[R] Problem with colors in contour plot

[Jim Lemon]

On 10/04/2012 10:25 PM, Loukia Spineli wrote:
> 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.
>
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