Changing a 2D color wave from red, green, blue to red, yellow, blue: (0, 65535,0) = Green to --> (0,65535,0)=Yellow

I think you solution could be something like this:
x=1, y=0: Red=(65535,0,0)
x=0, y=1: Blue=(0,0,65535)
x=0, y=0: Yellow=(65535,65535,0)
x=1, y=1: Magenta=(65535,0,65535)

So you can set your colours using an interpolation according to your x,y data:
colour(x,y)=(R,G,B) where

R=(x+y<1) ? 65535*(1-y) : 65535*x
G=(y>x) ? 65535*(1-y) : 65535*(1-x)
B=65535*y

Hope this helps!
Kurt

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Hej Kurt,

thanks for the quick reply, but I don't think this will work. I played around along the line you suggested, but I could not come up with something that would show the right color.

I will try to be a bit more specific with my data. The problem with the interpolation is that I have x,y,and z and x+y+z=1.

The x,y and z values correspond to intensity of fluorecent proteins (GFP variants) that are expressed in cells in relation to each other. x=1 means that the cells are only red. x=0.25, y=0.25, z=0.5 means that the cells are equally strong in red and blue, but that yellow is twice as strong as either of them.

I only need to plot x vs y because it shows the z value indirectly (x=0 and y=0 means z=1). I have a attached some example plots.

I scale my data points (range 0 to 1) to 65535 and put them into the color wave function that has 3 columns with the first corresponding to red, second to green and 3rd to blue.

e.g.

x z y
1 0 0 --> (65535,0,0) --> red
0 1 0 --> (0,65535,0) --> green
0 0 1 --> (0,0,65535) --> blue
0.5 0 0.5 --> (32767,0,32767) --> something between red and blue

The problem with showing yellow is that I have to transform:
x z y
0 1 0 --> (65535,65535,0) --> Yellow

But I still need to keep:
x z y
1 0 0 --> (65535,0,0) --> Red

All the different yellow shades need to have 65535 in the first column.

So I don't see how I can simply adjust the x values.

Every recalculation I did lead to some wrong mixture of red, yellow or blue.


I wondered if there is a different possibility of doing this like linking a " red to yellow" color table to the x values and a "yellow to blue" color table to the y values. So some kind of f(x,y) instead of f(z) for the color scaling a scatterplot.

But, Kurt, thanks for trying to help nonetheless ... I will think about the scaling a bit more.

Have a good evening,

Topaz

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Hej Kurt,

you were right with the rescaling ... I found a solution now, but it looks a bit different.

R=(1-y)*65535
G=(1-x-y)*65535
B=y*65535

Just wanted to say thanks!

cheers mate,

Topaz

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Hi Topaz,
Glad you have a solution now.
Regards,
Kurt

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