given an L*D*L' factorization of an n*n matrix A, return the updated
factorization L2*D2*L2' of A plus the following "top left" matrix:
[ b a' ] <-- b is a[0]
[ a 0 ] <-- a is a[1..n-1]
- L has size n*n, its leading dimension is nskip.
Given an L*D*L' factorization of an n*n matrix A, return the updated
factorization L2*D2*L2' of A plus the following "top left" matrix:
[ b a' ] <-- b is a[0]
[ a 0 ] <-- a is a[1..n-1]
- L has size n*n, its leading dimension is nskip.
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Plane2D
2d joint, constrains to z == 0
This code is part of the Plane2D ODE joint
by psero@gmx.de
Wed Apr 23 18:53:43 CEST 2003
given `L', a n*n lower triangular matrix with ones on the diagonal,
and `d', a n*1 vector of the reciprocal diagonal elements of an n*n matrix
D, solve L*D*L'*x=b where x,b are n*1.
Given `L', a n*n lower triangular matrix with ones on the diagonal,
and `d', a n*1 vector of the reciprocal diagonal elements of an n*n matrix
D, solve L*D*L'*x=b where x,b are n*1.