MATLAB: Passing arguments to a function

Question

function val = sum(a,b)
 default('a',1); % uses a function from file exchange
 default('b',20);
 val = a+b
end

I want to pass only the second argument and use the default for first,a. Something like below,

val = sum(b=2)

How can I do this in MATLAB?

Answer 1

One way of doing this is to pass an empty argument, e.g., mySum([], 2) or mySum(2, []). So, you can add the following conditions:

function myVal = mySum(a, b)
 if isempty(a)
     a = 1;
 end
 if isempty(b)
     b = 20;
 end
 myVal = a+b;
end