You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: arrow3d.m
    path of file: ./repos/mtex/geometry/@vector3d
    
    the code of the file until where you have to start completion: function h = arrow3d(vec,varargin)
% plot three dimensional arrows
%
% Syntax
%   arrow3d(v)
%   arrow3d(v,'arrowWidth',0.05)
%
% Input
%  v - @vector3d
%
% See also
% savefigure vector3d/scatter3 vector3d/plot3 vector3d/text3

% where to plot

    
function h = arrow3d(vec,varargin)
% plot three dimensional arrows
%
% Syntax
%   arrow3d(v)
%   arrow3d(v,'arrowWidth',0.05)
%
% Input
%  v - @vector3d
%
% See also
% savefigure vector3d/scatter3 vector3d/plot3 vector3d/text3

% where to plot
if check_option(varargin,'parent')
  ax = get_option(varargin,'parent');
else
  ax = gca;
end