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Re: Object graphics color scattergram

Jeffrey R. Hall (jeffrey.r.hall@jpl.nasa.gov) writes:
> In IDL object graphics, how does one do a scatter plot where 
> the points are colored by some set of values?  Here is an 
> example using direct graphics:
> seedx		= !pi
> seedy		= !pi ^ 2
> x		= BYTSCL(RANDOMU(seedx, 100, GAMMA=1))/255.0
> y		= BYTSCL(RANDOMN(seedy, 100, GAMMA=1))/255.0
> z		= BYTE( x * 255 )
> I have tried IDLgrPlot with and w/o IDLgrSymbol, and also 
> IDLgrPolyline.  Lines can be colored, even faded from one 
> vertex to the next.  But if the lines are omitted then no 
> points are drawn, and if IDLgrSymbol is used then they are 
> all the same color.
> Plus, I need this to be in 24 bit color rather than PSEUDO=8.

I think you just didn't happen onto the correct sequence
of polylines and symbols. Here is an example of an
object graphics scatterplot that I cobbled together
some time ago from my SIMPLE_SURFACE code.




David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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