## The module "elem" of the Mastrave modelling library

Daniele de Rigo

The file elem.m is part of Mastrave.

Mastrave is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Mastrave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Mastrave. If not, see http://www.gnu.org/licenses/.

#### Function declaration

elements = elem( values      ,
rows        ,
cols   = -1 ,
...         )



#### Description

Utility function for enabling on the fly elements' extraction, even from a temporary variable that is unnamed and whose lifetime ends after the evaluation of the command which created it. A subset of elements of such a temporary variable cannot be explicitly and portably accessed without assigning the temporary variable to another explicit variable or passing it to a function. This utility function works around the issue while also providing advanced methods for indexing (even multiple arrays at the same time).

#### Input arguments


values          ::cellnumstring::
Array of objects.

rows            ::cellindex::
Scalar, vector or matrix of row indices, or cell-array
whose elements are scalar, vectors or matrices of row
indices (row subscripts).

cols            ::index,string::
Scalar, vector or matrix of column indices, or ascii flag
indicating the dimension along which the  rows  indices
have to be considered.
A cell-array whose elements are all either column indices
or dimensions, is also supported.
Valid options for the ascii flags are:

Option   │    Meaning
────────────┼──────────────────────────────
'r'      │  Rows (equivalent to -1).
────────────┼──────────────────────────────
'c'      │  Columns (equivalent to -2).

Output arguments:
elements        ::generic::



#### Example of usage

See also:
mfind

Keywords:
temporary variables, indices

Version: 0.5.2

#### Support

The Mastrave modelling library is committed to provide reusable and general - but also robust and scalable - modules for research modellers dealing with computational science.  You can help the Mastrave project by providing feedbacks on unexpected behaviours of this module.  Despite all efforts, all of us - either developers or users - (should) know that errors are unavoidable.  However, the free software paradigm successfully highlights that scientific knowledge freedom also implies an impressive opportunity for collectively evolve the tools and ideas upon which our daily work is based.  Reporting a problem that you found using Mastrave may help the developer team to find a possible bug.  Please, be aware that Mastrave is entirely based on voluntary efforts: in order for your help to be as effective as possible, please read carefully the section on reporting problems.  Thank you for your collaboration.

Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Daniele de Rigo