Computation failed for stat_summary, 'what' must be a character string or a function
Solution 1
The reason is that you have a variable called mean
in your workspace. So when you call stat_summary
…
stat_summary(aes(group = 1), geom = "line", fun.y = mean, size = 1, color = "black")
… R thinks that you’re referring to that variable, rather than the mean
function from the {base} package.
R is usually able to disambiguate between functions and other variables, even if they have the same name. However, in this case the disambiguation isn’t working because you’re not calling mean
directly but passing it as an argument. The solution is to manually disambiguate the function from the variable by doing either of these things:
- In the call to
stat_summary
, use the fully qualified namebase::mean
, rather than baremean
. - In the call to
stat_summary
, usematch.fun(mean)
instead of baremean
: this will tell R that you want to use a function. - Remove or rename the variable.
Solution 2
Similar problem for geom_smooth(method=lm, se=FALSE, fullrange=TRUE)
, I got exactly the same error message. Because I have lm in my global environment.
Just fixed the problem by changing lm
to "lm"
:
geom_smooth(method="lm", se=FALSE, fullrange=TRUE)
Solution 3
I got the same error when trying to plot summary stats for categories for a given continuous variable. The problem for mine was:
ggplot(data = diamonds) +
geom_pointrange(mapping = aes(x = cut, y = depth),
stat = "summary",
fun.ymax = max,
fun.ymin = min,
fun.y = median)
Functions are not called here as objects. After trying string form this worked for me:
ggplot(data = diamonds) +
geom_pointrange(mapping = aes(x = cut, y = depth),
stat = "summary",
fun.ymax = "max",
fun.ymin = "min",
fun.y = "median")
Admin
Updated on July 21, 2022Comments
-
Admin over 1 year
I am trying to following the script/example on
ChickWeight
plotting raw data in "Independent Group T intervals test", but keeps running into the following error forstat_summary
functionCode to reproduce here:
library(datasets) data(ChickWeight) library(ggplot2) g <- ggplot(ChickWeight, aes(x = Time, y = weight, colour = Diet, group = Chick)) g <- g + geom_line() g <- g + stat_summary(aes(group = 1), geom = "line", fun.y = mean, size = 1, color = "black") g <- g + facet_grid(. ~ Diet)
Error message:
"Computation failed instat_summary()
:
'what' must be a character string or a function"The error message is not very intuitive, I do not even see "what" as a param in the documentation of
stat_summary
, I did some research and check for others' answers but so far no concrete answer or solution to this problem. -
Salix over 4 yearskonrad answer's is more precise but this trick works just as well.