Damping matrix evalA unequal to damping matrix evalU + evalL

[Jannertje]

The setting is as follows: we have the orthonormal discontinuous piecewise linear wavelet basis from figure 2. We want to apply the damping matrix $C_{\mu,\lambda} := \int_0^1 \phi_{\mu} [\partial_t \phi_{\lambda}] d t$, as it is a more interesting operator than the mass matrix (which is the identity by definition of this basis).

One can verify numerically (see Mathematica/evalA.nb in the git) that the singlescale damping matrix at level 0 equals $C^{ss}_0 = \begin{bmatrix} 0 & 2 \sqrt{3} \\ 0 & 0 \end{bmatrix}$.

Moreover, one can verify using Mathematica (see Mathematica/evalA.nb in the git) that for $\ell=1$, the multiscale damping matrix satisfies $C^{ms}_1 = \begin{bmatrix} 0 & 2 \sqrt{3} & -6 & 0 \\ 0 & 0 & 0 & 6 \\ 0 & 0 & 0 & 2 \sqrt{3} \\0 & 0 & 0 & 0 \end{bmatrix}$.

If we compute $C^{ms}_1$ as $U_1 + L_1$ (Applicator::apply_upp + Applicator::apply_low), we retrieve this matrix. However, if we compute it as $C^{ms}_1$ directly (Applicator::apply), we get the incorrect matrix $\begin{bmatrix} 0 & 2 * 2 \sqrt{3} & -6 & 0 \\ 0 & 0 & 0 & 6 \\ 0 & 0 & 0 & 2 \sqrt{3} \\0 & 0 & 0 & 0 \end{bmatrix}$.

For higher levels, $U_\ell + L_\ell$ retrieves the correct matrix but $C^{ms}_\ell$ directly seems to overshoot the nonzero elements by a factor $\ell - |\lambda|$ or something, very peculiar. Run python/applicator_test.py:test_orthonormal_multiscale_damping_equivalent to see.

[Jannertje]

Fixed in 77a900c. Sigh stupid mistake