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