How to use the "parse" function to create optional function inputs

Hello,

I am trying to use "parse" to create optional function inputs. Tried to replicate examples in the documentation (see below and attached) but I get the "too many arguments" error. Any idea? Thanks

my code below:

----------------

function []=testFun(A,varargList)

p = inputParser;

defaultNorm = 'L2';
validNorms = {'L1','L2'};
checkNorm = @(x) any(validatestring(x,validNorms));

addOptional(p,'lambda',0,@isnumeric)
addOptional(p,'norm',defaultNorm,checkNorm)

parse(A,varargList{:})

lambda = p.Results.lambda;
norm = p.Results.norm;

disp('input1 = ')
disp(A)
disp('lambda = ')
disp(lambda)
disp('norm = ')
disp (norm)

end

Answer 1

[Francois Steiner]

Hello,

I changed the name to varargin, but it still doesn't work, I have an error on the "parse" line. What am I missing?

See code below.

Thanks for your help.

François

function []=testFun(A,varargin)

p = inputParser;

defaultNorm = 'L2';
validNorms = {'L1','L2'};
checkNorm = @(x) any(validatestring(x,validNorms));

addOptional(p,'lambda',0,@isnumeric)
addOptional(p,'norm',defaultNorm,checkNorm)

parse(A,varargin{:})

lambda = p.Results.lambda;
norm = p.Results.norm;

disp('input1 = ')
disp(A)
disp('lambda = ')
disp(lambda)
disp('norm = ')
disp (norm)

end

[Walter Roberson]

You have to pass p as the first argument to parse

[Francois Steiner]

It works! Thanks Walter for your patience.

Below corrected code in case it can be of help to anyone.

All the best,

François

function []=testFun(A,varargin)

p = inputParser;

defaultNorm = 'L2';
validNorms = {'L1','L2'};
checkNorm = @(x) any(validatestring(x,validNorms));

addRequired(p,'A',@ischar);
addOptional(p,'lambda',0,@isnumeric)
addOptional(p,'norm',defaultNorm,checkNorm)

parse(p,A,varargin{:})

lambda = p.Results.lambda;
norm = p.Results.norm;

disp('A = ')
disp(A)
disp('lambda = ')
disp(lambda)
disp('norm = ')
disp (norm)

end

[Guillaume]

meta-comment: It's kind of bad form to accept your own answer to your own question, particularly as your answer is actually more of a comment on Walter's answer.

[Walter Roberson]

Actually it is okay to accept your own Answer if you were the one who figured out the solution.

Answer 2

[Walter Roberson]

The variable name has to be varargin to be recognized as special, not varargList

[Francois Steiner]

That simple - I thought any name would do. I really struggled with this one, many thanks for your help Walter, much appreciated. All the best, François