fminbnd

Syntax

x = fminbnd(@func,interval)

x = fminbnd(@func,interval,options)

[x,fval,info,output] = fminbnd(...)

Inputs

func

The function to minimize.

interval

A two-element vector containing the interval on which to minimize.

Type: double

Dimension: vector

options

A struct containing option settings.

See optimset for details.

Outputs

x

The location of the function minimum.

fval

The minimum of the function.

info

The convergence status flag.

info = 1

Function value converged to within tolX.

info = 0

Reached maximum number of iterations or function calls.

output

A struct containing iteration details. The members are as follows:

iterations

The number of iterations.

nfev

The number of function evaluations.

xiter

The function values of the interval end points at each iteration.

fvaliter

The interval end points at each iteration.

Examples

function y = func(x)
    y = -log(x) / x;
end

interval = [1, 6];
[x,fval] = fminbnd(@func, interval)

x = 2.71828183
fval = -0.367879441

function y = func(x, offset)
    y = -log(x) / x + offset;
end

handle = @(x) func(x, 2);
[x,fval] = fminbnd(handle, interval)

x = 2.71828183
fval = 1.63212056

Comments

fminbnd implements Brent's method for minimization without derivatives.

Options for convergence tolerance controls are specified with optimset.

To pass additional parameters to a function argument, use an anonymous function.