ggplot combining two plots from different data.frames
RGgplot2R Problem Overview
I want to combine two ggplots, from two different data.frames, into one plot. Below you will find the code. I want to combine plot 1&2 or plots 3&4.
df1 <- data.frame(p=c(10,8,7,3,2,6,7,8),
v=c(100,300,150,400,450,250,150,400))
df2 <- data.frame(p=c(10,8,6,4), v=c(150,250,350,400))
plot1 <- qplot(df1$v, df1$p)
plot2 <- qplot(df2$v, df2$p, geom="step")
plot3 <- ggplot(df1, aes(v, p)) + geom_point()
plot4 <- ggplot(df2, aes(v, p)) + geom_step()
This must be very easy to do, but somehow I can't get it to work. Thanks for your time.
R Solutions
Solution 1 - R
As Baptiste said, you need to specify the data argument at the geom level. Either
#df1 is the default dataset for all geoms
(plot1 <- ggplot(df1, aes(v, p)) +
geom_point() +
geom_step(data = df2)
)
or
#No default; data explicitly specified for each geom
(plot2 <- ggplot(NULL, aes(v, p)) +
geom_point(data = df1) +
geom_step(data = df2)
)
Solution 2 - R
The only working solution for me, was to define the data object in the geom_line instead of the base object, ggplot.
Like this:
ggplot() +
geom_line(data=Data1, aes(x=A, y=B), color='green') +
geom_line(data=Data2, aes(x=C, y=D), color='red')
instead of
ggplot(data=Data1, aes(x=A, y=B), color='green') +
geom_line() +
geom_line(data=Data2, aes(x=C, y=D), color='red')
Solution 3 - R
You can take this trick to use only qplot. Use inner variable $mapping. You can even add colour= to your plots so this will be putted in mapping too, and then your plots combined with legend and colors automatically.
cpu_metric2 <- qplot(y=Y2,x=X1)
cpu_metric1 <- qplot(y=Y1,
x=X1,
xlab="Time", ylab="%")
combined_cpu_plot <- cpu_metric1 +
geom_line() +
geom_point(mapping=cpu_metric2$mapping)+
geom_line(mapping=cpu_metric2$mapping)