[SciPy-dev] Physical Constants

Chuck Harris Chuck.Harris at sdl.usu.edu
Thu Oct 3 16:21:27 CDT 2002

Hi All,

I had far too much time on my hands, so put all the CODATA physical constants
into a dictionary. I admit this doesn't save a whole lot of time over just
looking up the constants, but it does add some consistancy and self 
documention, i.e.

>>> import PhysicalConstants as pc
>>> c = pc.value('speed of light in vacuum')
>>> print c
>>> 299792458.0

The module documentation is

""" Fundamental Physical Constants

    These constants are taken from CODATA Recommended Values of the
    Fundamental Physical Constants: 1998. They may be found at
    physics.nist.gov/constants. The values are stored in the dictionary
    physical_constants as a tuple containing the value, the units, and
    the relative precision, in that order. All constants are in SI units
    unless otherwise stated.

    Several helper functions are provided:

    value(key) returns the value of the physical constant.
    unit(key) returns the units of the physical constant.
    precision(key) returns the relative precision of the physical constant.
    find(sub) prints out a list of keys containing the string sub. 

I've attached the python file for anyone who is interested.

On a further note, I have some small routines for generating
permutations, mixed radix counters, and grey code counters. I find
these come in handy on occasion. Any takers?


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