### 41.8 Matrix Operations

Function: int gsl_spmatrix_add (gsl_spmatrix * c, const gsl_spmatrix * a, const gsl_spmatrix * b)

  This function computes the sum c = a + b. The three matrices must have the same dimensions and be stored in a compressed format.

Function: int gsl_spmatrix_scale (gsl_spmatrix * m, const double x)

  This function scales all elements of the matrix m by the constant factor x. The result m(i,j) \leftarrow x m(i,j) is stored in m.