docs: public static double elementMaxAbs( DMatrixSparseCSC A ) {
          if( A.nz_length == 0)
              return 0;
  
          double max = A.isFull() ? Math.abs(A.nz_values[0]) : 0;
          for(int i = 0; i < A.nz_length; i++ ) {
              double val = Math.abs(A.nz_values[i]);
              if( val > max ) {
                  max = val;
              }
          }
  
          return max;
      }