RE: Re: Making a large matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg14881] RE: [mg14844] Re: [mg14832] Making a large matrix*From*: "Jean-Marie THOMAS" <jmthomas at agat.net>*Date*: Mon, 23 Nov 1998 10:11:59 -0500*Sender*: owner-wri-mathgroup at wolfram.com

What about: t1=Timing[Table[Table[Random[],{1000}],{1000}];]; t2=Timing[Table[Random[],{1000},{1000}];]; {26.278 Second,22.091 Second} The second form is nevertheless a little faster! **************************************** Jean-Marie THOMAS mailto:jmthomas at agat.net Conseil et Audit en Ingenierie de Calcul Strasbourg, France http://www.agat.net **************************************** -----Original Message----- From: Clemens Frey [mailto:clemens.frey at bitoek.uni-bayreuth.de] To: mathgroup at smc.vnet.net Subject: [mg14881] [mg14844] Re: [mg14832] Making a large matrix > Date: Wed, 18 Nov 1998 01:29:37 -0500 > From: "Ersek, Ted R" <ErsekTR at navair.navy.mil> > To: mathgroup at smc.vnet.net > Subject: [mg14881] [mg14844] [mg14832] Making a large matrix > > Consider the timing experiments below for making a large matrix of > random real numbers. > > In[1]:= > Table[Table[Random[],{1000}],{500}];//Timing Out[1]= > {17.47 Second,Null} > > In[2]:= > Table[Range[Random[],1000],{500}];//Timing Out[2]= > {9.56 Second,Null} Ted, I don't think that these timings are comparable since the things they do are different. This produces 10 random numbers between 0 and 1: Table[Random[],{10}] {0.132055,0.668036,0.527731,0.35746,0.0925349, 0.0799395,0.946264,0.037643, 0.224293,0.827124} ...but this produces 10 successive numbers, starting at a random number between 0 and 1 : Range[Random[],10] {0.530468,1.53047,2.53047,3.53047,4.53047, 5.53047,6.53047,7.53047,8.53047, 9.53047} Clemens