optional input arguments with dynamic variable numbering matlab

Question

I'm trying to write a function in MATLAB, having optional input arguments and the function is called in for loop, I want two things:

• firstly, optional input arguments i.e no need of sequence of inputs
• secondly, whenever the function is calling, it numbers the variable name so that no conflict is left, it is required as no output is deserved.

My function:

function mYfunc(a,b,c,d,e,f)
var1= 'some string';
% for numbering, may be use of eval(['var' num2str(1)]) but how the function call is identified, 
% i.e in same loop function calls again, then iteration is identified

if nargin >= 3
 %some operation
end

if nargin >= 4
  %some operation
end
if nargin >= 5
   %some operation
end
if nargin >= 6
   %some operation
end
end

The for loop:

for i=1:3
mYfunc(a,b,c,d,e,f); %first call, var1 is expected
mYfunc(a,b,e,f); %second call, var2 is expected
mYfunc(c,d,e,f); %third call, var3 is expected
mYfunc(a,b,c,d); %fourth call, var4 is expected
mYfunc(c); % fifth call, var5 is expected
end

Answer 1

You may be able to use varargin along with your if statement to assign inputs to certain variable names (e.g. if nargin==4, b=varargin{2}; end or whatever you want).

There is a slight learning curve, but for the most versatile solution I also suggest you look into using MATLAB's inputParser, which gives you all the flexibility you need. It also allows you to specify inputs by a name (string). See also this description of inputParser.

Answer 2

I don't quite understand your question, but probably the inputname function can help you. It tells you the name of a certain argument when the function is called.

http://www.mathworks.com/help/matlab/ref/inputname.html