Re: Re: Random Matrix of Integers

*To*: mathgroup at smc.vnet.net*Subject*: [mg48615] Re: [mg48612] Re: Random Matrix of Integers*From*: Oleksandr Pavlyk <pavlyk at phys.psu.edu>*Date*: Tue, 8 Jun 2004 00:48:06 -0400 (EDT)*Organization*: Penn State University; Department of Physics*References*: <200406040851.EAA23928@smc.vnet.net> <c9scag$bt6$1@smc.vnet.net> <200406070933.FAA11076@smc.vnet.net>*Reply-to*: pavlyk at phys.psu.edu*Sender*: owner-wri-mathgroup at wolfram.com

Peter Pein wrote: > > Really? > > In[2]:= > Timing[Do[RandomArray[DiscreteUniformDistribution[8], {4, 4}] + 1, > {k, 1, 10000}]] > Timing[Do[Table[Random[Integer, {2, 9}], {4}, {4}], {k, 1, 10000}]] > Out[2]= > {0.22100000000000009*Second, Null} > Out[3]= > {3.4039999999999995*Second, Null} Dear Peter, I can not confirm your timings ratio. On my PC and with my copy of Mathematica 5.0.1 Table[Random[Integer,{2,9}],{4},{4}] consistently outperforms RandomArray. In[37]:= Quit In[8]:= $Version Out[8]= "5.0 for Microsoft Windows (November 18, 2003)" In[1]:= << "Statistics`" In[2]:= Timing[Do[RandomArray[ DiscreteUniformDistribution[8], {4, 4}] + 1, {k, 1, 10000}]] Out[2]= {2.924*Second, Null} In[3]:= Timing[Do[Table[Random[ Integer, {2, 9}], {4}, {4}], {k, 1, 10000}]] Out[3]= {0.601*Second, Null} It occurred to me that we might be using different Mathematica versions, so I ran this code on Solaris Mathematica 4.1 Mathematica 4.1 for Sun Solaris Copyright 1988-2000 Wolfram Research, Inc. -- Terminal graphics initialized -- In[1]:= <<Statistics` In[2]:= Timing[Do[RandomArray[ DiscreteUniformDistribution[8], {4, 4}] + 1, {k, 1, 10000}]] Out[2]= {11.23 Second, Null} In[3]:= Timing[Do[Table[Random[ Integer, {2, 9}], {4}, {4}], {k, 1, 10000}]] Out[3]= {4.88 Second, Null} with essentially the same outcome: Random[Integer,{2,9}] is faster. It makes perfect sense to me that StandardPackage function is slower than the built in one, otherwise it would be wise to make the former built-in. Are your results consistent ? I mean can you reproduce them in the freshly started kernel ? what is your cpu and mathematica version ? Regards, Sasha > "Oleksandr Pavlyk" <pavlyk at phys.psu.edu> schrieb im Newsbeitrag > news:c9scag$bt6$1 at smc.vnet.net... > >>Hi Bruce, >> >>Random is using uniform distribution, so >>the it should be used with RandomArray. >> >>In[1]:= >><< "Statistics`" >>In[11]:= >>RandomArray[ >> DiscreteUniformDistribution[8], {4, 4}] + 1 >>Out[11]= >>{{4, 3, 4, 4}, {7, 2, 2, 6}, >> {5, 2, 7, 4}, {6, 8, 2, 9}} >> >>However note that RandomArray is much slower >> >>In[2]:= >>Timing[Do[RandomArray[ >> DiscreteUniformDistribution[8], {4, 4}] + 1, >> {k, 1, 10000}]] >>Out[2]= >>{3.636*Second, Null} >>In[3]:= >>Timing[Do[Table[Random[ >> Integer, {2, 9}], {4}, >> {4}], {k, 1, 10000}]] >>Out[3]= {0.6609999999999996*Second, Null} >> >>Sasha >> >>

**References**:**Random Matrix of Integers***From:*"Bruce W. Colletti" <bcolletti@compuserve.com>

**Re: Random Matrix of Integers***From:*"Peter Pein" <petsie@arcor.de>