Replace NaN values with a formula

%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.

Answer 1

[Bruno Pop-Stefanov]

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

[Caleb]

Bruno,

Thank you so much for your help. It worked perfectly!

Caleb