The module "elem" of the Mastrave modelling library


Daniele de Rigo


Copyright and license notice of the function elem



Copyright © 2005,2006,2007,2008,2009,2010,2011,2012 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

Function declaration



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




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:

   temporary variables, indices

Version: 0.5.2




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

This page is licensed under a Creative Commons Attribution-NoDerivs 3.0 Italy License.

This document is also part of the book:
de Rigo, D. (2012). Semantic Array Programming with Mastrave - Introduction to Semantic Computational Modelling.

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