R: Calculate RMS for subset of a group

Question

I would like to calculate the RMS of A and B from the following dataset in R:

Var Diff
A  -360
A   361
A  -362
B  -500
B  -647
B   700

I have found a great post about calculating the mean of a subset using the aggregate function here: R: Calculate means for subset of a group.

Is there a way to use the aggregate function to calculate the RMS of a subset? If not, then any other approach would be appreciated. Thanks.

Do you want something like this? `sqrt(mean(abs(Diff)) ** 2)`? That is what do you mean by RMS? What is your expected output? — NelsonGon, Oct 08 '19 at 07:31
Hello, I meant sqrt(mean((Diff)^2)). My expected output would RMS_A=361.001 and RMS_B=621.452. — Tanjil, Oct 08 '19 at 07:58
Try: `aggregate(Diff ~ Var, data=dataset, function(Diff) {sqrt(mean((Diff)^2))})` — GKi, Oct 08 '19 at 08:00

score 0 · Accepted Answer · answered Nov 11 '20 at 08:30

0

The answer has been provided by GKi:

aggregate(Diff ~ Var, data=dataset, function(Diff) {sqrt(mean((Diff)^2))})

answered Nov 11 '20 at 08:30

Tanjil

1 Answers1