问题
Is it possible to generate a heatmap taking into consideration both the color and the transparency, with these two parameters given from two different matrices (matrix 1 defines color, matrix 2 defines alpha)?
A little more information on what I'm after:
I have successfully used R and the heatmap.2 function in the gplots package to generate heatmaps - in this case to visualize miRNA interactions. Here, what I want to show is the probability of a particular nucleotide along the typical 20-24 nucleotides of the miRNA in being engaged in target pairing. My heatmap matrix consists of miRNAs (rows) and positions 1-24 (columns) with numeric paring probability in each cell. An example would be changing the alpha parameter of the color determined by the matrix values, such that white=no pairing and dark red=high pairing.
The heatmap.2 function works great for a single such plot, but I would now like to take in overlap information from two different species. Thus, I would need my heatmap to basically consider two matrices:
1) A matrix with the degree of species overlap, e.g. ranging from red-purple-blue for species1-only to species1+2 to species2-only.
2) A matrix with the average degree of pairing, e.g. visualized by the alpha parameter going from a weak-to-strong average pairing (whatever the color) at a given position in matrix 1.
I have tried to use the principles from this post:
Place 1 heatmap on another with transparency in R
But haven't been able to apply its suggestions to my own question.
Thanks in advance!
来源：https://stackoverflow.com/questions/29774618/making-a-heatmap-in-r-varying-both-color-and-transparency