CODEWITHSUNDEEP
matlabparsinginputoctave
babelproofreader
babelproofreader

Reputation: 552

addOptional in Octave 5.1.0 is failing when parsing function input

This is a follow up to an earlier question of mine here. Although the immediate problem in said question has been solved by use of addParamValue and the recommendated function, there is still an issue with using addOptional. The code flow is:

parser = inputParser() ;
parser.FunctionName = "mdDelay" ;
defaultMaxLag = 10 ;
checkMaxLag = @(x) validateattributes_with_return_value(x, {'numeric'}, {'positive', 'numel', 1}) ;

where validateattributes_with_return_value is a wrapper around Octave's validateattributes so that true or false is returned

function retval = validateattributes_with_return_value( varargin )
  try
    validateattributes( varargin{ : } ) ;
    retval = true ;
  catch
    retval = false ;
  end_try_catch
endfunction

then using either of

addRequired( parser , 'data' , @checkdata ) ;
addOptional( parser , 'maxLag' , defaultMaxLag , checkMaxLag ) ;

or 

addRequired( parser , 'data' , @checkdata ) ;
parser.addOptional( 'maxLag' , defaultMaxLag , checkMaxLag ) ;

where checkdata is a simple check that the input data is a numeric vector or matrix

function check = checkdata( x )
   check = false;
   if (~isnumeric(x))
       error('Input is not numeric');
   elseif (numel(x) <= 1)
       error('Input must be a vector or matrix');
   else
   check = true;
   end
endfunction

followed by

parse( parser , data , varargin{:} ) ;

fails with the error message

error: mdDelay: argument 'MAXLAG' is not a valid parameter

when called thus

tau = mdDelay( data , 'maxLag' , 25 ) ;

In this case the data is simply a 2000 row by 3 column matrix of numeric values.

I have tried changing the order the inputs appear in the code, thinking that it could be a problem with being "positional," but to no avail.

This is not a major concern as I now have functioning code using addParamValue, but maybe this highlights another known bug in Octave?

Upvotes: 0

Views: 183

Answers (1)

carandraug
carandraug

Reputation: 13091

You are using addOptional incorrectly. An optional parameter is an optional argument that is identified by its position on the list of arguments. So you should be calling it like so:

mdDelay (data, 25); # 25 is the value for maxLag

You are getting an error because your passing 'maxLag' (the string) as the value for maxLag (the option):

mdDelay (data, 'maxLag', 25); # 'maxLag' is the value for maxLag

And of course 'maxLag' fails the test:

checkMaxLag = @(x) validateattributes (x, {'numeric'}, {'positive', 'numel', 1}) ;
checkMaxLag('maxLag') # the string is not numeric

Upvotes: 1

Related Questions