How do I fix: "Undefined function 'fit' for input arguments of type 'function_handle'."?

I'm not entirely understanding the reason why the follow code doesn't work:

close all; clear all;

x = [2 4 6 8 10];

y = [0.18 0.45-.05 0.85-.1 1.35-.15 2-.2];

fun = @(a,b,c,x) -sqrt(a^2-(x-b).^2)+c;

guess = fun(15,0,15,x); % fun(a,b,c,x)

plot(x,guess,'r:')

fittedmodel = fit(x',y',fun,'StartPoint',[15 0 15])

plot(fittedmodel,'r-');

When I run the code I get the following error:

Undefined function 'fit' for input arguments of type 'function_handle'.

How can I fix this?

Thank you.

Answer 1

[Walter Roberson]

Which MATLAB version are you using?

Ensure that you have the Curvefitting toolbox installed and licensed. Use

which -all fit

[Jacob]

I'm using version 2013a.

When I use 'which -all fit' I have an output showing that I have the following libraries within my toolbox:

gmdistribution method
ProbDistUnivParam method
NaiveBayes method

Does this mean I'm missing some libraries to use the fit function I would like to use or do I have to readjust my parameters to those methods?

[Walter Roberson]

It does appear that you are missing the Curvefitting Toolbox.