Here are a few ways:

  - `Sys.getenv(&quot;R_ARCH&quot;)` returns either `&quot;/i386&quot;` or `&quot;/x64&quot;` at least on my Windows system (but not on my Ubuntu system where it returns an empty string)

  - `Sys.info()[[&quot;machine&quot;]]` returns `&quot;x86_32&quot;` or `&quot;x86_64&quot;` on my Windows and Ubuntu systems.

**Updated:** With additional method.

Rather than needing to remember the designations of various OS&#39;s, the canonical cross-platform method is to look at:

    &gt; .Machine$sizeof.pointer
    [1] 8   # 8 bytes for address is 64 bits.

This is the address space for R objects. (It&#39;s not the address space for the OS.) 

Your platform says `x86_64-w64` in front of the `mingw32`. Your arch is similarly `x86_64`. That means you&#39;re running 64-bit, on 64-bit Windows.

For reference, the corresponding arch for 32-bit R would be `i386`.

You may have multiple versions of R installed. To change versions in RStudio: Tools -&gt; Global Options -&gt; R Version...Change...

I choose &quot;Use the machine&#39;s default version of R64 (64-bit),&quot; since my OS is Windows 8 x64.


I like intellij&#39;s code/file templates, they are working really well for me for single files but it would be great to be able to create multiple files/classes at once.

I did find [this question](https://stackoverflow.com/questions/8142937/does-intellij-support-any-kind-of-templating-to-create-multiple-files-automatica) but since it has been a few years since I was hoping that things might have changed.

We are using the mvp pattern in our application so every time we want to create a new view, it requires two classes and two interfaces, which are always in the same pattern. It would be awesome if we could generate all of the infrastructure for this and link up the classes.

Any suggestions or new information would be appreciated?
Maybe it is time to log a feature request with [JetBrains](http://www.jetbrains.com)?

Is there a way to generate multiple files/classes with intellij code/file templates?

I&#39;m using the following to try and insert a record into a postgresql database table, but it&#39;s not working. I don&#39;t get any errors, but there are no records in the table. Do I need a commit or something? I&#39;m using the postgresql database that was installed with the Bitnami djangostack install.

    import psycopg2
    
    try:
        conn = psycopg2.connect(&quot;dbname=&#39;djangostack&#39; user=&#39;bitnami&#39; host=&#39;localhost&#39; password=&#39;password&#39;&quot;)
    except:
        print &quot;Cannot connect to db&quot;
    
    cur = conn.cursor()
    
    try:
        cur.execute(&quot;&quot;&quot;insert into cnet values (&#39;r&#39;, &#39;s&#39;, &#39;e&#39;, &#39;c&#39;, &#39;w&#39;, &#39;s&#39;, &#39;i&#39;, &#39;d&#39;, &#39;t&#39;)&quot;&quot;&quot;)
    except:
        print &quot;Cannot insert&quot;



Python psycopg2 not inserting into postgresql table

My version output is:

    &gt; version
                   _                            
    platform       x86_64-w64-mingw32           
    arch           x86_64                       
    os             mingw32                      
    system         x86_64, mingw32              
    status                                      
    major          2                            
    minor          15.2                         
    year           2012                         
    month          10                           
    day            26                           
    svn rev        61015                        
    language       R                            
    version.string R version 2.15.2 (2012-10-26)
    nickname       Trick or Treat    

where os is mingw32. Does that mean I&#39;m using only 32 bits? How can I change that?



How can I know if R is running on 64 bits versus 32?

My version output is:
<pre><code class="hljs language-sql">> version
 _ 
platform x86_64-w64-mingw32 
arch x86_64 
os mingw32 
system x86_64, mingw32 
status 
major 2 
minor 15.2 
year 2012 
month 10 
day 26 
svn rev 61015 
language R 
version.string R version 2.15.2 (2012-10-26)
nickname Trick or Treat 
</code></pre>
where os is mingw32. Does that mean I'm using only 32 bits? How can I change that?

For example if I have this:

   

    n = c(2, 3, 5) 
    s = c(&quot;aa&quot;, &quot;bb&quot;, &quot;cc&quot;) 
    b = c(TRUE, FALSE, TRUE) 
    df = data.frame(n, s, b)

      n  s     b
    1 2 aa  TRUE
    2 3 bb FALSE
    3 5 cc  TRUE

Then how do I combine the two columns `n` and `s` into a new column named `x` such that it looks like this:

      n  s     b     x
    1 2 aa  TRUE  2 aa
    2 3 bb FALSE  3 bb
    3 5 cc  TRUE  5 cc



Combine two or more columns in a dataframe into a new column with a new name

I tried to replace `NaN` values with zeros using the following script: 

    rapply( data123, f=function(x) ifelse(is.nan(x),0,x), how=&quot;replace&quot; )
    # [31]   0.00000000  -0.67994832   0.50287454   0.63979527   1.48410571  -2.90402836

The NaN value was showing to be zero but when I typed in the name of the data frame and tried to review it, the value was still remaining NaN.

    data123$contri_us
    # [31]          NaN  -0.67994832   0.50287454   0.63979527   1.48410571  -2.90402836

I am not sure whether the `rapply` command was actually applying the adjustment in the data frame, or just replaced the value as per shown.

Any idea how to actually change the `NaN` value to zero?

How to replace NaN value with zero in a huge data frame?

I have a script that reads in data from a CSV file into a `data.table` and then splits the text in one column into several new columns. I am currently using the `lapply` and `strsplit` functions to do this. Here&#39;s an example:

    library(&quot;data.table&quot;)
    df = data.table(PREFIX = c(&quot;A_B&quot;,&quot;A_C&quot;,&quot;A_D&quot;,&quot;B_A&quot;,&quot;B_C&quot;,&quot;B_D&quot;),
                    VALUE  = 1:6)
    dt = as.data.table(df)

    # split PREFIX into new columns
    dt$PX = as.character(lapply(strsplit(as.character(dt$PREFIX), split=&quot;_&quot;), &quot;[&quot;, 1))
    dt$PY = as.character(lapply(strsplit(as.character(dt$PREFIX), split=&quot;_&quot;), &quot;[&quot;, 2))

    dt 
    #    PREFIX VALUE PX PY
    # 1:    A_B     1  A  B
    # 2:    A_C     2  A  C
    # 3:    A_D     3  A  D
    # 4:    B_A     4  B  A
    # 5:    B_C     5  B  C
    # 6:    B_D     6  B  D 

In the example above the column `PREFIX` is split into two new columns `PX` and `PY` on the &quot;_&quot; character.

Even though this works just fine, I was wondering if there is a better (more efficient) way to do this using `data.table`. My real datasets have  &gt;=10M+ rows, so time/memory efficiency becomes really important.

---

### UPDATE:

Following @Frank&#39;s suggestion I created a larger test case and used the suggested commands, but the `stringr::str_split_fixed` takes a lot longer than the original method.

    library(&quot;data.table&quot;)
    library(&quot;stringr&quot;)
    system.time ({
        df = data.table(PREFIX = rep(c(&quot;A_B&quot;,&quot;A_C&quot;,&quot;A_D&quot;,&quot;B_A&quot;,&quot;B_C&quot;,&quot;B_D&quot;), 1000000),
                        VALUE  = rep(1:6, 1000000))
        dt = data.table(df)
    })
    #   user  system elapsed 
    #  0.682   0.075   0.758 

    system.time({ dt[, c(&quot;PX&quot;,&quot;PY&quot;) := data.table(str_split_fixed(PREFIX,&quot;_&quot;,2))] })
    #    user  system elapsed 
    # 738.283   3.103 741.674 

    rm(dt)
    system.time ( {
        df = data.table(PREFIX = rep(c(&quot;A_B&quot;,&quot;A_C&quot;,&quot;A_D&quot;,&quot;B_A&quot;,&quot;B_C&quot;,&quot;B_D&quot;), 1000000),
                         VALUE = rep(1:6, 1000000) )
        dt = as.data.table(df)
    })
    #    user  system elapsed 
    #   0.123   0.000   0.123 

    # split PREFIX into new columns
    system.time ({
        dt$PX = as.character(lapply(strsplit(as.character(dt$PREFIX), split=&quot;_&quot;), &quot;[&quot;, 1))
        dt$PY = as.character(lapply(strsplit(as.character(dt$PREFIX), split=&quot;_&quot;), &quot;[&quot;, 2))
    })
    #    user  system elapsed 
    #  33.185   0.000  33.191 

So the `str_split_fixed` method takes about 20X times longer.



Split text string in a data.table columns

I have a survey file in which row are observation and column question.

Here are some [fake data][1] they look like:

    People,Food,Music,People
    P1,Very Bad,Bad,Good
    P2,Good,Good,Very Bad
    P3,Good,Bad,Good
    P4,Good,Very Bad,Very Good
    P5,Bad,Good,Very Good
    P6,Bad,Good,Very Good


My aim is to create this kind of plot with `ggplot2`. 

 - I absolutely **don&#39;t care of the colors, design, etc.**
 - The plot doesn&#39;t correspond to the fake data

![enter image description here][2]


Here are my fake data:

    raw &lt;- read.csv(&quot;http://pastebin.com/raw.php?i=L8cEKcxS&quot;,sep=&quot;,&quot;)
    raw[,2]&lt;-factor(raw[,2],levels=c(&quot;Very Bad&quot;,&quot;Bad&quot;,&quot;Good&quot;,&quot;Very Good&quot;),ordered=FALSE)
    raw[,3]&lt;-factor(raw[,3],levels=c(&quot;Very Bad&quot;,&quot;Bad&quot;,&quot;Good&quot;,&quot;Very Good&quot;),ordered=FALSE)
    raw[,4]&lt;-factor(raw[,4],levels=c(&quot;Very Bad&quot;,&quot;Bad&quot;,&quot;Good&quot;,&quot;Very Good&quot;),ordered=FALSE)


But if I choose Y as count then I&#39;m facing an issue about choosing the X and the Group values... I don&#39;t know if I can succeed without using `reshape2`... I&#39;ve also tired to use reshape with melt function. But I don&#39;t understand how to use it...


  [1]: http://pastebin.com/raw.php?i=L8cEKcxS
  [2]: http://i.stack.imgur.com/yCWRc.png

Grouped bar plot in ggplot

I&#39;m trying to import my dataset in R using `read.table()`:

    Dataset.df &lt;- read.table(&quot;C:\\dataset.txt&quot;, header=TRUE)

But I get the following error message:

    Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,  :
       line 1 did not have 145 elements

What does this mean and how can I fix it?

Issue when importing dataset: `Error in scan(...): line 1 did not have 145 elements`

I&#39;ve been using [Cygwin][1] (for a long time). Specifically, I use it (including gcc/g++) on Win7 for development work. I&#39;ve just recently noticed there now exists a [64-bit version][2]. 

I don&#39;t have a specific need which requires that I make the transition to 64-bit, but I was wondering whether to do it anyway. Is it advisable? What are the pros and cons? Are there known over-arcing issues when making the transition?


  [1]: http://www.cygwin.com/
  [2]: http://cygwin.com/install.html

Is it advisable to switch from Cygwin 32bit to Cygwin 64bit?

I can&#39;t start the `SQL Server browser` from `SQL Service Configuration Manager 2008` version. There are absolutely no options to start the service. It&#39;s disabled as image shown below. How should I start the service again?

![window][1]


  [1]: http://i.stack.imgur.com/8FNXN.png

I cannot start SQL Server browser

I&#39;m trying to compile a 32-bit C application on Ubuntu Server 12.04 LTS 64-bit using gcc 4.8. I&#39;m getting linker error messages about incompatible libraries and `skipping -lgcc`. What do I need to do to get 32 bit apps compiled and linked? 

How to Compile 32-bit Apps on 64-bit Ubuntu?

Running a simple Java program on our production machine, I noticed that this program eats up more 10G virt. I know that virtual memory is not that relevant, but at least I would like to understand why this is needed.

    public class Main {
      public static void main(String[] args) {
            System.out.println(&quot;Hello World!&quot;);
            try {
                    Thread.sleep(10000);
            } catch(InterruptedException e) {
                    /* ignored */
            }
      }
    }

Heres what `top` is saying when i run that little program:

      PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    18764 myuser    20   0 10.2g  20m 8128 S  1.7  0.1   0:00.05 java

Does anyone know why this is happening?

uname -a says:

    Linux m4fxhpsrm1dg 2.6.32-358.18.1.el6.x86_64 #1 SMP Fri Aug 2 17:04:38 EDT 2013 x86_64 x86_64 x86_64 GNU/Linux

On an older 32bit-linux machine the same program consumes only about 1G virt. The old machine has 4GB RAM, the new one 32GB.

A simple &quot;Hello World&quot; needs 10G virtual memory on a 64-bit machine vs 1G at 32-bit?

I&#39;m using Ubuntu Gnome 14.04, and I have Java 8 installed (both the JDK and the JRE).

When I was installing Android Studio everything worked, but a message appeared saying:

&gt;Unable to run mksdcard SDK tool

How can I install Android Studio correctly, or how do I fix this ?

Unable to install Android Studio in Ubuntu

Since Ubuntu 13.10 no longer has ia32-libs I cannot get my android development environment running on a clean install of 13.10.

The error is ~/android-studio/sdk/build-tools/android-4.2.2/aapt&quot;: error=2, No such file or directory

This file does exist and is executable but it is a 32bit executable.

In previous installs I just installed ia32-libs to fix this but this solution no longer works for Ubuntu 13.10.

I have tried solutions proposed by askubuntu questions eg. this one https://askubuntu.com/questions/107230/what-happened-to-the-ia32-libs-package

but it isn&#39;t working for me. 
From that askubuntu.com answer I see I should install separate packages with 

    sudo apt-get install package:i386 

but I don&#39;t know which packages to install to make the android tools work again.

Has anyone else solved this problem and or does anyone have a list of packages which need to be installed for the android tools?

How to make Android&#39;s aapt and adb work on 64-bit Ubuntu without ia32-libs (works for versions 12, 13 and 14)

I&#39;m running Windows 8.1 x64 with Java 7 update 45 x64 (no 32 bit Java installed) on a Surface Pro 2 tablet.

The code below takes 1688ms when the type of i is a long and 109ms when i is an int. Why is long (a 64 bit type) an order of magnitude slower than int on a 64 bit platform with a 64 bit JVM?

My only speculation is that the CPU takes longer to add a 64 bit integer than a 32 bit one, but that seems unlikely. I suspect Haswell doesn&#39;t use ripple-carry adders.

I&#39;m running this in Eclipse Kepler SR1, btw.


    public class Main {
    
        private static long i = Integer.MAX_VALUE;
    
        public static void main(String[] args) {	
            System.out.println(&quot;Starting the loop&quot;);
            long startTime = System.currentTimeMillis();
            while(!decrementAndCheck()){
            }
            long endTime = System.currentTimeMillis();
            System.out.println(&quot;Finished the loop in &quot; + (endTime - startTime) + &quot;ms&quot;);
        }

        private static boolean decrementAndCheck() {
            return --i &lt; 0;
        }

    }


Edit: Here are the results from equivalent C++ code compiled by VS 2013 (below), same system. &lt;del&gt;long: 72265ms int: 74656ms&lt;/del&gt;  Those results were in debug 32 bit mode.

In 64 bit release mode: &lt;del&gt;long: 875ms&lt;/del&gt; long long:  906ms int: 1047ms


This suggests that the result I observed is JVM optimization weirdness rather than CPU limitations.




    #include &quot;stdafx.h&quot;
    #include &quot;iostream&quot;
    #include &quot;windows.h&quot;
    #include &quot;limits.h&quot;

    long long i = INT_MAX;

    using namespace std;


    boolean decrementAndCheck() {
	return --i &lt; 0;
    }


    int _tmain(int argc, _TCHAR* argv[])
    {


	cout &lt;&lt; &quot;Starting the loop&quot; &lt;&lt; endl;

	unsigned long startTime = GetTickCount64();
	while (!decrementAndCheck()){
	}
	unsigned long endTime = GetTickCount64();

	cout &lt;&lt; &quot;Finished the loop in &quot; &lt;&lt; (endTime - startTime) &lt;&lt; &quot;ms&quot; &lt;&lt; endl;



    }


Edit: Just tried this again in Java 8 RTM, no significant change.

Why is long slower than int in x64 Java?

The Windows operating system can be either 32 bit or 64 bit. The **64 bit** version is called **Windows x64** but the **32 bit** version is called **Windows x86**. Why isn&#39;t it called **Windows x32**? What is the reason?

Why is Windows 32-bit called Windows x86 and not Windows x32?

I was trying to measure the difference of using a `for` and a `foreach` when accessing lists of value types and reference types.

I used the following class to do the profiling.

    public static class Benchmarker
    {
        public static void Profile(string description, int iterations, Action func)
        {
            Console.Write(description);

            // Warm up
            func();

            Stopwatch watch = new Stopwatch();

            // Clean up
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();

            watch.Start();
            for (int i = 0; i &lt; iterations; i++)
            {
                func();
            }
            watch.Stop();

            Console.WriteLine(&quot; average time: {0} ms&quot;, watch.Elapsed.TotalMilliseconds / iterations);
        }
    }

I used `double` for my value type.
And I created this &#39;fake class&#39; to test reference types:

    class DoubleWrapper
    {
        public double Value { get; set; }

        public DoubleWrapper(double value)
        {
            Value = value;
        }
    }

Finally I ran this code and compared the time differences.

    static void Main(string[] args)
    {
        int size = 1000000;
        int iterationCount = 100;

        var valueList = new List&lt;double&gt;(size);
        for (int i = 0; i &lt; size; i++) 
            valueList.Add(i);

        var refList = new List&lt;DoubleWrapper&gt;(size);
        for (int i = 0; i &lt; size; i++) 
            refList.Add(new DoubleWrapper(i));

        double dummy;

        Benchmarker.Profile(&quot;valueList for: &quot;, iterationCount, () =&gt;
        {
            double result = 0;
            for (int i = 0; i &lt; valueList.Count; i++)
            {
                 unchecked
                 {
                     var temp = valueList[i];
                     result *= temp;
                     result += temp;
                     result /= temp;
                     result -= temp;
                 }
            }
            dummy = result;
        });

        Benchmarker.Profile(&quot;valueList foreach: &quot;, iterationCount, () =&gt;
        {
            double result = 0;
            foreach (var v in valueList)
            {
                var temp = v;
                result *= temp;
                result += temp;
                result /= temp;
                result -= temp;
            }
            dummy = result;
        });

        Benchmarker.Profile(&quot;refList for: &quot;, iterationCount, () =&gt;
        {
            double result = 0;
            for (int i = 0; i &lt; refList.Count; i++)
            {
                unchecked
                {
                    var temp = refList[i].Value;
                    result *= temp;
                    result += temp;
                    result /= temp;
                    result -= temp;
                }
            }
            dummy = result;
        });

        Benchmarker.Profile(&quot;refList foreach: &quot;, iterationCount, () =&gt;
        {
            double result = 0;
            foreach (var v in refList)
            {
                unchecked
                {
                    var temp = v.Value;
                    result *= temp;
                    result += temp;
                    result /= temp;
                    result -= temp;
                }
            }

            dummy = result;
        });

        SafeExit();
    }

I selected `Release` and `Any CPU` options, ran the program and got the following times:

&lt;!-- language: none --&gt;

    valueList for:  average time: 483,967938 ms
    valueList foreach:  average time: 477,873079 ms
    refList for:  average time: 490,524197 ms
    refList foreach:  average time: 485,659557 ms
    Done!

Then I selected Release and x64 options, ran the program and got the following times:

&lt;!-- language: none --&gt;

    valueList for:  average time: 16,720209 ms
    valueList foreach:  average time: 15,953483 ms
    refList for:  average time: 19,381077 ms
    refList foreach:  average time: 18,636781 ms
    Done!

Why is x64 bit version so much faster? I expected some difference, but not something this big.

I do not have access to other computers. Could you please run this on your machines and tell me the results? I&#39;m using Visual Studio 2015 and I have an Intel [Core&amp;nbsp;i7][1] 930.

Here&#39;s the `SafeExit()` method, so you can compile/run by yourself:

    private static void SafeExit()
    {
        Console.WriteLine(&quot;Done!&quot;);
        Console.ReadLine();
        System.Environment.Exit(1);
    }

As requested, using `double?` instead of my `DoubleWrapper`:

Any CPU

&lt;!-- language: none --&gt;

    valueList for:  average time: 482,98116 ms
    valueList foreach:  average time: 478,837701 ms
    refList for:  average time: 491,075915 ms
    refList foreach:  average time: 483,206072 ms
    Done!

x64

&lt;!-- language: none --&gt;

    valueList for:  average time: 16,393947 ms
    valueList foreach:  average time: 15,87007 ms
    refList for:  average time: 18,267736 ms
    refList foreach:  average time: 16,496038 ms
    Done!

**Last but not least: creating a `x86` profile gives me almost the same results of using `Any CPU`**.

  [1]: https://en.wikipedia.org/wiki/Intel_Core#Core_i7


Content Type	Original Author	Original Content on Stackoverflow
Question	maziar	View Question on Stackoverflow
Solution 1 - R	G. Grothendieck	View Answer on Stackoverflow
Solution 2 - R	IRTFM	View Answer on Stackoverflow
Solution 3 - R	Hong Ooi	View Answer on Stackoverflow
Solution 4 - R	datalifenyc	View Answer on Stackoverflow

How can I know if R is running on 64 bits versus 32?

R Problem Overview

R Solutions

Solution 1 - R

Solution 2 - R

Solution 3 - R

Solution 4 - R

Python psycopg2 not inserting into postgresql table

Is there a way to generate multiple files/classes with intellij code/file templates?

Attributions