Information • Textbooks • Media • Resources
Mathcad in the Chemistry Curriculum
Non-Linear Least-Squares Regression: NonLinearLeastSquares.mcd and nonlinear.prn
W
Sidney H. Young and Andrzej Wierzbicki, Department of Chemistry, University of South Alabama, Mobile, AL 36688
Nonlinear least-squares regression is often required in the physical chemistry laboratory. It is especially important for fitting functions that cannot be linearized. This template demonstrates various implicit and explicit methods for de-
edited by
Theresa Julia Zielinski Monmouth University West Long Branch, NJ 07764
termining of the parameters of the regressed curve obtained by nonlinear curve-fitting. Through this worksheet students will be able to obtain the standard deviation of fit and the standard deviations of the parameters. Residual analysis is used to demonstrate techniques of removing bad data points from the fit. Data may be read into the template by using a Read statement. After minor editing the template can be used for a variety of applications in the student and research laboratories. As in Linear Least-Squares Regression (above), parameters can be tested to see if their addition to a model is statistically significant.
JChemEd.chem.wisc.edu • Vol. 77 No. 5 May 2000 • Journal of Chemical Education
669
