docs: public static double[] timesMinus(final double[] v1, final double s1, final double[] v2) {
      assert v1.length == v2.length : ERR_VEC_DIMENSIONS;
      final double[] sub = new double[v1.length];
      for(int i = 0; i < v1.length; i++) {
        sub[i] = v1[i] * s1 - v2[i];
      }
      return sub;
    }