7/25/2019 Vl Argparse.m
1/3
function [opts, args] = vl_argparse(opts, args,
varargin)%VL_ARGPARSE Parse list of parameter-value pairs.% OPTS =
VL_ARGPARSE(OPTS, ARGS) updates the structure OPTS based on% the
specified parameter-value pairs ARGS={PAR1, VAL1, ... PARN,% VALN}.
If a parameter PAR cannot be matched to any of the fields% in OPTS,
the function generates an error.%% One or more of the (PAR, VAL)
pairs in the argument list can be% replaced by a structure; in this
case, the fields of the structure% are used as paramater names and
the field values as parameter% values.%% Parameters that have a
struct value in OPTS are processed% recursively, updating the
individual subfields. This behaviour% can be suppressed by using
VL_ARGPARSE(OPTS, ARGS,% 'nonrecursive'), in which case the struct
value is copied directly% (hence deleting any existing subfield
existing in OPTS). A direct% copy occurrs also if the struct value
in OPTS is a structure with% no fields.%% [OPTS, ARGS] =
VL_ARGPARSE(OPTS, ARGS) copies any parameter in% ARGS that does not
match OPTS back to ARGS instead of producing an% error. Options
specified as structures are passed back as a list% of (PAR, VAL)
pairs.
%% Example::% The function can be used to parse a list of
arguments% passed to a MATLAB functions:%% function
myFunction(x,y,z,varargin)% opts.parameterName = defaultValue ;%
opts = vl_argparse(opts, varargin)%% If only a subset of the
options should be parsed, for example% because the other options
are interpreted by a subroutine, then% use the form%
% [opts, varargin] = vl_argparse(opts, varargin)%% that copies
back to VARARGIN any unknown parameter.%% See also: VL_HELP().
% Copyright (C) 2015 Andrea Vedaldi.% Copyright (C) 2007-12
Andrea Vedaldi and Brian Fulkerson.% All rights reserved.%% This
file is part of the VLFeat library and is made available under% the
terms of the BSD license (see the COPYING file).
if ~isstruct(opts), error('OPTS must be a structure') ; endif
~iscell(args), args = {args} ; end
recursive = true ;if numel(varargin) == 1 if
strcmp(lower(varargin{1}), 'nonrecursive') ; recursive = false ;
else error('Unknown option specified.') ; end
7/25/2019 Vl Argparse.m
2/3
endif numel(varargin) > 1 error('There can be at most one
option.') ;end
% convert ARGS into a structureai = 1 ;params = {} ;values = {}
;while ai 0 % Process the struct value recursively if nargout >
1 [opts.(field), rest] = vl_argparse(opts.(field), values{i}) ;
args = horzcat(args, {field, cell2struct(rest(2:2:end),
rest(1:2:end),2)}) ; else opts.(field) = vl_argparse(opts.(field),
values{i}) ; end else % Copy the struct value as is
opts.(field) = values{i} ; end else % The parameter does not
have a struct value (in OPTS) % Copy as is opts.(field) = values{i}
; end else % The parameter was *not* found in OPTS if nargout
