MathGroup Archive 2013

[Date Index] [Thread Index] [Author Index]

Search the Archive

ExtendUnits package still works with old symbolic units

  • To: mathgroup at
  • Subject: [mg131718] ExtendUnits package still works with old symbolic units
  • From: "djmpark" <djmpark at>
  • Date: Mon, 23 Sep 2013 21:59:10 -0400 (EDT)
  • Delivered-to:
  • Delivered-to:
  • Delivered-to:
  • Delivered-to:

The new units facilities of Mathematica Version 9 has advantages and
disadvantages. It uses Strings instead of symbols, often requires an online
connection and encourages the mixture of units into equations and various
expressions where they might be less than appropriate.


It is my view that units are part of the data and should only come into play
after symbolic manipulation has been performed, that is by substitution at
the end of a derivation.


In any case, if you prefer the older units style the ExtendUnits package,
which I sell for $30 from links at my web site, retains the old units and
has many useful features.


1) The old Unit and PhysicalConstants units have been built-in so will still
be available.

2) There is a procedure for generating expressions that have whatever
implied input and output units that may be desired. These could then be used
in numerical routines without having to carry explicit units in expressions.

3) Custom units can be installed so you can use all the variations desired.

4) Reduced units where some physical constants are specified to be 1 can be

5) Decibel units can be used.

6) Units can be parsed into descending compatible units, e.g., Hours,
Minutes, Seconds, or simultaneously converted to multiple compatible units.

7) There is a handy palette that gives a quick listing of built-in units
(both alphabetically and by magnitude) and constants as well as the routines
in the package,



David Park

djmpark at 

  • Prev by Date: Re: list mutability (very basic question)
  • Next by Date: Third order ODE not working
  • Previous by thread: Re: Data set association, returning values
  • Next by thread: Third order ODE not working