CODEWITHSUNDEEP
rggplot2histogramlegend
Anna Maria Hupa
Anna Maria Hupa

Reputation: 11

How to add a legend to the multiple histograms with ggplot?

I am trying to add a legend to the graph but it doesn't work. Do you have any ideas ?

Here is my code :

  ggplot(data =stats_201507_AF ) +
  geom_histogram(aes(gross_ind),fill="dodgerblue3", show.legend =T,bins=25)+
  geom_histogram(aes(net_ind),fill="springgreen4",show.legend = T,bins=25) +
  geom_histogram(aes(tax_ind),fill="gold2",show.legend = T, bins=25) +
  xlab("Indices")+
  scale_colour_manual(values=c("dodgerblue3","springgreen4","gold2"))

I wanted a description for every histogram with a corresponding colour.

Thanks a lot in advance

Upvotes: 1

Views: 2875

Answers (1)

Roland
Roland

Reputation: 132989

If you don't want to reshape your data, just do this:

ggplot(iris) +
  geom_histogram(aes(x = Sepal.Length, fill = "Sepal.Length"), 
                 position = "identity", alpha = 0.5) +
  geom_histogram(aes(x = Sepal.Width, fill = "Sepal.Width"), 
                 position = "identity", alpha = 0.5) +
  scale_fill_manual(values = c(Sepal.Length = "blue",
                               Sepal.Width = "red"))

The key is that you need to map something to fill inside aes. Of course, reshaping your data to long format (and actually having a column to map to fill as a result) is usually preferable.

Upvotes: 3

Related Questions