User`s guide

integrate

4-117

4integrate

Purpose Integrate a fit result object

Syntax inty = integrate(fresult,x,x0)

Arguments

Description

inty = integrate(fresult,x,x0) integrates the fit result object fresult at

the values specified by

x starting from x0, and returns the result to inty. The

fresult object is a fit result object generated by the fit function. x is a scalar

or column vector and

inty is the same size as x. x0 is a scalar.

Example Create a noisy sine wave on the interval [-2π, 2π].

rand('state',0);

x = (-2*pi:0.1:2*pi)';

y = sin(x) + (rand(size(x))-0.5)*0.2;

Create a custom fit type, and fit the data using reasonable starting values.

ftype = fittype('a*sin(b*x)');

fit1 = fit(x,y,ftype,'startpoint',[1 1]);

Calculate the integral for each value of x starting at -2*pi

inty = integrate(fit1,x,x(1));