MATLAB: Enhancing a Function so that it can be called using the following syntax

narginrandom number generatorsyntax

HELP. I want to be able to call the below function using the following syntax
    working_program
    working_program(n)
    working_program(n,m)
    working_program(n,'method')
    working_program(m,n,'method')
If a user inputs no values a single random number should be generated If a user inputs (n), the function should return a n x n square matrix If a user inputs (m,n), the function should return a m x n matrix* * * *
    function y = working_program(n, method)
    switch method
        case 'NR' %parameters from Numerical Recipes book
            a=1664525;
            b=1013904223;
            c=2^32;
        case 'RANDU' %RANDU generator
            a=65539;
            b=0;
            c=2^31;
        otherwise
            error('Invalid method')
    end
    seed=mod(a*etime(clock,[1993 6 30 8 15 0])+b,c);
    y= zeros(n,1);
    y(1)= seed;
    for i=2:n
        y(i)=mod(a*y(i-1)+b,c);
    end
    y=y/c; %normalizing so all values are between 0 and 1

Best Answer

You use nargin to check how many arguments were passed and ischar or isnumeric to test whether they're strings or numeric, e.g: (there are many ways to do this, you could also use varargin)
y = function working_program(n, arg1, method)
  switch nargin
    case 0
      n=1; m=1; method = 'RANDU';
    case 1
      m=n; method = 'RANDU';
    case 2
      if ischar(arg1)
        m=n; method = arg1;
      else
        m=arg1; method = 'RANDU';
      end
    case 3
      m=arg1;
   end
   %the rest of your code
end
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