docs: public static void rank1UpdateMultL(DMatrixRMaj A , double u[] ,
                                          double gamma ,
                                          int colA0,
                                          int w0 , int w1 )
      {
          for( int i = colA0; i < A.numRows; i++ ) {
              int startIndex = i*A.numCols+w0;
              double sum = 0;
              int rowIndex = startIndex;
              for( int j = w0; j < w1; j++ ) {
                  sum += A.data[rowIndex++]*u[j];
              }
              sum = -gamma*sum;
  
              rowIndex = startIndex;
              for( int j = w0; j < w1; j++ ) {
                  A.data[rowIndex++] += sum*u[j];
              }
          }
      }