Is there any possible to get the color info after using PlotScaledIntensity?

[mike.Cheong]

Dear Sir/Madam:

I would like to know if it is possible to get the color info after using the PlotScaledIntensity function? If can't, any method I can get it?

If using the Plotpoint I can use the following to get the color info, however when I use the PlotScaledIntensity, I can't get the color info what I got? 

/* Figure out which plot and which point the Cursor is over */
    GetGraphCursorIndex (panelSpecGrap, SPECTGRAH_GRAPH, 1, &plothandle[0], &index[0]);
    GetGraphCursorIndex (panelSpecGrap, SPECTGRAH_GRAPH, 2, &plothandle[1], &index[1]);
    
    if (plothandle[0] == -1 || plothandle[1] == -1)
     break;
    /* Get the plot color associated with the plothandle returned above */
    GetPlotAttribute (panelSpecGrap, SPECTGRAH_GRAPH, plothandle[0], ATTR_TRACE_COLOR, &color[0]);
    GetPlotAttribute (panelSpecGrap, SPECTGRAH_GRAPH, plothandle[1], ATTR_TRACE_COLOR, &color[1]);

Regards,

Mike Cheong

[Jack J.]

There is no built in method for getting the color of a certian Z-value in an intensity plot. This is differenet from a regular plot because in a regular plot, the color of the data is user defined only and is the same for the entire plot whereas in an intensity plot, the color differs for each element in a plot and is dependent on the value of the element, the min and max values of the plot and the high and low color selected.

You can however, calculate the color of any particular Z value. by interpolating it between the two closest defined points as defined in the ColorMapEntry[] array. If that array has a constant slope, then you can simply take the R, G, B values of the low and high color and find the value of the Z colors based on the max and min Z values.

For example, if your Low RGB is 0, 50, 100 and your high is 200, 200, 200 and your min Z is 5 and max Z is 15. Then a Z of 10 will have RGB of 100, 125, 150.

Regards,

Jack J.
Applications Engineer
National Instruments