Re: Data interpolation

*To*: mathgroup at smc.vnet.net*Subject*: [mg96247] Re: Data interpolation*From*: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>*Date*: Tue, 10 Feb 2009 05:50:41 -0500 (EST)*References*: <gmp11b$c6r$1@smc.vnet.net>

hemanth, ListInterpolation will do what you want nicely. Cheers -- Sjoerd On Feb 9, 12:37 pm, hemanth korrapati <hemanthkorrap... at gmail.com> wrote: > Hi, > > I have some 3D point data acquired through a laser range finder. The > data is sparse. I need to construct a height field out of this data > and as a part of this i have to interpolate heights at some locations > {x,y} where the actual data is not available. > I want to use B-splines. But it seems that B-splines require uniformly > distributed control points, which is not the case with my data. > My data cannot form a uniform table which is required by the > BSplineSurface function if I sort my data. > > for some data i got the following error: > Interpolation::indim: The coordinates do not lie on a structured > tensor product grid. >> > > So I started using the "ListDensityPlot" function which does a linear > interpolation of the data. The interpolation is sufficiently good. But > I would like to get an output consisting of list of tuples like > {x,y,InterpolatedHeight} at the desired {x,y} locations. Right now I > can only see the plot but cannot get the interpolated heights at > desired locations({x,y}). > > Now I have three questions: > 1) how do i make my data usable for splines in mathematica ? > 2) how do i get the interpolated values at desired {x,y} using > "ListDensityPlot" function ? > 3) Is there a better way other than the above two methods to > interpolate the missing data ? > > Thank you