fitting to experimental data

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Tue, 08/30/2011 - 12:59 pm

Hello,

I have a set of experimental data (mole fractions of a compound (a certain phase)for a range of pressures and temperatures).

I have also written a function that computes the equilibrium between two phases of the compound. THe function includes a interaction parameter (of the form c1+tr*c2^c3+....). The parameter has eight coefficients (c1-c8) and is reduced temperature dependent (tr).

I would like to optimize the interaction parameter so that the mole fraction of a compound (of a certain phase) match those of the experimental data.

Is there a way in igor to achieve this?

Thanks very much in advance for any help.
Copy this command, paste it into Igor's command line and press Enter:

DisplayHelpTopic "Curve Fitting"

Once you have digested that (it's pretty big) it's not uncommon for data like yours to be organized in the form of multiple data sets. For that you may find Global Fitting to be helpful. Pull down the File menu and select Example Experiments->Curve Fitting->Global Fit Demo.pxp.

And you may benefit from the Getting Started help, including the Guided Tour, which is a major part of Getting Started. It's the first item in the Help menu.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

August 30, 2011 at 01:16 pm - Permalink