# 3.34 FAQ-263 How to include integrate in my fitting function

Last Update: 2/4/2015

Origin allows you to define a fitting function which involves an integral. Note that since an integral-based fitting function computes the integral for each iteration, the fitting procedure may be time-consuming.

Please refer to the following tutorials for how to define such functions:

Keywords: integrate, integral, fitting, Origin C, LabTalk, NAG