Help with Varargin
9 views (last 30 days)
Show older comments
I have a function called MySolve and i am looking to adapt it to use Varargin.
As far as i am aware Varargin allows defaults for parameters to be set. but can be over-ridden if an input is given. I am having trouble understanding the syntax for using Varargin, here is the function MySolve.m that i have written:
function [x,converged]=MySolve(f,x0,tol,maxit)
%Set Converged intial value to 0 (false)
%Set initial value of x as x0
converged=0;
x=x0;
%run a loop from 1 to maxit
for k=0:maxit
x1=x;
r=f(x);
J=MyJacobian(f,x,1e-6);
x=x-(J\r);
if(max(abs(x-x1)))<tol && max(abs(f(x)))<tol
converged=1;
end
end
I am looking to have defaults for tol and maxit as 1e-10 and 100 respectively.
any help is much appreciated.
0 Comments
Accepted Answer
Sarah Wait Zaranek
on 23 Mar 2011
I would suggest the following. This way, the input values are reflected. Hardwire the inputs you definitely want, and use varargin to hold the optional inputs.
function [x,converged]=MySolve(f,x0,varargin)
optargin = size(varargin,2);
if optargin == 0
tol = 1e-10;
maxit = 100;
elseif optargin == 1
tol = varargin{1};
maxit = 100;
else
tol = varargin{1};
maxit = varargin{2};
end
2 Comments
More Answers (1)
Jarrod Rivituso
on 23 Mar 2011
Actually you could use nargin to do this. Essentially, nargin tells you the number of the arguments, and you can use it add some code at the beginning of your function to compensate for missing inputs.
An example:
function twoInputs(x,y)
if nargin == 0
x = 1;
y = 2;
end
if nargin == 1
y = 2;
end
disp(x)
disp(y)
0 Comments
See Also
Categories
Find more on Loops and Conditional Statements in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!