MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Intepolation of an array with missing points

  • To: mathgroup at
  • Subject: [mg62363] Re: [mg62323] Intepolation of an array with missing points
  • From: "Jose Luis Gomez" <jose.luis.gomez at>
  • Date: Tue, 22 Nov 2005 04:42:04 -0500 (EST)
  • Sender: owner-wri-mathgroup at

Hello James 

One possibility could be to use the imsUnstructuredPlot3D and the
imsUnstructuredContourPlot, they are designed within the context of the
Finite Elements Method, where there appears a similar problem to the one you
have: the data to be plotted is not in a rectangular grid, but it is in an
unstructured grid. imsUnstructuredPlot3D and imsUnstructuredContourPlot are
included in the IMTEK Mathematica Supplement (IMS)

IMS is a free Add-On package to Mathematica. You can download it free from: 
After you have downoloaded it, installed it and rebuild Mathematica's help
index (as explained during the installation) then you can go to your
Mathematica's help
browser->Add-ons->Imtek->Utilities->Graphics->Unstructured Plot; there you
will see examples of how to use this commands, and IMS has also its own
mailing list where you can also ask questions to more expirienced users and
the creators of IMS.

Hope this helps

José Luis

-----Mensaje original-----
De: dkjk at [mailto:dkjk at] 
Enviado el: Sábado, 19 de Noviembre de 2005 10:19 p.m.
Para: mathgroup at
Asunto: [mg62323] Intepolation of an array with missing points


I have an array representing the heights of a surface over the x-y
plane. Unfortunately, the heights at several points are unknown so have
been replaced by empty strings. For an example, see

arr = Import["output.csv"] // MatrixForm

My ultimate goal is to create an interpolating function of this data
which will allow me to produce a contour plot. As a very inexperienced
user of Mathematica, my initial thoughts have been someting like this:

1. Convert arr to an list of 3-tuples, ignoring the empty entries. (not
sure how to do this)
2. Use Interpolation to create an InterpolatingFunction which can be
plotted in ContourPlot.

Does anyone know of a simple method to achieve 1. and whether or not 2.
will work in this case?




IMTEK Mathematica Supplement (IMS)

IMS mailing list
IMS at

  • Prev by Date: Re: statistics questions
  • Next by Date: Re: How to read a data file in text format?_from a new learner
  • Previous by thread: Re: Intepolation of an array with missing points
  • Next by thread: Re: Intepolation of an array with missing points