R: Density plot with colors by group?

Question

I have data from 2 populations. I\'d like to get the histogram and density plot of both on the same graphic. With one color for one population and another color for the other on

Answer 1

I suggest this ggplot2 solution:

ggplot(todo, aes(valores, color=grupo)) +
  geom_histogram(position="identity", binwidth=3, aes(y=..density.., fill=grupo),  alpha=0.5) +
  geom_density()

@skan: Your attempt was close but you plotted the frequencies instead of density values in the histogram.