Thanks for the suggestion. I still could not figure out how to use the function to do my job. What's important in my job is that I have to map white color to value 0, and then form a bue gradient for negative values, and red gradient for positive values. The data matrix I have is not symmetric aound 0, say 0 is at the 18 percentile, and values range from -10 to 30. How exactly I could do my job? Bear with me, I am new to color, I don't quite understand how the image function map the number is the data matrix to the colors defined in the col argument.
Thanks --- Thomas Lumley <[EMAIL PROTECTED]> wrote: > On Wed, 3 Aug 2005, array chip wrote: > > > Hi, I have a matrix with both positive and > negative > > numbers, I would like to use image() to draw a > > heatmap. How can I can design a palette (or is > there a > > function already available) that treat negative > > numbers in a blue gradient and positive numbers in > a > > red gradient and treat 0 as white? > > > > ?colorRampPalette > > -thomas > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
