nlinfit (Statistics Toolbox)

Nonlinear least-squares data fitting by the Gauss-Newton method.

Syntax

[beta,r,J] = nlinfit(X,y,'model',beta0)

Description

beta = nlinfit(X,y,'model',beta0) returns the coefficients of the nonlinear function described in 'model'.

'model' is a user-supplied function having the form:

. It returns the predicted values of y given initial parameter estimates,

, and the independent variable, X.

The matrix, X, has one column per independent variable. The response, y, is a column vector with the same number of rows as X.

[beta,r,J] = nlinfit(X,y,'model',beta0) returns the fitted coefficients, beta, the residuals, r, and the Jacobian, J, for use with nlintool to produce error estimates on predictions.

Example

load reaction
betafit = nlinfit(reactants,rate,'hougen',beta)

betafit =
    1.2526
    0.0628
    0.0400
    0.1124
    1.1914