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Re: Could someone help optimize this for Mathematica 9?

• To: mathgroup at smc.vnet.net
• Subject: [mg128943] Re: Could someone help optimize this for Mathematica 9?
• From: Brett Champion <brettc at wolfram.com>
• Date: Wed, 5 Dec 2012 03:11:38 -0500 (EST)
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On Dec 4, 2012, at 3:14 AM, "McHale, Paul" <Paul.McHale at excelitas.com> 
wrote:

> We have a strong need to view large numbers of data points.  
Mathematica 8 was excellent at this.  The following code executed under 
both 8 and 9 (Windows):
>
> Mathematica 8: Less than 0.5 seconds
> Mathematica 9: Greater than 4 seconds
>
> mNumberSamples=100000;
> mFrequency=10;
> m=Table[{t/mNumberSamples ,Sin[t/mNumberSamples mFrequency*2 
\[Pi]]}*1.0,{t,1,mNumberSamples}];mStartTime=SessionTime[];
> ListLinePlot[m]
> mStopTime=SessionTime[];
> StringForm["Elapsed time = ``", N[mStopTime-mStartTime]]
>
> I have tried the code on a slower mac laptop (version 9 only) and had 
the same slower results.  Any input welcome as this functionality is 
extremely important to us.
>

This was caused by an oversight when updating ListLinePlot to support 
units for V9.  The fastest workaround I've found so far is to use:

m = Developer`ToPackedArray[ Table[...] ];

Depending on what options you're using to generate the plots, it may 
also be slightly faster to use ListPlot[m, Joined->True] instead of 
ListLinePlot[m].

Brett Champion
Wolfram Research

• References:
  • Could someone help optimize this for Mathematica 9?
    • From: "McHale, Paul" <Paul.McHale@excelitas.com>