MATLAB: ~ in function definition

function definition statement

Looking at some previous code I found a function that is defined as function(x,y,z]=fun(~,~,~)

what are the ~ doing in the input list?

The function input will be ignored. It is described here:

That happens automatically with a normal function definition.

Only anonymous functions may be defined in the command window:

 >> fun = @(x,y,z)-9*x - 10*y+ z*(-log(100-x-y)-log(x)-log(y)-log(50-x+y));
 >> fun(1,2,3)
 ans =
          -56.599051375363

Other function types (those defined using the keyword function) must be defined in an Mfile.