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Re: Random number Newbie Question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg37894] Re: Random number Newbie Question
  • From: Marc Heusser <marc.heusser at CHEERSheusser.comMERCIALSPAMMERS.invalid>
  • Date: Sun, 17 Nov 2002 06:44:42 -0500 (EST)
  • References: <ar4o2t$5at$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

In article <ar4o2t$5at$1 at smc.vnet.net>,
 doofusmaximus at hotmail.com (Hugh McBride) wrote:

> Something which is probably obvivous to the casual observer 
>  but not me ... 
>  Can someone tell me how to get a numerical value for 
>  from a NormalDistribution[0,1]  
> 
>  Random only returns a random value between 0 & 1
> 


This loads the package which defines continuous statistical 
distributions.
In[1]:= <<Statistics`ContinuousDistributions`
This represents a normal distribution with mean zero and unit variance. 
In[2]:= ndist = NormalDistribution[0, 1]
Out[2]= NormalDistribution[0,1]
Here is a symbolic result for the cumulative distribution function of 
the normal distribution. 
In[3]:= CDF[ndist, x]Out[3]= \!\(1\/2\ \((1 + Erf[x\/\@2])\)\)
This gives the value of x at which the cdf of the normal distribution 
reaches the value 0.9. 
In[4]:= Quantile[ndist, 0.9] // NOut[4]= 1.28155
Here is a list of five normal\[Hyphen]distributed pseudorandom numbers. 
In[5]:= Table[ Random[ndist], {5} ]Out[5]= 
{-1.63994,0.987641,-0.475946,-0.598517,-1.04913}

Is this what you're looking for?

HTH

Marc

-- 
Marc Heusser
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