Mathematica 9 is now available

Wolfram Library Archive


All Collections Articles Books Conference Proceedings
Courseware Demos MathSource Technical Notes
Title Downloads

Functions EvaluateAt, EvaluateAtPattern, PositionMin, PositionMax, Cases, Select, Position
Author

Ted Ersek
Organization: Naval Air Warfare Center, Aircraft Division
URL: http://www.verbeia.com/mathematica/
Old MathSource #

0211-532
Revision date

2004-05-14
Description

The conventions for specifying sequences and levels are documented in sections A.3.5 and A.3.6 respectively in The Mathematica Book. In those sections the documentation explains how negative integers are used in sequence and level specifications. However the built in versions of Cases, Select, Position, StringPosition do not allow use of negative integers for sequence or level specification. This package enhances those functions to ensure they treat negative numbers as described in section A.3.5 and A.3.6.

The package also defines new functions PositionMin, PositionMax, EvaluateAt, EvaluateAtPattern. In addition the package enhances Position so it can return 'extended positions' which are needed to give the position of (a+c) in f[1+a+b+c]. The functions MapAt, ReplacePart, Extract and EvaluateAt can work with extended positions. For an explanation of installing the package and demonstration of all enhancements see the notebook (SelectingElementsExamples.nb).
Subject

*Mathematica Technology > Programming
Keywords

Element, Evaluate, Evaluation, Min, Max, String, Cases, Select, Position
Downloads Download Wolfram CDF Player

Download
SelectingElements.m (21.9 KB) - Mathematica package [for Mathematica 5.0]
Download
SelectingElementsTutorial.nb (41.4 KB) - Mathematica notebook [for Mathematica 5.0]