Calling a function with 2 inputs using only a single input

I have a function with inputs a and b and when i tried to call the function with one input a and use the inbuilt function isempty(b) its showing error as not enough input arguments. How can I correct this.

function out = function_name(a,b)
if ~isempty(b)
  b = 0.1;
end

Answer 1

[Adam]

It depends how you want to handle it. Do you want 'b' to be an optional argument or do you want to force the caller to always give a value for b and support [] as a a value for it?

As the final argument to a function there is not usually much point doing the latter so I would just do e.g.

function out = myFunction( a, b )

narginchk( 1, 2 )

if exist( 'b', 'var' )
   % Do some validation - optional I suppose!!
else
   b = 0.1;
end

If you wanted to support 'a' being optional then you could do this by allowing [] to be a valid input and would do like above, but include

if exist( 'a', 'var' ) && ~isempty( a )

Answer 2

[Rik]

You need to test for existence, not for being empty, as someone could still use an empty input.

function out=function_name(a,b)
if ~exist('b','var')
    b=0.1;
elseif isempty(b)
   error('b should not be empty')
end
out=a*b;
end

You can also use nargin to check the number of input arguments.

Answer 3

[Govind Sankar Madhavan Pillai Ramachandran Nair]

thank you very much for your answers, it helped me

[Rik]

You're welcome. The best way to thank us is to accept the answer that works best and give other working answers a vote.