display a matrix, including the values, as a heatmap

Question

What I\'d like to do is take this matrix:

> partb
                0.5  1.5   1a   1b   -2   -3
A1FCLYRBAB430F 0.26 0.00 0.74 0.00 0.00 0.00
A1SO604B523Q6         


        

Answer 1

Following lcgong (unfortunately I can post a direct comment) the pure transposition led to problems with the color representation. Accordingly, I rotated the matrix again and it worked. You can find the function as follows. Please make sure that the selected heatmap color scale works with n between 3 and 11. If desired, you can simply select another one here.

heatmap <- function(data, rowN, colN, xTitle = "", yTitle = "", numColors)
{
    # transpose and rotate matrix clockswise 90 degrees 
    dataAdjusted <- t(apply(data,2,rev))

    image(1:ncol(data), 1:nrow(data), xlab = xTitle, ylab = yTitle, dataAdjusted, col = rev(brewer.pal(numColors,"RdYlBu")), axes = FALSE)
    axis(1, 1:ncol(data), colN)
    axis(2, 1:nrow(data), rowN)

    for (x in 1:ncol(data))
        for (y in 1:nrow(data))
            # add text values into matrix based on transposed/rotated indices + round values to two digits
            text(x, y, round(dataAdjusted[x,y],2))
}

# required lib
library(RColorBrewer)

# Make a 8x8 matrix
m = matrix(rnorm(64), nrow=8)

# row names
rowN <- c("row 01", "row 02", "row 03", "row 04", "row 05", "row 06", "row 07", "row 08");
# column names
colN <- c("col 01", "col 02", "col 03", "col 04", "col 05", "col 06", "col 07", "col 08");

# without axis titles    
heatmap(m, rowN, colN, numColors = 10)

# alternatively with titles
heatmap(m, rowN, colN, xTitle = "xTest", yTitle = "yTest", numColors = 10)

Answer 2

levelplot() from the lattice package will give you a color legend. Not exactly what you want but something to think about.

Answer 3

For example:

m <- matrix(1:30, ncol=6)
colnames(m) <- paste("C", 1:6, sep="")
rownames(m) <- paste("R", 1:5, sep="")
m

image(1:ncol(m), 1:nrow(m), t(m), col = terrain.colors(60), axes = FALSE)
axis(1, 1:ncol(m), colnames(m))
axis(2, 1:nrow(m), rownames(m))
for (x in 1:ncol(m))
  for (y in 1:nrow(m))
    text(x, y, m[y,x])

Answer 4

There is another simpler way to make heatmaps with values. You can use pheatmap to do this.

dat <- matrix(rnorm(100, 3, 1), ncol=10)
names(dat) <- paste("X", 1:10)
install.packages('pheatmap') # if not installed already
library(pheatmap)
pheatmap(dat, display_numbers = T)

This will give you a plot like this

Answer 5

Try heatmap.2 from the gplots package. The cellnote and notecol parameters control the text placed in cells. You'll probably want dendrogram = "none" as well.

Answer 6

You can use image and text. I personally like image.plot from the fields package, because it adds a legend on the side, but you can use it with image too.

So for instance

require(fields)
# Make a 10x10 matrix
m = matrix(rnorm(100), nrow=10)
image.plot(m)
for (x in 1:10)
    for (y in 1:10)
        text((x-1)/9, (y-1)/9, sprintf("%0.2f", m[x,y]))