I wonder if there is a way to calculate the distance between a abline in a plot and a datapoint? For example, what is the distance between concentration == 40 with signal == 643 (element 5) and the abline?
concentration <- c(1,10,20,30,40,50)
signal <- c(4, 22, 44, 244, 643, 1102)
plot(concentration, signal)
res <- lm(signal ~ concentration)
abline(res)