DAY 23 OF 100] FRIDAY ,23 JAN 2015

1.Linear Algebra

cholesky fact with SPD -

     modified code to avoid transposing the column a21 to calculate rank1 update

Back sunbstitution implemented. No transposing of the LTM needed to do LLt = A

The algo now uses l21(which would be aa12t in the transpose) instead of  transposing L to get Lt .

All 3 routines are now tested

cholesky = takes in A which is an  SPD and converts it into an LTM with some old elements(of A) in upper triang part

solve_lzb = takes in the LTM (actually updated A )produced by cholesky , and a vector b.Updates b with the elements of z

solve_uxb = takes in the  LTM produced by cholesky, and the updated b (which now is actually z)

Originally,the L has to be transposed to get Lt and then solve Lt*x = b. Here we work with the required elements in LTM and ignore the old elements from A.The vector b is updated to contain elements of x.

This exercise helped to think about traversal thru matrix.. 

satisfying day :)