Indicates if a duplicated sparse matrix should have its numerical values copied over or just its nonzero structure.
MAT_DO_NOT_COPY_VALUES- Create a matrix using the same nonzero pattern as the original matrix, with zeros for the numerical values
MAT_COPY_VALUES- Create a matrix with the same nonzero pattern as the original matrix and with the same numerical values.
MAT_SHARE_NONZERO_PATTERN- Create a matrix that shares the nonzero structure with the previous matrix and does not copy it, using zeros for the numerical values. The parent and child matrices will share their index (i and j) arrays, and you cannot insert new nonzero entries into either matrix