Adding linear regression line to ggplot2 dotplot on R

Question

I want to add a linear regression line to a semi-log dotplot but I can't seem to get it to work.

mm= c(44.637, 41.252, 38.717, 36.176, 34.275, 32.366, 30.676, 29.407, 27.715, 26.866)

bp = c(100, 200, 300, 400, 500, 600, 700, 800, 900, 1000)

ladder = data.frame(mm, bp)

ggplot2.dotplot( data=ladder, xName= 'bp', yName= 'mm', mainTitle='Ladder') + scale_y_log10(breaks = trans_breaks('log10', function(x) 10^x), labels = trans_format('log10',math_format(10^.x)))

I've tried >geom_smooth, >geom_abline, and >stat_smooth. None of these work. Help would be very much appreciated.

navinkb navinkb · Accepted Answer · 2016-04-11T05:24:36

dotplot is not suitable for this data. I think you are looking for scatter plot.

This code worked for me.

ggplot(ladder, aes(bp, mm)) + geom_point() +  
scale_y_log10(breaks = trans_breaks('log10', function(x) 10^x), labels =  trans_format('log10',math_format(10^.x))) +
geom_smooth(method ="lm")

In smooth function, method = "lm" fits a linear regression line

Adding linear regression line to ggplot2 dotplot on R

1 Answers