I have edited the CG algo to extract the trace by searching points. this would...

I have edited the CG algo to extract the trace by searching points. this would be faster and more stable if we just stored the trace. This is not memory efficent but that may not be such a consern. alternativly we could store off diagonals with the SRS but the diagonal directly, this would improve the algorithm and should be more sparce since we wouldnt need the store the coords for the diagonals, somthing we currently do.