Re: populate a list with random numbers from normal distribution?
- To: mathgroup at smc.vnet.net
- Subject: [mg49924] Re: [mg49855] populate a list with random numbers from normal distribution?
- From: sean kim <sean_incali at yahoo.com>
- Date: Fri, 6 Aug 2004 03:09:44 -0400 (EDT)
- Reply-to: sean_incali01 at yahoo.com
- Sender: owner-wri-mathgroup at wolfram.com
hi Bob I want to pick integers because of the issues addressed in this group. I've heard that Random Integers are better because it uses wolfram's CA. Problem i can't figure out is How to pick random integers in a Range from a given distribution, say normal. Now i can use, Needs["Statistics`ContinuousDistributions`"] NormalDistribution[50000, 25000] and then sample... RandomArray[l1, 1000]; just as many have sugested, but if I do that, I'm not picking froma range. I even get negative numbers. this is demonstrated well by listploting as wolfgang suggested. ListPlot[RandomArray[l1, 1000]] isn't there a way to pick integers in a given range AND from a distribution? any insights will be thoroughly appreciated. sean --- Bob Hanlon <hanlonr at cox.net> wrote: > Needs["Statistics`ContinuousDistributions`"]; > > data=RandomArray[NormalDistribution[50000,25000],{1000}]; > > #[data]& /@ {Mean, Variance, StandardDeviation} // N > > {49212.297808892145, 6.388327485991619*^8, > 25275.140921450107} > > Since you seem to want Integers > > data=Round /@ data; > > #[data]& /@ {Mean, Variance, StandardDeviation} //N > > {49212.299, 6.388324440996987*^8, > 25275.134897754724} > > > Bob Hanlon > > > > > From: sean_incali at yahoo.com (sean kim) To: mathgroup at smc.vnet.net > > Date: 2004/08/04 Wed AM 10:46:33 EDT > > To: mathgroup at smc.vnet.net > > Subject: [mg49924] [mg49855] populate a list with random > numbers from normal > distribution? > > > > hello group. > > > > I looked at the help browser but i can't figure > this out. I weant to > > make a list of random numbers sampled from a > normal distribution > > > > In[90]:= > Needs["Statistics`ContinuousDistributions`"] > > > > l1 = Table[Random[NormalDistribution[50000,25000], > Integer, {10000, > > 99999}], {1000}]; > > > > Variance[l1]//N > > StandardDeviation[l1]//N > > > > > > From In[90]:= > > Random::"randt": > > Type specification NormalDistribution[50000, > 25000] in > > <<1>> should be Real, Integer, or Complex. > > > > Out[92]= > > 0. > > Out[93]= > > 0. > > > > thanks in advance for any insights > > > > sean > > > > > > __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail