DataFit

DataFit is a tool used to perform nonlinear regression (curve fitting), statistical analysis and data plotting. What sets DataFit apart from similar curve fitting and regression programs is its ease of use. DataFit is driven by a well-designed graphical interface, so there are no complicated instructions to remember and no programs to write. Data entry is achieved through a standard spreadsheet interface, which supports ASCII and ODBC data source import, as well as cutting and pasting data from the clipboard. With DataFit, you can perform linear or nonlinear regression on data containing up to 20 independent variables. You can choose from more than 600 pre-defined equations, which are commonly used in statistical, scientific and engineering applications, or create your own equations. Solved equations are sorted according to goodness-of-fit. DataFit also includes forward selection, backward elimination, stepwise selection and manual variable selection modes to help determine which independent variables should be included in your regression model for multivariate datasets. Results include completely customizable 2D and 3D plots, fitted parameters with confidence intervals, input vs. estimated data and goodness-of-fit information. Plots can be saved as templates, which allows them to be applied to new plots in order to instantly give them your own custom appearance. Data tables, supporting interpolation and extrapolation (projections), can be exported in ASCII, Excel or HTML format. You can also automatically export source code in BASIC or C to utilize any solved equation in a program that you have written. Macro capability allows curve fitting operations to be performed non-graphically, either in batch mode or by calling DataFit from an external program. With the combination of an intuitive interface, online help and wide range of features, it is a tool that is used effectively by both beginners and experts.