Numeric with units

[Fernando Perez]

John Hunter wrote:


> Has anyone written some code to integrate Numeric arrays with unum, or
> another units package?

Hi John,

take a look at ScientificPython's PhysicalQuantities.  It's not integrated with
Numeric, but it is a really solid units package.  You might be able to do the
integration with a bit of work.

Here's a simple example, with IPython's preprocessing of the input line to give
you a really convenient 'physics calculator'.  I wrote this to check student's
physics homework assignments quickly, and used it a lot:

[~]> ipython -p physics
Python 2.2.1 (#1, Aug 30 2002, 12:15:30)
Type "copyright", "credits" or "license" for more information.

IPython 0.2.15pre5 -- An enhanced Interactive Python.
?       -> Introduction to IPython's features.
@magic  -> Information about IPython's 'magic' @ functions.
help    -> Python's own help system.
object? -> Details about 'object'. ?object also works, ?? prints more.

IPython profile: physics

*** Simplified input for physical quantities enabled.
*** q is an alias for PhysicalQuantityInteractive
*** g = 9.8 m/s^2 has been defined
*** rad = pi/180  has been defined

In [1]: mass = 3.0 kg

In [2]: weight = mass*g

In [3]: weight
Out[3]: 29.4 m*kg/s^2

In [4]: weight.
weight._number        weight.cos            weight.sin            weight.unit
weight._sum           weight.inBaseUnits    weight.sqrt           weight.value
weight.b              weight.inUnitsOf      weight.tan
weight.convertToUnit  weight.isCompatible   weight.u

In [4]: weight.u('N')
Out[4]: 29.4 N