Re: [Plplot-general] Simple coloring question

[Arjen M. <arj...@wl...>]

fred wrote:
> 
> Hello,
> 
>  I'm using the wxWidgets binding of plPlot, wxPlot,
> but I think my question is general enough to post
> here. I apologize in advance if this question is
> obvious.
> 
> I have a three data arrays, x[], y[], z[], all of
> equal length.  I would like to plot the x, y arrays
> against each other using z to color the points.  I
> don't think that a contour plot will work here, as the
> z[] values are discontinuous and non-linear in x and
> y.  For those of you who use R, I am basically trying
> to call something like:
> 
> plot( x, y, col = z)
> 
> In plplot, I tried the following:
> 
> for( int i = 0; i < NUM_POINTS; i++ ){
>   myPlot->col( z[i] );
>   myPlot->poin( 1, x[i], y[i], 1 );
> }
> 
> This kind of works, but it is slow and inelegant and
> some of the colors don't seem to display properly.
> Moreover, a continuous color range along the lines
> "Color Map 1" from the documentation would be
> preferable.  I think that I may want to use a shade
> plot, but it is not well documented, and I only want
> to color the individual points.
> 
> Advice?  Suggestions?  Thanks in advance.
> 

I second Alan's advice, but I would like to know what 
makes you think that the code is too slow? After all,
a single call to some more convenient PLplot routine
would have to go through the same loop and I do not
think that is going to be much more efficient -
unless wxWorks is doing an screen update with each
call to myPlot->poin() ...

Regards,

Arjen