Dividing two non-zero arrays gives me an array of zeros

Hi, I'm dividing two arrays of equal size by eachother. These arrays do have 0's in them but not all the values are zero.

When I Divide the two I get an array of equal size to them both but all elements in the array are zero.

Here is an example

if true
x = ones(100)
y = ones(100)
z = x./y
z
  % code
end

except when I return my 'z' I get an array of zeroes. Does anyone have any idea why this is and what a fix might be?

My x is a 100x100 double and my y is 100x100 double

Any help appreciated as always

[jgg]

Does that code in your example generate all zeroes for you? It doesn't on my system (Windows 10 x64, R2015a)?

[John Draper]

Yes, for me it does.

whos z is a 100x100 double in my code

Answer 1

[Walter Roberson]

Your actual arrays are one of the integer data classes, such as if you are trying to divide one uint8 image by another . You need to double() the arrays before doing the division.

[John Draper]

Here is a section of my code, does this look correct?

ii = double(b_c(:,:,1))
jj = double(b_c(:,:,2))
kk = double(b_c(:,:,3))
rMPCdouble = double(rMagPriCubed)
b_ci = ii./rMPCdouble;
b_cj = jj./rMPCdouble;
b_ck = kk./rMPCdouble;

[Walter Roberson]

Looks plausible.

new_b = b_c ./ double(rMagPriCubed(:,:,[1 1 1]));

and now you could select layers from new_b if you wanted.