MathGroup Archive 2005

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Vectorization

  • To: mathgroup at smc.vnet.net
  • Subject: [mg60623] Vectorization
  • From: "Marcelo Mayall" <mmayall at bol.com.br>
  • Date: Thu, 22 Sep 2005 02:08:17 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

It's possible to initialize a vector starting from an elementary functions:

In[1]:=
Table[Sin[Random[]],{10000000}]//Timing//First

Out[1]=
3.203 Second

The same problem can be done a bit more efficiently if the elementary function is applied to the numerical vector:

In[2]:=
Sin[Table[Random[],{10000000}]]//Timing//First

Out[2]=
1.969 Second

But why the tendency is opposed when the numbers are complex ? Is this a bug ?

In[3]:=
Table[Sin[I Random[]],{1000000}]//Timing//First
Sin[Table[I Random[],{1000000}]]//Timing//First

Out[3]=
2.484 Second

Out[4]=
2.656 Second


Thanks,

Marcelo Mayall


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