Custom heat map in R

Question

I need to create my own heat map, as shown in the attached figure. It differs from a regular heat map in the sense that I want it to use two color gradients, one for positive values ​​and one for negative values.

As shown in the attached figure, I would like one color to reflect the intensity of values ​​that are positive (or ideally above a certain threshold) and another color to represent the intensity of negative values ​​(alternatively below the threshold).

A small background: I have a binary choice, one option should be preferable for a certain range of data, while the other is preferable to the rest of the data. I want to provide visual help that will show which option / choice is better for different data combinations, but I want the visual help to also provide the “gloss” scale that one option has over the other for this instance. Thus, the color will tell you which option to choose, and the color intensity - tell how much better this option compared to the other.

Answer 1

here is an example using ggplot2 :

 # sample data df <- data.frame(expand.grid(x = 1:4, y = 1:4), v = runif(16, -10, 10)) # plot ggplot(df, aes(x, y, fill = v, label = sprintf("%.1f", v))) + geom_tile() + geom_text() + scale_fill_gradient2(low = "blue", high = "red")