Attempted to access A(0,0); index must be a positive integer or logical.

when i run this code it tells me A(0,0); index must be a positive integer or logical.

clc; 
clear;
close all;  
A=xlsread('DEM_Topography.xlsx');
C=xlsread('pyramiddem2.xlsx');
B=C(1:13,1:13);
i=1;
j=1;
for i=1:33
  for j=1:75
      volA(i,j)=((A(i-1,j-1)+A(i,j-1)+A(i-1,j)+A(i,j))/4)*2500;
  end
end
for jj=1:5
  for ii=1:25
      for i=1:13
          for j=1:13
              vol(i,j)=B(i,j)-volA(i+ii,j+jj);
                  if vol(i,j) < 0;
                      vol(i,j)=0;
                  end      
          end
      end
      x(ii,jj)=sum(sum(vol));
  end
end
y=x/1000;
disp(y)

%Price of Volume of sand
for ij=1:5
  for iv=1:25
    if y(iv,ij) > 5000
      price_sand(iv,ij)=(100*(y(iv,ij)-5000));
    else
      price_sand(iv,ij)=(160*(5000-y(iv,ij)));
    end
    if price_sand(iv,ij) > 150000;
      price_sand(iv,ij) = 0;
    end
  end 
end
disp('Price of sand zeros indicate over $150,000')
disp(price_sand)

Answer 1

[dpb]

Ayup...

for i=1:33
  for j=1:75
      volA(i,j)=((A(i-1,j-1)+A(i,j-1)+A(i-1,j)+A(i,j))/4)*2500;

when, i,_j_==1, the i-1 and j-1 indices are zero, indeed. Zero is not a positive integer and Matlab arrays are 1-based.

Start the loop indices at 2 instead. Also the loop could be replaced with filter2