State of the Units Package



Well, mainly so I know what I still need to do, here is a summary of
where things are and where I'd like to take them, as of 0.50:

Currently:

Basic functionality, including grouping over the + operator, is
complete
and seems to be working.  setunits, forget, convert, and several other
functions have passed rather limited testing.

Limited definitions are present for most dimensions which will be
initially supported.  This is easily extended, and will in fact be one
of the last things done.

Initial support for maxima-init.mac definition of default units is in
place.  Other user settings are not yet responsive to maxima-init
overrides.

texinfo documentation has been started, but is currently rather
minimal.

limited dimensional analysis abilities are present, but are nowhere
near as powerful as dimension.mac.

A few other misc. things are partially in place.

Todo:

I have looked over some examples and documentation for Maple and
Mathematica unit pacakges:
http://www.adeptscience.co.uk/products/mathsim/maple/apps/subcategory/106/Dimensional-Analysis/Engineering/category106.html
http://stanheckman.com/a/99h/lightgale/html/PhysicalUnits.html

Combining ideas from those packages with things I already knew I needed
to do, here is a rough todo list:

- mactex support for unit characters, and unit output in general
- complete dimensional analysis support
- temperature support - both absolute and non-absolute
- complete awareness of maxima-init.mac setting overrides
- addunits command (unitinfo is probably not useful as originally 
  envisioned) will need to both intelligently handle metric and 
  non-metric additons to exhisting dimensions, as well as totally 
  new dimensions with associated units.
- display of units/dimensions associated with variables
- intelligent plotting - axis labels of unit quantities, arguments 
  to x and y limits in units handled intelligently
- command to show current unit "environment" - i.e. what dimensions 
  are being used and what units are associated with those dimensions
- lists of quantities with dimension - uniform dimension lists and 
  non-uniform dimension both.  Make decision about how to impliment 
  factor over list command from Mathematica package (FactorUnits)
- display in abbreviations or whole words as user option, and also 
  Mathematica mode of fullname with one or two dimensions, 
  abbreviations with more
- Address units for the following functions (thanks Stan Heckman  
  Mathematica package):
    Min and Max
    Inequalities
    Matricies and Vectors (possible - will need to consider issues)
    perhaps solve?
    any Maxima specific functionality which would be impacted
- in physconst package, make sure functions use numerical value of 
  constant for inequality comparisions with other quantities of same
  dimension
- Set user default units by mks, cgs, other options
- dig up old code to prevent user from assigning values to 
  variable names, and impliment it
- check dimensional consistency of expression before performing
  evaluation - at user option?

Other features will undoubtedly suggest themselves as I go.

I also need to figure out if I'm working on the lisp side of things in
the best available way, or if I should be working on displa instead.

Cheers,
CY


		
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