adjusting levelplot color scale to data
On Nov 6, 2011, at 10:08 PM, Lanna Jin wrote:
Hi guys, I have a matrix with values varying from approximately -0.7 to 0.33 that I want to create a heatmap/levelplot with. When I execute the levelplot function for my matrix, I end up getting colors that are adjusted to the max and min rather than around 0. In other words, ideally I would like to have a color ramp that goes from red (negative number), to white (0), to blue (positive); however, right now the value 0 is in the blue. Any insight on how to address this problem?
?levelplot # which leads to" ?level.colors # which in turn leads to: ? colorRamp levelplot(as.matrix(dat), at=seq( -.8, .4, length=31), col=color.palette(30) ) And next time, please post the output of dput rather than a mangled print() output.
David. > > Thanks in advance! > > example... > my matrix "y" looks something like this > A B C > D E > row1 -0.5046406 -0.021579587 -0.4419101 -0.2999195330 > -0.4845047 > row2 -0.3070091 -0.059065936 0.3329806 -0.0519335420 > -0.5766368 > row3 -0.7271707 0.073282855 -0.3181990 -0.2485017700 > -0.5732781 > row4 0.3329806 -0.017762750 -0.1513197 -0.1016354970 > 0.2528442 > > levelplot(y) yields a color scale from red (-0.8 to 0.2) to blue > (0.2 to > 0.4) > I'd want the color scale to be from red (-0.8 to 0) to blue (0 to 0.4) > > > > ----- > Lanna > -- > View this message in context: http://r.789695.n4.nabble.com/adjusting-levelplot-color-scale-to-data-tp3997342p3997342.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. David Winsemius, MD West Hartford, CT