How do I define a piecewise function using special conditions?

Hello, thank you for helping me. I am using a script to calculate the dft of a function entered simbolically in terms of the variable "n"using the following:

    syms n;
    f = input('Enter the function\n');

Everything works fine so far, my question is whether I can enter the following piecewise function with special conditions as an argument to the script and how:

f[n]= 3 for n even.

f[n]= -2 for n odd.

Thank you again.

[John D'Errico]

Why do you need symbolic here?

And how is a function that is defined ONLY on the integers a piecewise function?

Why are you trying to input a function using input? Time for you to learn how to define a function.

Finally, learn how to define an index, or for that matter, the arguments to a function. f[n] is NOT valid syntax in MATLAB.

Clearly your most important project is to read the basic getting started tutorials in MATLAB.

Answer 1

[Andrei Bobrov]

f = input('Enter the function: ','s') % enter expression: 3-5*rem(n,2) 
f = str2func(['@(n)',f])

use f:

>> f(1:10)
ans =
    -2     3    -2     3    -2     3    -2     3    -2     3