How to make a log operation for a matrix excluding the '-inf' values?

Hello everyone!

I want to do it a log operation in a matrix and I developed the following loop:

   for ii = 1: size (IDHMA,1)
    for kk = size (IDHMA,2)
       IDHMAlog (ii,kk) = log(IDHMA(ii,kk))
       if IDHMA(ii,kk) == 0
           IDHMAlog(ii,kk) = NaN %exclude the"-Inf" values
       else 
           IDHMAlog (ii,kk) = log(IDHMA(ii,kk))
       end
    end
   end

But the result is giving me a matrix in the same dimension but with zeros and the the log operation result only in the last column. Does anyone know how to fix it ?

Thanks

Answer 1

[Tommy]

k should span from 1 to size(IDHMA,2), similar to ii:

for ii = 1: size (IDHMA,1)
for kk = 1 : size (IDHMA,2)
   IDHMAlog (ii,kk) = log(IDHMA(ii,kk))
   if IDHMA(ii,kk) == 0
       IDHMAlog(ii,kk) = NaN %exclude the"-Inf" values
   else 
       IDHMAlog (ii,kk) = log(IDHMA(ii,kk))
   end
end
end

I believe you could avoid the loops if you'd like:

IDHMAlog = log(IDHMA);
IDHMAlog(IDHMA==0) = NaN;

[Julia Moore]

Yeaah! That worked. Thank you so much!!