I have a list of data frames like the following:
set.seed(123)
a<- data.frame(x=runif(10), y = runif(10), sample = seq(1,10))
b<- data.frame(x=runif(10), y = runif(10), sample = seq(1,10))
L<- list(a,b)
All data frames in the list have the same dimensions. I need to calculate
the sample means for x and y. The real data are lists of several thousand
quite large dataframes, so I need something that is pretty fast. Here is
what I have so far:
y<- rowMeans(sapply(L,'[[','y'))
x<- rowMeans(sapply(L,'[[','x'))
this works great, but I'm only able to get the sample means for one column
at a time. Is there a way to automate things a bit so that I can get the
sample means for several columns with one call?
Thanks for any suggestions,
Matthew
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