \cap I$.  Following the hint, if $I$ is an ideal of $R$, then $A$ is the set of rationals in $I$ where the denominator is $1$, and moreover since $\Bbb Z$ is an ideal of $R$, then $A$ is an ideal of $\Bbb Z$, and so is principle. This is about as far as I've gotten, insights appreciated.


What are droids in Star Wars powered by?

A friend posed this question a while back and despite searching the internet and our collective Star Wars books, we were unable to come up with an answer. I even made , but with no real luck. I understand that droids are machines and that they need to "rest" every 100 hours or so to recharge themselves, but what are they recharging? Do they use some kind of batteries? Do they create their own energy somehow? In Episode IV, we see Threepio "switch off", presumably to store power, and in Episode V, Luke plugs Artoo into some sort of power inverter to power his camp. Does anyone have any documentation on what exactly keeps a droid running?


Should I charge extra for project files?

I've recently been offered a job designing a flyer for an event that a local organization is hosting. I was asked if I could also include the project files so they could easily alter the design for the next year of this event (it's a yearly competition).  This is no problem with me and I will be sending them the project files for the design. What I do wonder however is if it is good practice to charge a bit extra for doing this? And if so, how much (in relation to the original cost) extra should I charge?  Thanks for your input!


Visual C# : I cannot access a label for changing the text inside a task

Take a look at the following script:   await Task.Run(() =>  {                      //Importing data from OMDB                     WebClient OMDB = new WebClient();                     string ReqURL = "http://www.omdbapi.com/?t=the+revenant&apikey=***";                     var RawData = OMDB.DownloadString(ReqURL);                     var JsonData = JsonConvert.DeserializeObject<csOMDBData.Rootobject>(RawData);                     var OMDBData = JsonData;                     txtReport.text = "Done!"; });   I'm using this script for converting a raw data that I get by an API form OMDB to JSON. After converting, I need to change the text of a label called "txtReport" to "Done!" but I get the "Cross-thread operation in not valid!" error!   I have red all the related posts but couldn't find such a situation (Inside a task)! & because I'm new to Visual C# I don't even understand the solutions. If you can, please edit my script, I will learn by edited script. Thanks a lot...


What is the remainder of dividing $14^{256}$ by $17$?


Is it possible to prove $0 \neq 1$ in (non-univalent) Martin-Löf type theory, where $0$ and $1$ are natural numbers (defined using the usual inductive type $0 : \mathbb{N}$, $S : \mathbb{N} \to \mathbb{N}$)?


Probability that a stick randomly broken in two places can form a triangle

Randomly break a stick (or a piece of dry spaghetti, etc.) in two places, forming three pieces.  The probability that these three pieces can form a triangle is $\frac14$ (coordinatize the stick form $0$ to $1$, call the breaking points $x$ and $y$, consider the unit square of the coordinate plane, shade the areas that satisfy the triangle inequality edit: see comments on the question, below, for a better explanation of this).  The other day in class*, my professor was demonstrating how to do a Monte Carlo simulation of this problem on a calculator and wrote a program that, for each trial did the following:   Pick a random number $x$ between $0$ and $1$.  This is the first side length. Pick a random number $y$ between $0$ and $1 - x$ (the remaning part of the stick).  This is the second side length. The third side length is $1 - x - y$. Test if the three side lengths satisfy the triangle inequality (in all three permutations).   He ran around $1000$ trials and was getting $0.19$, which he said was probably just random-chance error off $0.25$, but every time the program was run, no matter who's calculator we used, the result was around $0.19$.  What's wrong with the simulation method?  What is the theoretical answer to the problem actually being simulated?  (* the other day was more than $10$ years ago)


Data collector mobile app with mapping capabilities

At work we have a GIS solution platform with 50+ GB of data in a Postgres cluster. Almost all tables have spatial columns. We have several clients consuming this information for different needs.   I'm looking for the best mobile solution for field data collection and visualization.  There is an old question about this, but since it is 4 years old, probably a lot of things had changed.   To summarize, the main requirements are: - Mobile app (Android mandatory, iOS non-mandatory) - Base maps (OSM, Google, Bing, etc) - View OGC mapping data (WMS, WFS, etc) - View forms with specific information of every layer  - Capable of adding new geometries (point, polygon, polyline) to a layer, and adding specific alphanumeric data using an associated dynamic form. This data can hit an WFS-T service - Work offline. That includes basemaps (like a local tile cache), and vector data - If some data was collected offline, it need to sync that data with the service/database  And in top of that, some clients have very specific requirements for their mobile apps. For instance, to some of them, the normal data collection app is enough, but maybe another client have a procedure in the field that requires special features. So, the possibility of development is really welcome, may be via an SDK or something similar.   What are the actual alternatives to accomplish this?


How to treat rare / new items in the validation of a recommender system?

I'm working on movie recommendation algorithm. The data set consists of about 40 million ratings (user, film, rating). I want to separate the ratings into two groups - training set and probe set. The training set will be used for training, probe set for checking that the algorithm doesn't overfit the data.  My first plan was to try to follow this approach: . They create the probe set by taking the last 3 ratings from every user (and every user is guaranteed to have 20+ ratings). But the problem is, what if there is some really new film whose all ratings are in the probe set? The training algorithm wouldn't have any info about this film.


Is there a sane reason why ¹⁄₁₂₅ is not, instead, exactly half of ¹⁄₆₀?

Here are some common shutter speeds you will find on most DSLR cameras:   1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000   As you move from left to right, or as you increase the shutter speed, you are halving the amount of light that hits the sensor. In other words, you are decreasing the amount of light by one stop for each step. So 1/30 is half of 1/15, and 1/60 is half of 1/30. But then you come to 1/125, which is not half of 1/60. Half of 1/60 is 1/120. This is basic math.  So you break the sequence or pattern. But as you continue, it starts to make sense again. So 1/250 is in fact half of 1/125, and 1/500 is in fact half of 1/250, and 1/1000 is in fact half of 1/500, so on and so forth.  So there appear to be two distinct sequences here.   1/15, 1/30, 1/60 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000   Is there a sane reason for this?  I know that people sometimes talk about half stops or even thirds of a full stop. But then what is 1/125 the half stop, or third stop of? If you increase 1/60 by a third you get 1/180. This setting does not exist in the standard sequence. The closest you will get is 1/160. If you increase 1/60 by a half, you get 1/120 and it doesn't exist either.  Is this all arbitrarily set by the camera manufacturers, or is there perhaps some reason and history behind this?


Highlighting rows/columns/diagonals in matrix

I'm trying to highlight rows/columns/diagonals in a matrix. I came across , which looks very clean. Unfortunately, it seems to cause some issue with spacing in the matrix, and I can't figure out why. Below is a MWE and the output:  \documentclass{article} \usepackage{amsmath} \usepackage{tikz}  \newcommand{\tikzmark}[2]{     \tikz[overlay,remember picture,baseline]      \node[anchor=base] (#1) {$#2$}; }  \begin{document}  No highlighting: \begin{equation}   A =   \begin{bmatrix}     a_{11} & 0 & 0 \\     0 & a_{22} & 0 \\     0 & 0 & a_{33}\\   \end{bmatrix} \end{equation}  Highlighting: \begin{equation}   A =   \begin{bmatrix}     \tikzmark{top}{a_{11}} & 0 & 0 \\     0 & a_{22} & 0 \\     0 & 0 & \tikzmark{bottom}{a_{33}}\\   \end{bmatrix} \end{equation} \begin{tikzpicture}[overlay,remember picture]   \draw[opacity=.4,line width=3mm,line cap=round] (top.center) -- (bottom.center); \end{tikzpicture}  \end{document}     What is the \tikzmark command doing, and is there anything that can be done to preserve the standard matrix spacing?


Why does the C++ compiler create an object heap instead of pushing the class object in stack?

On creating a class object with 'new' keyword,why is an object heap created instead of stack?Would stack not be a better option since it is faster,performs contiguous allocation and does not need manual deletion(free/delete)? If objects of a particular class have the same template then why do we need dynamic allocation?(justification for heap) [×××Please note that my doubt is not about which option a programmer must choose,but instead about why the compiler behaves the way it does in the above case.×××]


let $V$ be a real vector space. I would like to know what is meant by a "polynomial map" $f:\times^k V\rightarrow \mathbb{R}.$  I suppose the space $\times^k V$ is the cartesian product $V^k$ and therefore a vector space by itself. In algebra textbooks I could found the definition of polynomials $R[X]$ or even $R[X_1,...,X_n]$ for any ring $R$. But in the above situation, $\mathbb{R}$ is the only ring I can recognize.   My background is more in the realm of analysis than in algebra. So I would be very happy if anyone can tell me with my issue in simple language...  Best wishes


Should I wait with posting an answer to my own question?

What is preferred and more valuable for the SO community when I find an answer to my own question?  Should I wait with my answer (even when I know it is 100% correct and to the point) to give others a chance to earn some reputation points, or should I just post an answer straight away?  My main concerns are:   Not to give users a feeling that the question has been asked for 'autopromotion' purposes when author already knows the answer upfront. Find a balance between motiving / inviting others to collaborate with valuable answers and sharing the knowledge immediately.


What is the difference between "why are you worried" and "why you are worried"?

What is the difference between these two sentences?     Why are you worried?   Why you are worried?   Which one is correct?


If $f:[0,1]\rightarrow [0,1]$ is increasing function. Suppose $0<f(0),f(1)<1$. Show $f$ has fixed point.

A Fixed point of $f$ is a point $r$ such that $f(r)=r$.   I am not really convinced by this theorem holds for any function (even discontinuous functions). For example, I sketched this function:    This function has $f(0)>0, f(1)<1$, it is increasing and has no value $r$ where $f(r)=r$. Am I missing something or did the question miss a condition?


For loop in Unix : including files from sub directories

A simple for loop in Unix would be:  for FILE in $BASE_WORK_DIR/*.pdf    do      echo $FILE    done   This will echo all .pdf files inside BASE_WORK_DIR directory.   What if BASE_WORK_DIR contains sub directories as well which also contain the pdf file.  In that case how can I design my for loop to take all pdf files from BASE_WORK_DIR as well as sub directories of BASE_WORK_DIR ?


Can I copy PS4 game save data from old user to a new user?

I'm trying to transfer my Final Fantasy XV game save data to my new user?


Differences between the major abstract algebra books

I currently have Dummit and Foote, but I was thinking of getting another textbook on abstract algebra to complement it. I've come across a few popular titles, but I'm not sure if they're different enough from D&F. What are your thoughts on the differences and approachability of the major abstract algebra books? Some of the popular titles that I've seen are:  Abstract Algebra by Dummit and Foote A First Course in Abstract Algebra by Fraleigh Algebra by Artin Contemporary Abstract Algebra by Gallian and any other book you recommend


Where is the logical error resulting in my negative variance?

I have three random variables $X,Y,Z$ that all have a mean of $\mu=10$ and a standard deviation of $\sigma=2$. Now, I would like to say that they are negatively correlated with $\rho_{X,Y}=-1, \rho_{Y,Z}=-1, \rho_{X,Z}=-1$.  My question would be, what is the variance of $X+Y+Z$? Normally, we would say: $Var(X+Y+Z)=Var(X)+Var(X)+Var(Z)+2Cov(X,Y)+2Cov(Y,Z)+2Cov(X,Z)$  However, in our simple example, this leads to $3\cdot2^2+3\cdot2\cdot(-1)\sqrt{2^2\cdot2^2}=-12$ which cannot make sense.  Where is my logical error? I presume because of some transitivity, $\rho_{X,Z}$ cannot be $-1$ if the other two $\rho_i$ are -1 but which principle is behind this?


If there is a point on a chord of a circle, which point on the minor arc would make the length between the the two points the smallest?

If segment mn is a diameter of a circle f, and v is a fixed point on mn, for which point E on MN is the length FE minimized?


Was there originally a non-ribosomal way of synthesizing proteins?

Proteins are synthesized on ribosomes from mRNA copies of regions of the DNA. But ribosomes themselves are made up of proteins (and RNA). So how could the first ribosomes have arisen? Was there previously some other way of making proteins other than by ribosomes and mRNA?


Hey guys I've been trying for the last 3 hours to work out how to get WinUSB to get this onto my USB but it keeps giving me failed when I try I thought it was permissions so I tried   chmod 777   but it still wouldn't have it here are the errors any help is appreciated  Installation failed ! Exit code: 512 Log: Formating device... Mounting... mount: block device /james/Windows_8.1_Pro_X64_Activated_Final/Windows_8.1_Pro_X64_Activated.iso is write-protected, mounting read-only Copying... Error occured ! Syncing... Cleaning... /usr/bin/winusb: line 78: 14111 Terminated              while true; do     sleep 0.05; echo 'pulse'; done Umounting and removing '/media/winusb_iso_1389165798_11743'... umount: /media/winusb_iso_1389165798_11743: device is busy.         (In some cases useful info about processes that use          the device is found by lsof(8) or fuser(1)) Umounting and removing '/media/winusb_target_1389165798_11743'...


In my application i have been using retrofit for my webservice calls. It is not working fine. This is the error that caused when my application started     04-16 07:41:26.162 5860-5860/com.pance.taugaksih E/AndroidRuntime: FATAL EXCEPTION: main                                                                      java.lang.NullPointerException                                                                          at com.pance.taugaksih.activity.SplashscreenActivity$1.success(SplashscreenActivity.java:54)                                                                          at com.pance.taugaksih.activity.SplashscreenActivity$1.success(SplashscreenActivity.java:42)                                                                          at retrofit.CallbackRunnable$1.run(CallbackRunnable.java:45)                                                                          at android.os.Handler.handleCallback(Handler.java:725)                                                                          at android.os.Handler.dispatchMessage(Handler.java:92)                                                                          at android.os.Looper.loop(Looper.java:137)                                                                          at android.app.ActivityThread.main(ActivityThread.java:5041)                                                                          at java.lang.reflect.Method.invokeNative(Native Method)                                                                          at java.lang.reflect.Method.invoke(Method.java:511)                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)                                                                          at dalvik.system.NativeStart.main(Native Method)   This is my code that callled retrofit with response NullpointerExeption   RESTClient.get().getPost(new Callback<ResponsePost>() {         @Override         public void failure(RetrofitError error) {             // TODO Auto-generated method stub             progress.dismiss();             Toast.makeText(getApplicationContext(), "AKSES KE SERVER GAGAL" + error.getMessage(), Toast.LENGTH_LONG).show();             finish();         }          @Override         public void success(ResponsePost post, Response response) {             // TODO Auto-generated method stub             if (post.getPost().size() > 0) {                 PostController chb = new PostController(myContext);                 chb.open();                 chb.deleteData();                 for (int y = 0; y < post.getPost().size(); y++) {                     PostModel tmpHasil = post.getPost().get(y);                     chb.insertPost(tmpHasil);                 }                 chb.close();                  Intent sendIntent = new Intent(myContext,PostActivity.class);                 startActivity(sendIntent);                 finish();             } else {                 Toast.makeText(getApplicationContext(), "DATA SEDANG TIDAK TERSEDIA", Toast.LENGTH_LONG).show();             }             progress.dismiss();         }     });   And this is code my RESTClient class  public class RESTClient { private static APIPost REST_CLIENT; private static String URL_TAUGAKSIH = "http://10.108.109.30/taugaksih_slim";  static {      setupRestClient(); }  private RESTClient() {}  public static APIPost get() {     if(REST_CLIENT==null){         setupRestClient();     }       return REST_CLIENT; }  private static void setupRestClient() {     RestAdapter builder = new RestAdapter.Builder().setEndpoint(URL_TAUGAKSIH).build();     REST_CLIENT = builder.create(APIPost.class); }   }


Prove that every totally ordered set has a well-ordered cofinal subset

I thought this was easy until I realized that for a set to be well-ordered, EACH of it's non-empty subsets must have a least element.  Let $A$ be a non-empty totally ordered set. Let $x_0$ be some element of $A$. Define $S=\{x\in A|x\ge x_0\}$. $x_0 \in S$ so $S$ isn't empty.  Now, this seems like it would work. It certainly is totally ordered and cofinal in $A$, but it might not be well-ordered.  For example, if $A=\mathbb R$ then $(x_0 + 1, x_0 + 2)$ (where $()$ denotes an open interval) is a non-empty subset of $S$, but doesn't have a least element.