Computing the average across columns, while discounting a specific column

What is the best way to compute the simple average across the columns of a matrix, when one of the columns must be completely discounted?

[madhan ravi]

Example?

Answer 1

[Stephen23]

Say you have a matrix M and you want to get the mean of each row, ignoring the third column:

N = 3; % column to ignore
mean(M(:,[1:N-1,N+1:end]),2)

Answer 2

[madhan ravi]

Not sure what you mean but a guess:

x=rand(4)
x(:,2)=[] %removes second column
mean(x,1)

[Image Analyst]

This changes x, while Stephen's code doesn't change the matrix. Your code also gets the mean along rows (down rows in each column) instead of "across columns", though I'll admit it might be a bit ambiguous what "across columns" actually means.

[madhan ravi]

ok @sir Image Analyst I was thinking to remove my answer anyway thank you for pointing the error :)