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Problem with colors in contour plot

5 messages · Loukia Spineli, Rui Barradas, Jim Lemon

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Dear R users,

I have a 51 by 51 matrix of p-values (named as pvalue_MA). I want to
present graphically this matrix in a plot (filled contour plot) where both
axes represent probabilities. I have also added a grid in this plot. I want
to highlight in white the cells of the grid that represent p-values smaller
than the (common) significance threshold, 0.05. The code from this plot is
colored in blue (I had to copy-pasted all this code in order to reach to
the plot). I suspect that the "problem" might be in the col parameter of
the filled.contour function. Honestly, I cannot understand why the plot
appears to be completely white!! I checked the values of my variable and it
has a great range from 0 to 1.
Any suggestion/ comment would really help me to move on with my project.

All the best,

Loukia
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The contpour plot is very impressive!!! The contour plot I want to display
should have only 2 colors: white a grey. I have created this plot for only
one trial (see, ppts) and now I am attempting to do the same for many
trials.
On Thu, Oct 4, 2012 at 3:51 PM, Rui Barradas <ruipbarradas at sapo.pt> wrote:

            
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On 10/04/2012 10:25 PM, Loukia Spineli wrote:
Hi Loukia,
Do you really need a contour plot for this?

pvals<-matrix(runif(2601),nrow=51)
library(plotrix)
pcols<-ifelse(pvals<=0.05,"white","gray")
color2D.matplot(pvals,cellcolors=pcols)

Jim