How to assign default values to function inputs

I have a function with some required inputs,

heatContent = function(swRadiation, lwRadiation)

If the user passes in [] for any of the inputs, I would like to substitute default values (swRadiation=100 or lwRadiation=50). Also if the user only passes in 1 input, I would substitute in lwradiation=50 for the second input. I believe I can use inputparser to do this, but the following gives an error (Undefined function or variable 'lwRadiation'). I could write a long chain of if/elseif statements but suspect there is a more compact way.

p = inputparser; 
addOptional(p,'swRadation',50);
addOptional(p,'lwRadiation',100);

Answer 1

[Jan]

How should the code decide which input was given, when you provide one input only?

The inputParser is a powerful tool. But hard coding is not complicated here:

function heatContent = function(swRadiation, lwRadiation)
switch nargin
  case 0
    swRadiation = [];
    lwRadiation = [];
  case 1
    lwRadiation = [];
  case 2
  otherwise
    error('2 inputs are accepted.')
end
if isempty(swRadiation)
  swRadiation = 50;
end
if isempty(lwRadiation)
  lwRadiation = 100;
end
...

The inputParser expects name-value pairs to identify the inputs. This allows to change the order of the inputs and you can provide the 2nd input only without ambiguities.

[K E]

It is good to know that there is not in fact a shortcut via inputparser, and that if statements are a fine approach.