Skip to main content
16 events
when toggle format what by license comment
Jul 27, 2015 at 11:00 history edited J. M.'s missing motivation CC BY-SA 3.0
added 7 characters in body
Jul 26, 2015 at 10:38 answer added J. M.'s missing motivation timeline score: 12
Jun 6, 2015 at 10:52 answer added Alexey Popkov timeline score: 7
Jun 6, 2015 at 10:43 history edited J. M.'s missing motivation
edited tags
Oct 27, 2013 at 12:13 answer added Tobi timeline score: 15
Sep 30, 2013 at 17:08 answer added Andy Ross timeline score: 31
Sep 29, 2013 at 18:30 history edited jojosthegreat CC BY-SA 3.0
edited title
Sep 29, 2013 at 17:51 comment added jojosthegreat Dear Belissarius thank you for your response. All these posts state that we must duplicate the external knots d times, where d is the degree of the spline. I know that fact, but why my second problem persists? Anyway, this correction seems to cure many instabilities, but not all: a = LinearSolve[ Transpose[X].X + lambda*Transpose[Dsq]. Dsq, Transpose[X].data, Method -> "Krylov"] // N;
S Sep 29, 2013 at 17:37 history suggested Sektor CC BY-SA 3.0
Reformatted
Sep 29, 2013 at 17:30 review Suggested edits
S Sep 29, 2013 at 17:37
Sep 29, 2013 at 17:21 comment added jojosthegreat Actually the problem persists: LinearSolve::luc: "Result for ... of badly conditioned matrix may contain significant numerical errors.
Sep 29, 2013 at 17:09 comment added jojosthegreat Thank you very much ssch. The algorithm is more stable now. But I am still in doubt for the duplication of the first and the last point as knots. Anyway, you helped me a lot.
Sep 29, 2013 at 17:03 review First posts
Sep 29, 2013 at 17:30
Sep 29, 2013 at 17:00 comment added Dr. belisarius have you seen this? mathematica.stackexchange.com/…
Sep 29, 2013 at 16:47 comment added ssch Always avoid calling Inverse when you can use LinearSolve. Solving a linear system is much faster and stabler than calculating an inverse.
Sep 29, 2013 at 16:43 history asked jojosthegreat CC BY-SA 3.0