| Re: Frustrated by 2 Data Plotting problems [message #76390 is a reply to message #76267] |
Tue, 31 May 2011 09:28   |
pgrigis
Messages: 436
Registered: September 2007
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Senior Member |
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Here's an example where mindlessly plotting
points may lead to wrong conclusions:
x=randomn(seed,4*10.0^6)
y=randomn(seed,4*10.0^6)
plot,x,y,xrange=[-8,8],yrange=[-8,8],/iso,psym=3,/xst,/yst
The plot seems to indicate that the distribution
of the points within 3 units from (0,0) is uniform,
which is not the case as the points are drawn from
a normal distribution - this is just an artifact from
the overlap of the points.
Ciao,
Paolo
On May 28, 11:50 am, David Fanning <n...@idlcoyote.com> wrote:
> David Fanning writes:
>> But this sort of proves my point. If I run your program
>> with 1 percent of the points, the "visualization" doesn't
>> change in any material way, but the time is reduced by
>> a factor of 1000.
>
> Sorry. Factor of 100. While I was writing this I was
> momentarily distracted by both a Lazuli Bunting and
> a Western Tanager showing up at the backyard feeder
> at the same time! Two rare and beautiful birds on the
> same day is unbelievable, but two on the same feeder
> is a miracle!
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.idlcoyote.com/
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
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