Defining persistent variables in a function

I've a function that is called multiple times

function fun()
persistent x y z
if isempty(x)
x = %
end
if isempty(y)
y = %
end
if isempty(z)
z = %
end
end

How can I do better without having multiple if statements? Can we vectorize the variables and check once?

Any suggestions will be really helpful

Answer 1

[Rik]

You can use use this:

function fun()
persistent x y z
if isempty(x)
x = %
y = %
z = %
end
%rest of your function 
end