====== root.Document ======

===== Motivation =====
The reason why I wanted this method is to have an additional interface to access already loaded documents (from within scripts) without being given there handles. The method closely works together with the [[root.Documents]] method--please also read this page...

===== Method reference ('root.Help('Document')') =====
<file> ROOT::Document  - get one "Document" (VB-Style interface)
 
 FORMAT:       object = xff.Document(dspec);
 
 Input fields:
 
       dspec       either numbered object or (partial) filename
 
 Output fields:
 
       object      found object (otherwise: error)</file>

===== Examples =====
If you already know that an object by the name ''SB5318_ISO_SAG.vmr'' is loaded, the following syntax gives you the object handle:

<code matlab xff_root_document_ex1.m>% get root object handle
root = xff;

% access document
vmr = root.Document('SB5318_ISO_SAG.vmr');</code>

Naturally, in scripts you would rather look this information up:

<code matlab xff_root_document_ex2.m>% get root object handle
root = xff;

% get all documents
docs = root.Documents;

% iterate until found
colin_brain = [];
for dc = 1:numel(docs)
    if ischar(docs{dc}) && ...
       ~isempty(regexpi(docs{dc}, 'colin_brain'))
        colin_brain = root.Document(docs{dc});
        break;
    end
end

% load anyway
if isempty(colin_brain)
    colin_brain = neuroelf_file('c', 'colin_brain.vmr');
end</code>