ggplot + geom_point + legend based on both size and color

Question

Is there a way to display both size and color in the legend when using geom_point?

library(ggplot2)
cons2 <- data.frame(
  value_date  = as.Date(c('2013-04-30', '2013-04-30', '2013-06-13', '2013-06-13')),
  ticker = c('AAPL','FTW','AAPL','FTW'),
  discount = c(0.34,0.10,0.25,0.20),
  b = c(0.40,0.55,.60,0.90),
  yield = c(0.08,0.04, 0.06,0.03)
)

p <- ggplot(cons2)
p <- p + geom_point(aes(yield,b, size = discount, color=value_date))
p

This plot will only show size(discount) in the legend, but I would like to display both size(discount) and color(value_date).

score 3 · Accepted Answer · answered Jun 14 '13 at 18:16

3

ggplot2 doesn't know quite what to do with the Date class. Try:

color=factor(value_date)

instead.

answered Jun 14 '13 at 18:16

joran

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Thanks that fixed my problem. Is there a way to only show value_date in the legend and not discount? – Børge Klungerbo Jun 14 '13 at 18:25
@BørgeKlungerbo Yes, `p + guides(size = "none")`. – joran Jun 14 '13 at 18:27
Thanks alot for the prompt answer! – Børge Klungerbo Jun 14 '13 at 18:34

score 1 · Answer 2 · answered Jun 16 '13 at 12:38

1

For some reason ggplot2 isn't automatically figuring out that it needs the date frame. Try telling it explicitly:

ggplot(cons2) +
  geom_point(aes(yield, b, size = discount, color = value_date)) +
  scale_colour_gradient(trans = "date")

answered Jun 16 '13 at 12:38

hadley

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ggplot + geom_point + legend based on both size and color

2 Answers2