Data Analysis (Damped Oscillations) Using the Genfit Function©
R. D. Poshusta
Department of Chemistry
Washington State University
Pullman, WA 99164-4630
United States
mail to: poshustr@mail.wsu.edu

This document is an example of how to use the Mathcad Genfit function to do a general least squares fit of a model function to experimental data. The damped oscillator is the model function used here. The uncertainties of the fitting parameters are computed by using the second derivative matrix. The "error matrix" is reciprocal of the second derivative matrix. From the error matrix the uncertainties in the fitting parameters are obtained as described by Bevington ["Data Reduction and error analysis for the physical sciences" P.R. Bevington p 246; McGraw-Hill, 1969]. This document compliments the approach taken in "van der Waals and Redlich Kwong: Fitting Two Parameter Equations to Gas Data" by Theresa Julia Zielinski. Students can adopt this document as a model for writing their own curve fitting documents. The author thinks that this method is general enough to work for many mathematical models. Faculty and students can generate additional data sets for damped oscillations with the sim_dmp.mcd file. Additional data sets for damped oscillations help students to practice the concepts and provides faculty with an assessment strategy.
Editor's Commentary
Audiences: Upper-Division Undergraduate
Pedagogies: Computer-Based Learning
Domains: Analytical Chemistry, Laboratory Instruction, Physical Chemistry
Topics: Chemometrics, Mathematics / Symbolic Mathematics
File NameDescriptionSoftware TypeSoftware Version
sim_dmp.pdf Read-Only Document
sim_dmp.zip JCE Computational Documents
JCE JCE Subscribers only: name and password or institutional IP number access required.
Proshusta, R. D. J. Chem. Educ. 2005, 82, 1101
Comments to: Ron Poshusta at poshustr@mail.wsu.edu
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