access plot colors programmatically

[Jamieg]

Hi all,

When plotting multiple plots on the same axes, Labview automatically assigns each plot a different colour.
How can I programmatically access this colour sequence (an array?) and set it with an array of colours I choose?

Regards,
Jamie

[TCPlomp]

Hi Jamie,

the following code should work:


Ton


Message Edited by TonP on 02-11-2008 07:45 AM

[altenbach]

Use a property node of the graph with two items: (1) active plot (2) plot color.

For example the code shown in the image would change the first three plots to green, red, and yellow respectively by autoindexing over an array of 3 colorbox constants.

Message Edited by altenbach on 02-10-2008 10:51 PM

[devchander]

Use Plot color property node, as shown in the attached vi

[Jamieg]

Hi,
My VI is more flexible in terms of number of plots, see attached example.
When increase the number of plots between runs, errors occur in assigning the colour array.
How can I dynamically program the chart to be ready for any number of plots?
Jamie

[GerdW]

Hi Jamie,

easy solution: first plot the data, then color them! Because: you cannot color more plots than are plotted in the chart...

[Tohatsu]

how many plots can there be maximum?

if you create a "big" array of colors, and let "dimension size" control how many times the loop iterates, you should be fine

you could also create a sub-array with the proper length of colors according to dimension, and let the auto-indexing tunnel set the number of iterations (remove dimension to N), thatway, you can never get "out of bounds" if you have more plots than colors, the drawback however is that the plots above the number of colors in your "big" array will not be assigned speciffic colors.

[Jamieg]

Thanks for the help all.
I've tried Gerd's solution and also one of my own by initialising the history with the right number of plots.
These all work for the small examples provided.
However, when I put them into my larger program of multiple VIs and chart data acquired from a queue, I still get the same errors with invalid active plot inputs.
I really have no idea why the errors occur in the larger program am at a bit of a loss.
Jamie

[GerdW]

Hi Jamie,

so where's the difference between the "small solution" presented here and your "larger program"?

[Eriquito]

Hi Jamie,

I recommend hooking up the Simple Error Handler.vi to your error cluster to pinpoint exactly where the error is occuring in your main VI.  You can then probe the inputs to those property nodes;  that should shed some light on the subject.