Transform back from colors to values
Transform back from colors to values
col2value(r, g, b, col_fun)
r | 
 red channel in   | 
g | 
 green channel in   | 
b | 
 blue channel in   | 
col_fun | 
 the color mapping function generated by   | 
colorRamp2 transforms values to colors and this function does the reversed job.
Note for some color spaces, it cannot transform back to the original value perfectly.
A vector of original numeric values.
Zuguang Gu <z.gu@dkfz.de>
x = seq(0, 1, length = 11)
col_fun = colorRamp2(c(0, 0.5, 1), c("blue", "white", "red"))
col = col_fun(x)
col2value(col, col_fun = col_fun)
col2value("red", col_fun = col_fun)
col_fun = colorRamp2(c(0, 0.5, 1), c("blue", "white", "red"), space = "sRGB")
col = col_fun(x)
col2value(col, col_fun = col_fun)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.