MATLAB: I have a matrix which is 1000 columns and 3621 rows, how to take the mean of each row

Question

Basically I want to turn my matrix from dimensions 3621×1000 into 3621×1 by taking the means of each row.

Thank you for your help.

Answer 1

In general, if you have a matrix A and want to take the mean across a certain dimension, dim, you should use mean(A,dim).

dim = 1 gives the mean for each column, dim = 2 gives the mean for each row, and so on.

Here's an example for your case:

M = rand(3621,1000);
size(M)
ans =
         3621        1000
meanOfEachRow = mean(M,2)
size(meanOfEachRow)
ans =
         3621           1