Calling a function without an Output argument

Hi Programmers,

I have a function that plots the phase and magnitude of my signal.

I want this function to plot only the magnitude if no ouput argument is provided when the function is called.

Y = Myplot (a,b)
Y = figure(1)
subplot(2,1,1)
stem (a)

subplot(2,1,2)
stem (b)

% I want to plot only stem (a) when the function is called without the
% output argument.

Myplot (a,b)
stem (a)

Answer 1

[Adam Danz]

Use nargout to determine the number of output arguments.

if nargout==0
    % do something
elseif nargout < 2
    % do something else
end

[Telema Harry]

Thank you.

[Adam Danz]

Note that if the function call is not followed by a semicolon to suppress the output or if the function is used as an input in an array or in another function, then even if an output isn't explicitly assigned nargout will return 1.

For example,

T = [1, 2, f(n)];

[Telema Harry]

I modified the code slightly and it gave me the intended result.

if nargout==0

% do something

elseif nargout > 0

% do something else

end

Thank you for your help.

[Adam Danz]

This can be simplified to

if nargout == 0

else

end

Answer 2

[David Hill]

Change the number of input arguments instead

function y=Myplot(varagin)
y=figure;  
  if nargin==2
      subplot(2,1,1);
      stem(varagin{1});
      subplot(2,1,2);
      stem(varagin{2});
  else
      stem(varagin{1});
end