Is there a simple way to condense the following codes?

function greek=OptionGreeks(opt,arg1,arg2,arg3,arg4,arg5)

              seed=rng;

              if nargin==3
                  greek1=opt.opt1.OptionGreeks(arg1, arg2);
                  rng(seed);
                  greek2=opt.opt2.OptionGreeks(arg1, arg2);
              elseif nargin==4
                  greek1=opt.opt1.OptionGreeks(arg1, arg2, arg3);
                  rng(seed);
                  greek2=opt.opt2.OptionGreeks(arg1, arg2, arg3);
              elseif nargin==5
                  greek1=opt.opt1.OptionGreeks(arg1, arg2, arg3, arg4);
                  rng(seed);
                  greek2=opt.opt2.OptionGreeks(arg1, arg2, arg3, arg4);
              else
                  greek1=opt.opt1.OptionGreeks(arg1, arg2, arg3, arg4, arg5);
                  rng(seed);
                  greek2=opt.opt2.OptionGreeks(arg1, arg2, arg3, arg4, arg5);
              end

              greek=greek1-greek2;
end

Above are my codes. opt is a SpreadOption class that has properties opt1 and opt2, which are Option class. Function SpreadOption.OptionGreeks() calls function Option.OptionGreeks() that accepts different number of input arguments.

I'm wondering if there's a way to condense the codes.

Also, I'm wondering what the easiest way is to customize my input argument, like opt.OptionPrice(S=3610, method='binomial tree', brunches=100000)? (just like python and R do)?It seems not convenient since MATLAB cannot overload/override a certain function.

Answer 1

[OCDER]

Does this work? https://www.mathworks.com/help/matlab/ref/varargin.html

function greek = OptionGreeks(opt, varargin)
if length(varargin) > 5; varargin = varargin(1:5); end
seed = rng;
greek1=opt.opt1.OptionGreeks(varargin{:});
rng(seed);
greek2=opt.opt2.OptionGreeks(varargin{:});
greek=greek1-greek2;

[Guixin Liu]

Wow! That's EXACTLY what I'm looking for.

Many thanks and now my codes look much cleaner!

[OCDER]

You're welcome! And I guess you'll be discovering varargout shortly too:

https://www.mathworks.com/help/matlab/ref/varargout.html

[Guixin Liu]

I do not need 'varargout' for now, but I'm thinking about another question. In some other coding languages, I can write a function as

function OptionGreeks(S, greek_name, method='numerical', simTimes=1e6) 
% function body
end

and I can call the function using syntax

OptionGreeks(102, 'delta', method='analytical')

or

OptionGreeks(102, 'delta', simTimes=1e7)

Note that they both have 3 input arguments. So I'm wondering whether there's a convenient way for Matlab to realize it.

I'd be grateful for any of your ideas.

[Walter Roberson]

MATLAB does not support variable=value options.

See https://www.mathworks.com/help/matlab/matlab_prog/input-parser-validation-functions.html for the standard input parsing routines.