3D Plotting and Functional Fit

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Fri, 08/14/2009 - 04:20 pm

Hi all, I've got a few quick questions about 3d plotting in IGOR. I checked the help browser but it didn't help too much. Here's where I'm stuck:

1. Given a set of data points in 3 dimensions (x, y, and z), how does one plot these corresponding data points in 3d?

2. How does one find the surface (or equation) that fits those data points?

Thanks in advance!

p.s. all of the data is continuous and relatively smooth on our given interval, which should make my job a little easier.
Kramer51 wrote:
Hi all, I've got a few quick questions about 3d plotting in IGOR. I checked the help browser but it didn't help too much. Here's where I'm stuck:

1. Given a set of data points in 3 dimensions (x, y, and z), how does one plot these corresponding data points in 3d?

You use Gizmo for that, but just how you use it depends on the format of your data. Look at Windows->New->3D Plots and select the #D Help topic in that menu. There are also video tutorials for 3D graphics (AG is a pioneer in this!); see the links at the bottom of http://www.wavemetrics.com/products/igorpro/creatinggraphs/3dandvolume….

Kramer51 wrote:
2. How does one find the surface (or equation) that fits those data points?


If you mean "fit a bunch of random equations to find one that looks like my data" Igor doesn't do that. Polynomials are popular for cases where you don't have a physical model to guide you.

If you mean, "I have a model but don't know how to do a multivariate fit", check out the help here by copying this command and pasting it into Igor's command line:

DisplayHelpTopic "Fitting to a Multivariate Function"

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

August 17, 2009 at 09:17 am - Permalink