What is the problem with the heaviside function?

fun =

    @(p,x)p(1)*heaviside(x-p(2))

Undefined function 'heaviside' for input arguments of type 'double'.

Answer 1

[Star Strider]

Your function works for me. Do you have the Symbolic Math Toolbox?

If you don’t substitute a call to this one for the heaviside call:

hvsd = @(x) [0.5*(x == 0) + (x > 0)];

I tested both, they give equivalent results.

[Mr M.]

Symbolic Math Toolbox for what? for the heaviside function??

[Star Strider]

Yes. The heaviside function is only in the Symbolic Math Toolbox. My function provides the same results, so you can use it instead. I abbreviated its name to ‘hvsd’ be sure it didn’t overshadow heaviside on my computer so I could test both of them. You can obviously name it whatever you want.

Answer 2

[Thorsten]

The error means that Matlab cannot find the heaviside function. Try

 which heaviside

to locate the function. The heaviside function is part of the Symbolic Math Toolbox. If you do not have this TB, you can write your own heaviside function

function y = heaviside(x)
y = (x > 0) + 0.5*(x == 0);

[Dief Gerard]

@Thorsten Thanks for your answer. It helped me debug my code.