Average of a column without including a certain number

Is there a function for this or do I have to work with loops?

I have to calculate the average of a column without counting a specific number.

x = mean (A, 1)

Just ignoring a certain number. As with the function mean (nonzeros (x)), where you ignore the 0s.

Answer 1

[the cyclist]

There is no specific function for this, but it is easy to do without a loop:

A = [6; 3; 6; 4];
N = 6;
mean_A_without_N = mean(A(A~=N),1)

This uses logical indexing to identify the elements to be averaged.

[madhan ravi]

This forces the matrix into a column vector.

[Ferhat Sever]

thank you it worked :)

[Image Analyst]

It creates a temporary column vector when it does this A(A~=N). But the original A is never changed at all. The 1 in mean in not needed since it's a vector (regardless of what direction):

A = [6; 3; 6; 4];
N = 6;
mean_A_without_N = mean(A(A~=N))

It also (reasonably) assumes that you already have the column vector as A. If you don't, and you need to extract it from a 2-D matrix, you can do something like this to extract the 3rd column:

A = M(:, 3); % Extract third column (for example) from matrix M into a column vector.

Answer 2

[madhan ravi]

certain_number = 5; % example
A(A == certain_number) = NaN; % use A(ismember(A, certain_numbers)) = nan  if certain_numbers is more than one 
M = mean(A,'omitnan')
% or
M = nanmean(A)

[Steven Lord]

If you wanted to do this without modifying your original array you could use standardizeMissing.

A = [6 5 4; 3 6 2; 6 1 1]
mean(standardizeMissing(A, 6), 'omitnan') % [3, (5+1)/2, (4+2+1)/3]

[madhan ravi]

Thanks Steven.

[Ferhat Sever]

thank you a lot it worked :)