Hi all I'm plotting colored contour maps using filled.contour. My levels are very unevenly spaced, with, say, high resolution in the small numbers but ranges that can be an order of magnitude or two larger in absolute value compared to where the action takes place. Aside from transforming the data, is there a way to control the color spacing in the key to the right of the map? Right now I get most of the key length taken up by a couple of colors and the rest all squeezed into thin slices, which also creates a problem with the fourth axis labels getting drawn on top of one another. thank you very much in advance Claudia
spacing of color key in filled.contour
3 messages · Claudia Tebaldi, Jim Lemon, Clint Bowman
On 01/20/2011 09:19 AM, claudia tebaldi wrote:
Hi all I'm plotting colored contour maps using filled.contour. My levels are very unevenly spaced, with, say, high resolution in the small numbers but ranges that can be an order of magnitude or two larger in absolute value compared to where the action takes place. Aside from transforming the data, is there a way to control the color spacing in the key to the right of the map? Right now I get most of the key length taken up by a couple of colors and the rest all squeezed into thin slices, which also creates a problem with the fourth axis labels getting drawn on top of one another.
Hi Claudia, You can roll your own color key with the color.legend function in plotrix. Just specify the colors you want in "rect.col" and the labels in "legend". Jim
I've gotten good results using the sine function to map colors. For example, when plotting x, map the range(x) to (-pi/2,pi/2) which the sine will transform to (-1,1), then add 1 and multiply by half the desired number of colors. Now the integer values will pick the colors and give a pleasing display. If the "squeeze" is taking place only over one of the tails (which sounds like your case) map the range from (0,pi/2) or (-pi/2,0) and make the necessary scaling adjustments to cover the number of colors desired. Essentially, you are transforming the color mapping instead of transforming your data. Clint
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On Thu, 20 Jan 2011, Jim Lemon wrote:
> On 01/20/2011 09:19 AM, claudia tebaldi wrote:
>> Hi all
>>
>>
>> I'm plotting colored contour maps using filled.contour. My levels
>> are very unevenly spaced, with, say, high resolution in the small
>> numbers but ranges that can be an order of magnitude or two larger in
>> absolute value compared to where the action takes place. Aside from
>> transforming the data, is there a way to control the color spacing in
>> the key to the right of the map? Right now I get most of the key
>> length taken up by a couple of colors and the rest all squeezed into
>> thin slices, which also creates a problem with the fourth axis labels
>> getting drawn on top of one another.
>>
> Hi Claudia,
> You can roll your own color key with the color.legend function in plotrix.
> Just specify the colors you want in "rect.col" and the labels in "legend".
>
> Jim
>
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