Clement LAUZIN <lauzin <at> hotmail.com> writes: > Hello, > > Hello, > > I have a x,y,z file.Z is not corresponding to a simple analytical function > of x and y (see below). I am trying to find the minimum location of this > surface and the z value corresponding to this location by a spline > interpolation or from a polynomial fit. I tried with the akima package but > as the location of the point I am looking for (the minimum) is outside of > the convex hull it's not giving any answer. > If someone has any idea or any suggestion? > > Thank you in advance Pierre
According to a 2-dimensional barycentric Lagrange interpolation that I am implementing right now in R, the minimum appears to be at x0 = (4.230490, 68.52776); fval = -175.7959 I certainly would be interested to hear from other reasonable locations of a minimum, as this may be a good test case. -- Hans Werner > x y z > 4.1 60 -152.1719593 > [ ... ] > 4.35 90 -163.8389615 > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.