Avoid NaNs in a sum of a for loop

Hi all! I have a problem.. here is my code..

for l=12:length(PM25)
    if isnan(PM25(l)) || (isnan(PM25(l-1))) && (isnan(PM25(l-2)))
        C(l)=NaN; 
    else
        C(l) = (PM25(l)*(w(l)^0)) + (PM25(l-1)*(w(l)^1)) + (PM25(l-2)*(w(l)^2)) + ... 
            (PM25(l-3)*(w(l)^3)) + (PM25(l-4)*(w(l)^4)) + (PM25(l-5)*(w(l)^5)) + ...
            (PM25(l-6)*(w(l)^6)) + (PM25(l-7)*(w(l)^7)) + (PM25(l-8)*(w(l)^8)) + ...
            (PM25(l-9)*(w(l)^9)) + (PM25(l-10)*(w(l)^10)) + (PM25(l-11)*(w(l)^11));
    end
end

Some of those multiplications results are NaN.. How can i avoid them?

Thank you!

Answer 1

[Ameer Hamza]

I suggest something like this

for l=12:length(PM25)
    C(l) = sum(PM25(l:-1:l-11).*w(l).^(0:11)); % no need to write each term manually
end
C(isnan(C)) = 0; % set nan values to zero.

[Thodoris Ptrks]

maybe I wasn't clear... some of them PM25(l-1)*(w(l)^1) give NaN so the whole sum is getting NaN.. i neen to avoid them so the sum has value.. thank you..

[Ameer Hamza]

What about setting the nan values 0 before the for loop so that they will have no effect on multiplication

PM25(isnan(PM25)) = 0;
w(isnan(w)) = 0;
for l=12:length(PM25)
    C(l) = sum(PM25(l:-1:l-11).*w(l).^(0:11)); % no need to write each term manually
end
C(isnan(C)) = 0; % set nan values to zero.

[Thodoris Ptrks]

it works! Thank you very much!

[Ameer Hamza]

Glad to be of help.