Index exceed matrix dimensions.

I wrote the following codes, but after commanding it for a run, it is showing that index exceeds matrix dimension and error in testmisr(line 11) if od(a,b,c,d,e)==-9.999. the codes:

for i = 1:30;
filename_apr = ['/Users/Sudipta/Documents/misr daily data/mar00-feb01/061703666281887/MISR_AMI_CGAS_APR_',num2str(i),'_2000_F15_0031.hdf'];
od(i,:,:,:,:,:) = hdfread('F:\Modis_TERRA_daily\MISR_AM1_CGAS_APR_01_2000_F15_0031.hdf', '/AerosolParameterAverage/Data Fields/Optical depth average', 'Index', {[122  538  1  2  1],[1  1  1  1  1],[12  18    1    1    6]});
for a = 1:12;
  for f = 1:31
    for b = 1:18;
      for c = 1:1;
          for d = 1:1;
              for e = 1:6;
                  if od(f,a,b,c,d,e)== -9999;
                      od(f,a,b,c,d,e) = NaN;
                   else if od(f,a,b,c,d,e)==-9.999;
                        od(f,a,b,c,d,e) = NaN;
                  else
                      od(f,a,b,c,d,e)=od(f,a,b,c,d,e);
                  end
              end
          end
      end
  end
end
end

[Chandrasekhar]

index is trying to access the matrix element which doesnt exist. index > length(array/matrix)

Answer 1

[Patrik Ek]

You do not need make all these for loops for this. Instead of

for a = 1:12;
 for f = 1:31
  for b = 1:18;
    for c = 1:1;
        for d = 1:1;
            for e = 1:6;
                if od(f,a,b,c,d,e)== -9999;
                    od(f,a,b,c,d,e) = NaN;
                 else if od(f,a,b,c,d,e)==-9.999;
                      od(f,a,b,c,d,e) = NaN;
                else
                    od(f,a,b,c,d,e)=od(f,a,b,c,d,e);
                end
            end
        end
    end
 end
end

do something like,

od(od == -9999 | od==-9.999) = nan;

This will not only solve the index out of bounds problem, but speed up your code quite a lot as an extra bonus.

BR/Patrik

[Patrik Ek]

If you is still in to doing loops I would then suggest

od = od(:);
% do operations
od = reshape(od,len_a,len_b,...)

Since matlab works absolutely best for columns.