OriginLab Corporation - Scientific Graphing and Data Analysis Software - 2D graphs, 3D graphs, Contour Plots, Statistical Charts, Data Exploration, Statistics, Curve Fitting, Signal Processing, and Peak Analysis

Quick Start

Nonlinear fitting in Origin is performed using the NonLinear Fitting (NLFit) dialog box. The NLFit tool contains more than 200 built-in fitting functions used in many different disciplines.

The NLFit tool can be opened from the menu by selecting Analysis: Fitting: Nonlinear Curve Fit. Once opened, you may be able to fit your data with as few as three mouse clicks:

  1. Select a function Category.
  2. Select a fitting Function.
  3. Click the Fit button.
Image:Quick Start-1.png

This short tutorial demonstrates the basic NLFit process:

  1. Click the Import ASCII button Image:Button_Import_Single_ASCII.png on the Standard toolbar.
  2. Browse to the \Samples\Curve Fitting\ folder. Select Gaussian.dat and then click Open.
  3. This imports the ASCII file into the active worksheet.
  4. Highlight column B and select Analysis: Fitting: Nonlinear Curve Fit from menu to bring up the NLFit dialog.
  5. In the settings area of upper panel, select Category = Origin Basic Functions and Function = Gauss fitting function.
  6. Click the Fit button to perform the fit.

This is a simple case. Note that the NLFit dialog has many more controls that allow you to further customize the fitting procedure and to analyze more complex datasets. The following section discusses the use of the NLFit dialog box in more detail.