How to add legend to scatter plot in ggplot? - r

Question

I have assigned a shape and color to each point, and I want to draw the legend according to the group data, but I can't add the legend..
library(datasets)
library(tidyverse)
library(reshape2)
name <- c("S1","S1","S1","S2","S2","S3","S3","S3","S4","S4","S5")
x <- c(1,5,9,8,5,6,7,4,3,6,4)
y <- c(3,8,9,5,7,5,3,8,9,3,4)
Shape <- c(21,21,21,22,22,23,23,23,24,24,25)
Color <- c("red","red","red","blue","blue","green","green","green","purple","purple","black")
df <- data.frame(x,y,name,Shape,Color)
graph1 <- ggplot(df,aes(x,y,fill = Color, shape = Shape))+
geom_point(size = 4)+
scale_shape_identity()+
scale_fill_identity()
graph1
the x and y is the main data. The name is the group. The Shape and Color is the shape and color I assigned for all those point. How to draw a legend according to the group?

Answer 1

I think you are looking for:
ggplot(df, aes(x = x ,y = y, fill = name, shape = name)) +
geom_point(size = 4) +
scale_fill_manual(values = unique(df$Color)) +
scale_shape_manual(values = unique(df$Shape))

Answer 2

You were missing aes parameter color :-)
library(datasets)
library(tidyverse)
library(reshape2)
name <- c('S1', 'S1', 'S1', 'S2', 'S2', 'S3', 'S3', 'S3', 'S4', 'S4', 'S5')
x <- c(1, 5, 9, 8, 5, 6, 7, 4, 3, 6, 4)
y <- c(3, 8, 9, 5, 7, 5, 3, 8, 9, 3, 4)
Shape <- c(21, 21, 21, 22, 22, 23, 23, 23, 24, 24, 25)
Color <- c('red', 'red', 'red', 'blue', 'blue', 'green', 'green', 'green', 'purple', 'purple', 'black')
df <- data.frame(x, y, name, Shape, Color)
graph1 <- ggplot(df, aes(x, y, fill = Color, color = name, shape = Shape)) +
geom_point(size = 4) +
scale_shape_identity() +
scale_fill_identity()
graph1
You will note that using the group (name) as the basis for the legend makes this plot confusing, but in any case, you can add the color param to ensure that your legend is rendered.
if you use Color as the value for the color parameter you get the following: