ColorScale Precision Adjustment

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Hi,
I was trying to use the colorscale redwhiteblue to indicate Pearson coefficient from -1 to 1. However cannot get the white to spot onto 0, purpose was to show positive values in red and negative values in blue. Any help?
Greatly appreciated!
[quote=mwpro]Hi,
I was trying to use the colorscale redwhiteblue to indicate Pearson coefficient from -1 to 1. However cannot get the white to spot onto 0, purpose was to show positive values in red and negative values in blue. Any help?
Greatly appreciated![/quote]

When you set the colorscale, are you specifying min and max to be -1 and 1? The default is to use the min and max of the wave and this might cause 0 to not be pure white if your min and max are inside of -1 to 1.

June 3, 2018 at 12:29 pm - Permalink
[quote=sjr51][quote=mwpro]Hi,
I was trying to use the colorscale redwhiteblue to indicate Pearson coefficient from -1 to 1. However cannot get the white to spot onto 0, purpose was to show positive values in red and negative values in blue. Any help?
Greatly appreciated![/quote]

When you set the colorscale, are you specifying min and max to be -1 and 1? The default is to use the min and max of the wave and this might cause 0 to not be pure white if your min and max are inside of -1 to 1.[/quote]

yes , I did specify the min and max to be -1 and 1, and still 0 is not pure white, a little puzzled...

June 3, 2018 at 03:02 pm - Permalink
Poorly adjusted colors on screen/printer?
Could you post a minimal example and a screenshot?

HJ

June 3, 2018 at 11:31 pm - Permalink

 
•make /N=(101,100) test
•setscale x, -1,1, "", test
•test=x
•newimage test
•ModifyImage test ctab= {-1,1,RedWhiteBlue,0}

gives a pure white around 0. (Pipette tool unfortunately not visible in the screen shot.)

HJ
RWB.jpg (17.56 KB)

June 4, 2018 at 05:32 am - Permalink