Finding mean of matrix excluding 0

I have a 4 1200x1200 matrixes which includes numerous 0 values, lets just call them 'a' 'b' 'c' and 'd'

How do i find the mean of each individual point in the matrix (that is a+b+c+d), while ignoring the 0 values?

Thank you for the help!

Answer 1

[Star Strider]

If I understand correctly what you want to do, this will work:

a = randi([0 5], 10);
b = randi([0 5], 10);
c = randi([0 5], 10);
d = randi([0 5], 10);

abcd = cat(3, a, b, c, d);                              % Concatenate Along 3rd Dimension
abcd(abcd == 0) = NaN;                                  % Set Zeros To ‘NaN’
mean_abcd = mean(abcd, 3, 'omitnan');                   % Use 'omitnan' Argument And Take ‘mean’ Across 3rd Dimension

Answer 2

[Image Analyst]

You mean the mean at each location, like (a+b+c+d)/(# non-zeros)? How about

counts = (a~=0) + (b~=0) + (c~=0) + (d~=0);
theMeans = (a+b+c+d) ./ counts;

theMeans is a 1200-by-1200 matrix where each value is the mean of up to 4 values. If all 4 values are 0 then the value there is a nan.

[goyanks1989]

Thank you for the answer. When I run my code I receive this error message

Error using  ./ 
Integers can only be combined with integers of the same class, or scalar doubles

is this because my matrix is a 1200x1200 uint16? (and i am not exactly sure what uint16 means)

[Image Analyst]

They are not all uint16 - some must be different. Cast all to double and then do it.