matlab: sparse matrix decomposition -

I am an initial matlab. I have a sample code, I have to understand what is happening with the piece of code snippet .

Sample.M

  n = 60;% Number of lengths divided by 84 =% N = 2 * I * n + m + n; A = spalloc (n, n, 4 * n); // A is a matrix for Jammu = 1: m if (masjet (j)> = 0) i = 1: n; A ((n + 1) * (J-1) + 1-1 + 1 +) + N + (n + 1) * (J -1) + I + 1) = Nuf (:, J). * KFN (:, j) * as * .ac./ ((1 + BI (, J) / 5) * (2 * d)) + N * mosset (j) * cfn (:, j) / L; One ((n + 1) * (J-1) + i-1 + 1-1) * N + (n + 1) * (J-1) + I + 1) = Nuf. (*, J) * KFN (:, J) * as * AC ./ ((1 + B (:, J) / 5) * (2 * Dhanbad)) - n * massdot (j) * CFN ( :, J) / L; A (((n + 1) * m + n * j + i-1) * N + (n + 1) * (J-1) + I + 1) = - Nuf. (:, J) * KFN (:, J) * as * AC ./ ((1 + B (:, J) / 5) * (2 * Dhanbad)); One ((n + 1) * m + n * (J-1) + i-1) * N + (n + 1) * (J-1) + I + 1) = - Nuf (:, J) . * KFN (:, J) * as * AC ./ ((1 + B (:, J) / 5) * (2 * Dhanbad)); B = stomach (FF ((n + 1) * (J-1) + I 1,1 +):, j) * massdot (j) ^ 3 / (2 * pf ^ 2 * ac ^ 2 * Dhanbad )); % Sticky extravagance I = 0; A ((n + 1) * (J-1) + i + 1, (n + 1) * (J -1) + I + 1) = 1; B ((n + 1) * (J -1) + I + 1,1) = th; ... x = a \ b; For Jammu = 1: i = 0: n; Tf (:, j) = full (x ((n + 1) * (j -1) + i + 1)); ...   
 Just tell me, what's going on with 9, 10, 11 and 9 lines? 12. Particularly expression is  =  on the left which is inside  () .  
 Edit:  
 Trying to find the updated code  Tf  matrix I can not share the entire code because it is my secret code of code is.   
 
 
 Actually, you set the value of  n   A  A  is a vector for some elements of the index (the long count between the brackets), because in the calculation you use the  i , which All elements of 1 to n have a vector.  
 Without some background information, it is difficult to say more about what the code should do.