MATLAB: Anonymous function issue

anonymous function

Hi guys I need help with this issue
I am using this calculated formula
(((h(n)/3)*(f(c)+Ie+Io+f(d))))
which equals to
(x*exp(1/2 - x))/24 + (x*exp(1/4 - x))/12
where, f=@(y) (x*y*exp(y-x)),
then i wrote it as
g =  @(x)(((h(n)/3)*(f(c)+Ie+Io+f(d))))
then i tried which is in my code
>> g(2)
ans =
(x*exp(1/2 - x))/24 + (x*exp(1/4 - x))/12
I am wondering why it gives me the same formula without substituting x as 2

Best Answer

You use x as the dummy parameter for g, but you do not use x within the formula.
In order for your code not to crash you would have to have defined x as symbolic or given x a value before you defined f, and it would be that symbol or that value that would be "captured" in the definition of f.
For example,
x = 5;
f = @(y) 3 + x + y;
x = 19;
f(7)
then the value "x = 5" gets "captured" when f is defined so even though you changed x after you define f, the value 5 will be used not the current x.
Related Question