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Re: Data interpolation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg96327] Re: Data interpolation
  • From: dh <dh at metrohm.com>
  • Date: Wed, 11 Feb 2009 05:24:49 -0500 (EST)
  • References: <gmp11b$c6r$1@smc.vnet.net> <gmrm4r$9mr$1@smc.vnet.net>


Hi Sjoerd,

to my knowledge thats wrong. ListInterpolate can only interpolate data 

on a grid. Otherwise, please give an example.

Daniel





Sjoerd C. de Vries wrote:

> 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

> 

> 




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