How to add legends in ggplot2?

Question

Probably very basic question about the legends in ggplot2 (sorry i am basic user user of R), I use this:

p<-ggplot(bAfr_topS1, aes(MAF, V3))+ geom_point()
p <- p+  geom_point(data=bEur_topS1,aes(MAF,V3),colour="red")+
  geom_point(data = bSas_topS1, aes(MAF, V3), colour="blue")

print(p)

but can't see the legends in output plot, any suggestion please? what should i add in?

You're using `ggplot2` the *wrong* (not optimal) way. Please check online tutorials (you need to bind your data and set color in `aes`). — pogibas, Jul 10 '18 at 09:52
Please share a reproducible example. Or use dput, so that others can understand your data and problem. — rar, Jul 10 '18 at 09:56

Maurits Evers · Answer 1 · 2018-07-10T10:43:13.087

0

It's difficult to give specific help without any data, but to illustrate the point @PoGibas is making and to get you started, try the following

library(tidyverse)
bind_rows(list(AF = bAfr_topS1, EU = bEur_topS1, PK = bSas_topS1), .id = "src") %>%
    ggplot(aes(MAF, V3, colour = as.factor(src))) +
    geom_point()

This assumes that bAfr_topS1, bEur_topS1, bSas_topS1 all have the same column structure.

edited Jul 10 '18 at 10:43

answered Jul 10 '18 at 09:58

Maurits Evers

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You should load `dplyr` or add `dplyr::\`%>%\`` – pogibas Jul 10 '18 at 10:10
1

Aaah very true @PoGibas; thanks:-) – Maurits Evers Jul 10 '18 at 10:14
Almost sorted! legends are 1 2 & 3, can i change 1 as AF, 2 as EU and 3 as PK? – bha Jul 10 '18 at 10:22
@bha made an edit. Please try again. – Maurits Evers Jul 10 '18 at 10:44
Sorted! many thanks – bha Jul 10 '18 at 10:55
Great and you’re very welcome @bha – Maurits Evers Jul 10 '18 at 11:03
PS Please consider closing the question by setting the green check mark next to the answer. This will help future SO users and tidy up SO questions/answers. – Maurits Evers Jul 12 '18 at 00:38

How to add legends in ggplot2?

1 Answers1