Victor Liu
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 Dec 10 awarded Notable Question Aug 19 comment Decomposition of a degenerate conic @Pierluigi: How does one perform this decomposition algorithmically using computer routines? In your other post the lines $l$ and $m$ very much seem to be obtained "by inspection", but how do you do that rigorously? Jul 28 awarded Yearling Jul 2 reviewed Reject Polar Equation area Jul 2 answered A closed form for the coefficients of Chebyshev polynomials Jul 2 comment A closed form for the coefficients of Chebyshev polynomials The Wikipedia page gives some forms, but probably needs a lot of manipulation for what you want. May I ask why you want the monomial coefficients? Jul 1 answered Uniform Sampling on Intersection of Simplices Jul 1 comment Orthonormal basis for the null space of almost-Householder matrix This is not a Householder matrix. A Householder matrix is nonsingular. Jun 30 comment Uniform Sampling on Intersection of Simplices I assume you are performing rejection sampling on a transformed space rather than on a bounding box in the actual coordinate space of $x$? You should calculate the maximum volume inscribed ellipsoid and reparameterize in the bounding box of the rotated space (determined by the axes of the ellipsoid). These parameterizations can all be solved with convex programming so they should not be too computationally expensive. Jun 30 answered Why the Householder matrix is orthogonal? Jun 30 comment Eigenvalues of an upper Hessenberg matrix Check out this paper. Jun 30 comment Eigenvalues of an upper Hessenberg matrix Check out the MAGMA project that aims to implement linear algebra on the GPU. Edit: MAGMA doesn't support non-symmetric problems. Let me look up this other thing... Jun 30 comment Eigenvalues of an upper Hessenberg matrix And I'm sure the Matlab algorithm will take advantage of the fact that it is already upper Hessenberg, since I know that the Lapack code does it. Jun 30 answered Eigenvalues of an upper Hessenberg matrix Jun 30 comment Why does this hyperboloid change into a surface? The correct surface is two parallel planes. I don't know why in one case it would plot only one plane; that may be an artifact of the software you are using. Jun 30 answered Eigenvalue Deflation (Wielandt or Hotelling) Jun 30 comment Why does this hyperboloid change into a surface? Your code for the first expression has a typo; the x*y term appears twice. Jun 29 answered Delaunay Triangulation on Convex Polytopes — Uniform Sampling Jun 27 awarded Tenacious Jun 27 comment Numerically find a potential field from gradient Are your points on a grid or are they free-form?