# integrate

Integrate `cfit` object

## Syntax

`int = integrate(fun,x,x0)`

## Description

`int = integrate(fun,x,x0)` integrates the `cfit` object `fun` at the points specified by the vector `x`, starting from `x0`, and returns the result in `int`. `int` is a vector the same size as `x`. `x0` is a scalar.

## Examples

Create a baseline sinusoidal signal:

```xdata = (0:.1:2*pi)'; y0 = sin(xdata);```

```noise = 2*y0.*randn(size(y0)); % Response-dependent % Gaussian noise ydata = y0 + noise;```

Fit the noisy data with a custom sinusoidal model:

```f = fittype('a*sin(b*x)'); fit1 = fit(xdata,ydata,f,'StartPoint',[1 1]);```

Find the integral of the fit at the predictors:

`int = integrate(fit1,xdata,0);`

Plot the data, the fit, and the integral:

```subplot(2,1,1) plot(fit1,xdata,ydata) % cfit plot method subplot(2,1,2) plot(xdata,int,'m') % double plot method grid on legend('integral') ```

Note that integrals can also be computed and plotted directly with the `cfit` `plot` method, as follows:

`plot(fit1,xdata,ydata,{'fit','integral'})`

The `plot` method, however, does not return data on the integral.