VISAN Color Table Information

VISAN
1

The VISAN reference documentation states the following with relation to the colortable property for WPLOT :

" The color table to associate with the values in dataset.
VISAN will first try to see if the value of this string is equal to one of its built-in predefined color tables: “BlackToWhite”, “WhiteToBlack”, “GreenToRed”, “RedToGreen”, “Cloud”, “Rainbow”, “Ozone”, “Blackbody”, or “Aerosol”.
In all other cases, the string is interpreted as a filename containing a VISAN color table definition."

I can find no reference to the VISAN color table definition in any file or documentation.

Is it possible to import a VISAN color table definition from an external file or export a customized color table to an external file?

2

This indeed is a bit of underdeveloped functionality. Passing a path to a colortable file also doesn’t seem to work.
What will work is:

a = wplot(product)
a.GetColorTable(0).Import("colortable.txt")

And then use something like this for colortable.txt:

ColorTable 1.0
TableSize=256
Name=Custom
NumberOfGradientEdges=3
InterPolationMode=0
0.0 0 0 1.0 1.0
0.5 0 1.0 0.0 1.0
1.0 1.0 0 0 1.0

Make sure to set NumberOfGradientEdges to the number of XRGBA values you provide at the end.

This should hopefully get you going until we properly fix this.

3

Thank you for your prompt reply.

Your solution works for me and gives the functionality that I need.