Question

I got a simple data.frame (AD0) with basic statistical values and the factor(group):

       mean         se        sd median group
value1 0.725 0.07149951 0.4522026      1     1
value2 0.650 0.07637626 0.4830459      1     2
value3 0.175 0.06084343 0.3848076      0     3
value4 0.375 0.07752171 0.4902903      0     4

I tried to make a simple barplot with:

p <- ggplot(AD0, aes(mean,group)) + geom_bar()

However, I get the message: “Error: No layers in plot”
It is such a simple thing and I can’t get my head around why its not working.

I would be really glad if somebody could help me

Answer 1

Since you have presummarised data, you need to specify stat = "identity" in geom_bar.

library(ggplot2)
ggplot(AD0, aes(group, mean)) + geom_bar(stat = "identity")

Furthermore, I suppose you want to use group for the x-axis and mean for the y-axis. I switched the order of both names.