> I'd like to calculate the percent of values in part of the matrix -- i.e., from 401:440 and 1081:1360 -- where values are less than or equal to 5, exclusing NaN values.
A = randi(10,720,1440);
mu = mean(A(401:440,1081:1360)<=5,'all','omitnan')
> I'd like to first count the number of elements for this part of A (401:440,1081:1360) where values are less than 5, but omiting any NaN values.
As you can see above, this step isn't needed. But for completeness,
count = sum(A(401:440,1081:1360)<=5,'all','omitnan')
To verity the mean computed above,
totalNumberOfElements = numel(A(401:440,1081:1360))
myConfirmed = count/totalNumberOfElements
