[R] levelplot/heatmap question

[Jim Lemon]

cerman at u.washington.edu wrote:
> Hello!
> I have data containing a large number of probabilities (about 60) of 
> nonzero coefficients to predict 10 different independent variables (in 
> 10 different BMA models). i've arranged these probabilities in a 
> matrix like so:
>
>  (IV1)    (IV2)    (IV3)  ...
>  p(b0)    p(b0)    p(b0)
>  p(b1)    p(b1)    p(b1)
>  p(b2)    p(b2)    p(b2)
> ...
>
>
> where p(b1) for independent variable 1 is p(b1 != 0) (given model 
> uncertainty - using the BMA package). i've also set it so that if the 
> coefficient is negative, the probability is listed as negative (to be 
> able to distinguish between significant positive and negative effects 
> by color).
>
> i'd like to create a plot which is a 10x60 grid of rectangles, where 
> each rectangle is colored according to its probability of being 
> nonzero (preferably white would correspond to a zero probability). 
> i've looked into levelplot, heatmap, and image, and cant seem to get 
> exactly what im looking for.
>
> heatmap gives me problems in that the output is inconsistent with the 
> data - among other things, the first and last rows do not seem to show 
> up (they are just white, despite clearly nonzero probabilities).  even 
> if i do not use the dendrogram (Rowv and Colv set to NA), i still seem 
> to have an issue with a probability in a given row not corresponding 
> to the same color as the same probability in a different row.
>
> levelplot seems to do exactly what i want it to do, except that i cant 
> find a way to label the individual columns and rows, which I really need
>
> any ideas how to obtain the graph i want?  Thanks!
Hi Nate,
Have a look at color2D.matplot, especially the last example.

Jim