Nonlinear regression analysis - CurveFitter CurveFitter program performs statistical regression analysis to estimate the values of parameters for linear, multivariate, polynomial, exponential and nonlinear functions. The regression analysis determines the values of the parameters that cause the function to best fit the observed data that you provide. This process is also called "curve fitting". Quickly Find the Best Equations that Describe Your Data: Curvefitter gives engineers and researchers the power to find the ideal model for even the most complex data, by putting a large number of equations at their fingertips. Curvefitter's built-in library includes a wide array of linear and nonlinear models from simple linear equations to high order polynomials. Curve fitter's state-of-the-art data fitting includes the following capabilities: *A 38-digit precision math emulator for properly fitting high order polynomials and rationals. *A robust fitting capability for nonlinear fitting that effectively copes with outliers and a wide dynamic Y data range. Graphically Review Curve Fit Results: Once your data have been fit, Curvefitter automatically sorts and plots the fitted equations by the statistical criteria of Standard Error. You can preview your graph and output publication-quality graphs in several different configurations. A residual graph as well as parameter output is generated for the selected fitted equation. Data, statistical and numeric summaries are also available from within the Review Curve Fit window. With All This Power, it's’ Still Easy to Use: Curvefitter takes full advantage of the Windows user interface to simplify every aspect of operation -- from data import to output of results. Import data from many popular file formats including Excel, Lotus and ASCII. Once your data are in the editor, select a pre-defined equation and start the automatic fitting process with a single mouse click.