From 793c01c9bd61a5b461b44fc7ede04cc1dd90a4ec Mon Sep 17 00:00:00 2001 From: Elizabeth Hunt Date: Mon, 27 Nov 2023 14:06:16 -0700 Subject: add shifted eigenvalue procedure and unit test --- homeworks/hw-7.org | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'homeworks') diff --git a/homeworks/hw-7.org b/homeworks/hw-7.org index dbdf6bb..ec8c23d 100644 --- a/homeworks/hw-7.org +++ b/homeworks/hw-7.org @@ -21,7 +21,23 @@ finds the least dominant eigenvalue on the matrix: 0 & 2 & 6 \end{bmatrix} -which has eigenvalues: $5 + \sqrt{17}, 2, 5 - \sqrt{17}$ and should produce $\sqrt{17}$. +which has eigenvalues: $5 + \sqrt{17}, 2, 5 - \sqrt{17}$ and should thus produce $5 - \sqrt{17}$. See also the entry ~Eigen-Adjacent -> least_dominant_eigenvalue~ in the LIZFCM API documentation. +* Question Four +See ~UTEST(eigen, shifted_eigenvalue)~ in ~test/eigen.t.c~ which +finds the least dominant eigenvalue on the matrix: + +\begin{bmatrix} +2 & 2 & 4 \\ +1 & 4 & 7 \\ +0 & 2 & 6 +\end{bmatrix} + +which has eigenvalues: $5 + \sqrt{17}, 2, 5 - \sqrt{17}$ and should thus produce $2.0$. + +With the initial guess: $[0.5, 1.0, 0.75]$. + +See also the entry ~Eigen-Adjacent -> shift_inverse_power_eigenvalue~ in the LIZFCM API +documentation. -- cgit v1.2.3-70-g09d2