`nextGaussian()` will draw samples from a normal distribution with mean 0 and std-deviation 1, so if you want mean 1 hour and std-deviation 15 minutes you&#39;ll need to call it as `nextGaussian()*15+60`.

From the [docs for `Random.nextGaussian()`](https://docs.oracle.com/javase/8/docs/api/java/util/Random.html#nextGaussian--):

&gt; Returns:  
&gt; the next pseudorandom, Gaussian (&quot;normally&quot;) distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator&#39;s sequence

I suggest you to use apache math: http://commons.apache.org/math/ , look here for more information: http://commons.apache.org/math/userguide/stat.html

I&#39;ve been experimenting and find that I like redefining Object&#39;s `to_s` methods. 

Is this a bad idea or is it good practice?

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I&#39;m trying to simulate the arrival of fans to a stadium. The system itself, I believe it won&#39;t be a problem, but, the arrival of the fans follows a normal distribution. 

My problem is:

I have a certain time for the arrival like 100 minutes and 1000 fans, and I need to generate arrivals of Fans at a time following that distribution like -&gt; fan x arrived at 25 minutes, fan y arrived at 54 minutes, and so on.

How can I generate these random numbers following a normal distribution?

I&#39;m doing this in Java and found the `nextGaussian()` method in the [Random class][1], but I&#39;m not sure how to use this in my situation.

Can someone please enlighten me?

  [1]: http://docs.oracle.com/javase/6/docs/api/index.html?java/util/Random.html

Java normal distribution

I'm trying to simulate the arrival of fans to a stadium. The system itself, I believe it won't be a problem, but, the arrival of the fans follows a normal distribution.
My problem is:
I have a certain time for the arrival like 100 minutes and 1000 fans, and I need to generate arrivals of Fans at a time following that distribution like -> fan x arrived at 25 minutes, fan y arrived at 54 minutes, and so on.
How can I generate these random numbers following a normal distribution?
I'm doing this in Java and found the <code>nextGaussian()</code> method in the <a href="http://docs.oracle.com/javase/6/docs/api/index.html?java/util/Random.html" target="_blank" rel="noopener noreferrer">Random class</a>, but I'm not sure how to use this in my situation.
Can someone please enlighten me?

I have a variable like that:

    List&lt;Double&gt; frameList =  new ArrayList&lt;Double&gt;();
    
    /* Double elements has added to frameList */

How can I have a new variable has a type of `double[]` from that variable in Java with high performance?

How to cast from List&lt;Double&gt; to double[] in Java?

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In Java, I am trying to return all regex matches to an array but it seems that you can only check whether the pattern matches something or not (boolean).

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Has anyone ever found a single JVM document listing default `-Xss` values for various versions of the Oracle JVM, and for different OS&#39;s?

I&#39;ve been able to find this table in the [jrockit docs][1], but that&#39;s not helpful for those using the &quot;normal&quot; Oracle JVM.

I do appreciate that the `-Xss` value will vary per OS (and JVM version), so maybe there&#39;s no one document that lists all recent combinations. But if any readers here know of any individual documents that list at least just the default `-Xss` value for *each* JVM version (or at least 1.6 and 1.5), or even if only for *some* OS&#39;s, that would be a great start. I&#39;m especially interested in the default for Windows.

I&#39;ll add that the reason this is valuable is that often we see people recommend (wrongly, I think) that someone can solve a problem by changing the `-Xss` value. But if you don&#39;t know your default, then there&#39;s no way to know if you&#39;re raising or lowering the value by whatever change someone recommends. They don&#39;t generally indicate the version/OS they&#39;re on, so it&#39;s a crapshoot whether their suggestion will &quot;help&quot; you.

Even better than some documentation, if anyone knows a way to query the JVM to get the current value, whether from the command line or via an API call, that would be even more valuable. Thanks.

&gt; **Update: I have added [an answer of my own][2] that summarizes the various suggestions and points to a current resource (in early 2021)
&gt; indicating the answer, including what I learned about the `-Xss` value
&gt; in Windows.**

[1]: http://download.oracle.com/docs/cd/E13150_01/jrockit_jvm/jrockit/jrdocs/refman/optionX.html#wp1000929
[2]:
https://stackoverflow.com/a/66497611/90802

Where can I find default -Xss (stack size) value for Oracle JVM?

Well, I&#39;ve tried to understand and read what could cause it but I just can&#39;t get it:

I have this somewhere in my code:

     try{
     ..
     m.invoke(testObject);
     ..
     } catch(AssertionError e){
     ...
     } catch(Exception e){
     ..
     }

 Thing is that, when it tries to invoke some method it throws
 `InvocationTargetException` instead of some other expected exception (specifically `ArrayIndexOutOfBoundsException`).
 As I actually know what method is invoked I went straight to this method code and added a try-catch block for the line that suppose to throw  `ArrayIndexOutOfBoundsException` and it really threw `ArrayIndexOutOfBoundsException` as expected. Yet when going up it
 somehow changes to `InvocationTargetException` and in the code above `catch(Exception e)` 
 e is `InvocationTargetException` and not `ArrayIndexOutOfBoundsException`
 as expected.


 What could cause such a behavior or how can I check such a thing?

What could cause java.lang.reflect.InvocationTargetException?

Here&#39;s what I&#39;m using. The token doesn&#39;t necessarily have to be heard to guess, it&#39;s more like a short url identifier than anything else, and I want to keep it short. I&#39;ve followed some examples I&#39;ve found online and in the event of a collision, _I think_ the code below will recreate the token, but I&#39;m not real sure. I&#39;m curious to see better suggestions, though, as this feels a little rough around the edges.

    def self.create_token
        random_number = SecureRandom.hex(3)
        &quot;1X#{random_number}&quot;
        
        while Tracker.find_by_token(&quot;1X#{random_number}&quot;) != nil
          random_number = SecureRandom.hex(3)
          &quot;1X#{random_number}&quot;
        end
        &quot;1X#{random_number}&quot;
      end

My database column for the token is a unique index and I&#39;m also using `validates_uniqueness_of :token` on the model, but because these are created in batches automatically based on a user&#39;s actions in the app (they place an order and buy the tokens, essentially), it&#39;s not feasible to have the app throw an error.

I could also, I guess, to reduce the chance of collisions, append another string at the end, something generated based on the time or something like that, but I don&#39;t want the token to get too long.

Best way to create unique token in Rails?

I want to generate random number in a specific range. (Ex. Range Between 65 to 80)

I try as per below code, but it is not very use full. It also returns the value greater then max. value(greater then 80). 

    Random r = new Random();
    int i1 = (r.nextInt(80) + 65);

How can I generate random number between a range?


How can I generate random number in specific range in Android?

`randrange(start, stop)` only takes integer arguments. So how would I get a random number between two float values?

How to get a random number between a float range?

I am trying to generate a random password in php. 

However I am getting all &#39;a&#39;s and the return type is of type array and I would like it to be a string. Any ideas on how to correct the code?

Thanks.

    function randomPassword() {
        $alphabet = &quot;abcdefghijklmnopqrstuwxyzABCDEFGHIJKLMNOPQRSTUWXYZ0123456789&quot;;
        for ($i = 0; $i &lt; 8; $i++) {
            $n = rand(0, count($alphabet)-1);
            $pass[$i] = $alphabet[$n];
        }
        return $pass;
    }

Generating a random password in php

I want to produce 100 random numbers with normal distribution (with &#181;=10, σ=7) and then draw a quantity diagram for these numbers.

How can I produce random numbers with a specific distribution in Excel 2010?

One more question:

When I produce, for example, 20 random numbers with `RANDBETWEEN(Bottom,Top)`, the numbers change every time the sheet recalculates. How can I keep this from happening?

Generating random numbers with normal distribution in Excel

Can someone please help me fill in the following function in R:

    #data is a single vector of decimal values
    normally.distributed &lt;- function(data) {
    if(data is normal)
    return(TRUE)
    else
    return(NO)
    }

Seeing if data is normally distributed in R

How do I calculate the inverse of the cumulative distribution function (CDF) of the normal distribution in Python?

Which library should I use? Possibly scipy?  


Content Type	Original Author	Original Content on Stackoverflow
Question	Henrique Gonçalves	View Question on Stackoverflow
Solution 1 - Java	ratchet freak	View Answer on Stackoverflow
Solution 2 - Java	Pih	View Answer on Stackoverflow

Java normal distribution

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Equivalent of ERD for MongoDB?

Is overriding to_s methods in Ruby bad?

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