There color wheel only works for complex, and there's currently no way to pass an arbitrary color map. We realize how annoying this is, though, and a future version of our surface viewer won't have this limitation.

On Fri, 2007-03-23 at 16:38 -0500, Greg Appelbaum wrote:

Thanks for the info Kevin. The angle function is quite revealing. As it happens I am looking at EEG data, which likely wasn't in mind in the functional development of FreeSurfer.

Might I also ask if you (the general FreeSurfer 'you') know if it's possible to pass a 'wheel' scale bar to non-complex data? Or generally how to pass in an arbitrary color map?

Thanks again

Greg

On 3/22/07 4:27 PM, "Kevin Teich" kteich@nmr.mgh.harvard.edu wrote:

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I am trying to display phase information on the cortical surface using tksurfer, but am running into problems with the scale bar. Specifically when plotting scalar values using a complex color scale (e.g. RYGB Wheel), I am getting nice looking (continulus) cortical maps, with the correct scale values, but the color bar is showing up inconsistent (two colors). Is there any way to correct this problem, or access the actual color values being projected to the cortical mesh?

Unfortunately, the scale bar isn't really meant to be used with the complex color wheel. There is no way to get a nice legend for the color wheel. However, if you select View->Information->Angle, you can see the actual value that is being passed into the color function, so you can mouseover a color on the surface and see what value is mapped to it. I know it's not great, but maybe it will help a bit.