Kjetil Kjernsmo
2000-Jul-27 18:01 UTC
[R] Interpolation using a piecewise linear function in higher dimensions
Dear all, I am just wondering if anybody has implemented a function that can give a piecewise linear interpolation in more than 2 dimensions? I have looked at the akima package, but I would rather like a piecewise linear interpolation rather than a spline and while it did the job quite satisfactory for 2 dimensions, I need to interpolate in at least three dimensions. If anybody has implemented something like that, and would like to share the code, I would be very happy. Or if someone knows a library that can do it that wouldn't be too hard to port (I have searched in netlib, found one function that was a bit hard to understand and seemed like overkill, and looked in the GSL documentation without finding anything appropriate). Best, Kjetil -- Kjetil Kjernsmo Graduate astronomy-student Problems worthy of attack University of Oslo, Norway Prove their worth by hitting back E-mail: kjetikj at astro.uio.no - Piet Hein Homepage <URL:http://www.astro.uio.no/~kjetikj/> Webmaster at skepsis.no -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Prof Brian D Ripley
2000-Jul-27 20:29 UTC
[R] Interpolation using a piecewise linear function in higher dimensions
On Thu, 27 Jul 2000, Kjetil Kjernsmo wrote:> Dear all, > > I am just wondering if anybody has implemented a function that can give a > piecewise linear interpolation in more than 2 dimensions? > I have looked at the akima package, but I would rather like a piecewise > linear interpolation rather than a spline and while it did the job quitepiecewise linear interpolation is a spline of order one.> satisfactory for 2 dimensions, I need to interpolate in at least three > dimensions. If anybody has implemented something like that, and would like > to share the code, I would be very happy. Or if someone knows a library > that can do it that wouldn't be too hard to port (I have searched in > netlib, found one function that was a bit hard to understand and seemed > like overkill, and looked in the GSL documentation without finding > anything appropriate).For 3D this is widely used in mechanical CAD packages and `finite element' code. In kD, k > 1, one issue is what the pieces should be, and even a regular grid poses problems of non-unique solutions. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._