function [ax,args,nargs] = axescheck(varargin)

% This function is undocumented and may change in a future release.

%AXESCHECK Process Axes objects from input list

%   [AX,ARGS,NARGS] = AXESCHECK(ARG1,ARG2,...) looks for Axes provided in

%   the input arguments. It first checks if ARG1 is an Axes. If so, it is

%   removed from the list in ARGS and the count in NARGS. AXESCHECK then

%   checks the arguments for Name, Value pairs with the name 'Parent'. If a

%   graphics object is found following the last occurance of 'Parent', then

%   all 'Parent', Value pairs are removed from the list in ARGS and the

%   count in NARGS. ARG1 (if it is an Axes), or the value following the

%   last occurance of 'Parent', is returned in AX. Double handles to

%   graphics objects are converted to graphics objects. If AX is determined

%   to be a handle to a deleted graphics object, an error is thrown.

%    Copyright 1984-2018 The MathWorks, Inc.

args = varargin; 

nargs = nargin; 

ax=[]; 

% Check for either a scalar numeric Axes handle, or any size array of Axes.

% 'isgraphics' will catch numeric graphics handles, but will not catch

% deleted graphics handles, so we need to check for both separately.

if (nargs > 0) && ... 

        ((isnumeric(args{1}) && isscalar(args{1}) && isgraphics(args{1}, 'axes')) ... 

        || isa(args{1},'matlab.graphics.axis.AbstractAxes') || isa(args{1},'matlab.ui.control.UIAxes')) 

  ax = handle(args{1});

  args = args(2:end);

  nargs = nargs-1;

end 

if nargs > 0 

  % Detect 'Parent' or "Parent" (case insensitive).

  inds = find(cellfun(@(x) (isStringScalar(x) || ischar(x)) && strcmpi('parent', x), args)); 

  if ~isempty(inds) 

    inds = unique([inds inds+1]);

    pind = inds(end);

    % Check for either a scalar numeric handle, or any size array of graphics objects.

    % If the argument is passed using the 'Parent' P/V pair, then we will

    % catch any graphics handle(s), and not just Axes.

    if nargs >= pind && ...

            ((isnumeric(args{pind}) && isscalar(args{pind}) && isgraphics(args{pind})) ...

            || isa(args{pind},'matlab.graphics.Graphics'))

      ax = handle(args{pind});

      args(inds) = [];

      nargs = length(args);

    end

  end 

end 

% Make sure that the graphics handle found is a scalar handle, and not an

% empty graphics array or non-scalar graphics array.

if (nargs < nargin) && ~isscalar(ax) 

    throwAsCaller(MException(message('MATLAB:graphics:axescheck:NonScalarHandle')));

end 

% Throw an error if a deleted graphics handle is detected.

if ~isempty(ax) && ~isvalid(ax) 

  % It is possible for a non-Axes graphics object to get through the code

  % above if passed as a Name/Value pair. Throw a different error message

  % for Axes vs. other graphics objects.

  if(isa(ax,'matlab.graphics.axis.AbstractAxes') || isa(ax,'matlab.ui.control.UIAxes'))

    throwAsCaller(MException(message('MATLAB:graphics:axescheck:DeletedAxes')));

  else

    throwAsCaller(MException(message('MATLAB:graphics:axescheck:DeletedObject')));

  end

end