ColorScale Precision Adjustment

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Sun, 06/03/2018 - 11:20 am

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!
mwpro wrote:
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!


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

sjr51 wrote:
mwpro wrote:
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!


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.


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

June 4, 2018 at 05:32 am - Permalink