MATLAB: Replace NaN values with a formula

nan valuesreplace

%I am looking to replace NaN values in a given matrix using a formula.
%Suppose that row 1 of matrix A are totals (See column 3).
%Row 2-4 are subsectors that when summed equal the total.
A = [1100 1200 1125 1635 1850; 45 22 NaN 35 51; NaN NaN 510 600 782; 732 522 534 1000 NaN]
%Another matrix C corresponds to a particular row's average percentage of the total.
C =
    0.0281    0.4143    0.5633
%I want to replace each NaN value by multiplying the Total by the coresponding average for that row.
%ie. The NaN value that occurs at A(3,1) would be replaced by .4143*1100=414.3
%any help would be appreciated.

Best Answer

Hi Caleb,
You can use the function isnan to check if an element of A is not a number. In your case, I would go through every element of A, check if it is NaN and replace it with your formula using C. This can be done with a simple for loop as follows:
for row=2:size(A,1)
    for col=1:size(A,2)
        if isnan(A(row,col))
            A(row,col) = A(1,col) * C(row-1);
        end
    end
end
I hope that helps!
-Bruno
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