MATLAB: Need Matrix operation HELP

matricesmatrixmatrix arraymatrix manipulation

If I have:
T(:,:,1) =
     1     2     3
     4     5     6
     7     8     9
T(:,:,2) =
     1     4     7
     2     5     8
     3     6     9
I want to convert each matrix to be vector contains [(the sum of 1st row) (the sum of 2nd row) (the sum of 3rd row)] for example: Convert T(;,:,1) to be [6 15 24] where: 6 = 1+2+3 , 15 = 4+5+6 , 24 = 7+8+9 The same, Convert T(:,:,2) to be [12 15 18] where: 12 = 1+4+7 , 15 = 2+5+8 , 18 = 3+6+9 .. What's the function that can do it?

Best Answer

Use the sum function, specifying to sum acroww rows (dimension 2).
Example —
T1 = [1     2     3
      4     5     6
      7     8     9];
T2 = [1     4     7
      2     5     8
      3     6     9];
T = cat(3,T1,T2);
T_row_sum = sum(T,2)
T_row_sum(:,:,1) =
       6
      15
      24
T_row_sum(:,:,2) =
      12
      15
      18
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