[Scilab-users] filled contour plot

[Claus Futtrup]

Hi Rafael

Thank you very much for your kind help. The very detailed contourf  works
now. Also thanks for the tip with the colorbar - it looks great. I see how
re-painting with contour2d brings back the contour lines. With the many
colours in the colormap, all lines are blue, which is OK. :-) I guess the
answer is I cannot use a different colormap (or any specific color) for
these lines.

In the last example of contourf you see some black lines. The example
shows how to remove the lines (the last few lines of code) and it appeasr
that feeding a vector of zeros into contourf as the last input parameter
turns these lines on. I wonder why the example uses 0*ones(m) and not
simply zeros(m) ... there are so many strange things wtih example 3, and
the learning curve is much too steep. Like I mentioned before, IMO example
3 is cryptic.

Again, Rafael, thank you for your kind help. I believe the plot is now how
it should be.

Best regards,
Claus

On Sun, Jan 21, 2018 at 9:38 PM, Rafael Guerra <jrafaelbguerra at hotmail.com>
wrote:

> Hi Claus,
>
> Please check code below which produces the plot herein.
> Optionally you can add contours to it.
> However the contour level labels do not seem to display on such log-plots.
> A
> possible contour2d bug?
>
> <http://mailinglists.scilab.org/file/t495698/contourf_colorbar.gif>
>
> //START OF CODE
> frequencies = [200 2000 20000]; // Hz
> angles = [0 30 60 90 120 150 180]; // degrees - convert to radians!
> mag00 = [69.253448 92.163385 87.414209]; // on-axis freq-response
> mag30 = [68.461357 90.569082 76.073549];
> mag60 = [65.842262 90.745621 74.152067];
> mag90 = [59.420658 80.893365 55.975304];
> mag120 = [52.505173 80.795915 44.363582];
> mag150 = [53.829987 59.793715 42.443964];
> mag180 = [55.650341 73.457973 55.608187];
>
> magnitudes = [mag00' mag30' mag60' mag90' mag120' mag150' mag180'];
>
> negative_angles = -angles(2:7);
> neg_angle_magnitudes = magnitudes(:,2:7);
> angles = [angles negative_angles];
> magnitudes = [magnitudes neg_angle_magnitudes];
> [angles idx] = gsort(angles,'g','i');
> magnitudes = magnitudes(:,idx);
>
> clf;
> nz = 40:10:90;
> nz2 = 40:1:90;
> cplot = gcf();
> cplot.color_map= jetcolormap(length(nz2)); // blue = cold, red = hot :-)
> contour2d(frequencies,angles,magnitudes,nz,logflag="ln");
> contourf(frequencies,angles,magnitudes,nz2);
> cplot.children.data_bounds = [200,-180;2e4,180];
> // contour2d(frequencies,angles,magnitudes,nz,logflag="ln");  //
> Optionally
> add contours
> // xset("fpf","%.0f");   // bug? not working for logarithmic axes...
> colorbar(min(magnitudes),max(magnitudes))
> xlabel("frequency [Hz]");
> ylabel("angle (deg)");
> //END OF CODE
>
> Regards,
> Rafael
>
>
>
>
> --
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