hplgit / physical-quantities

The PhysicalQuantity class made independent of K. Hinsen's ScientificPython package.

physical-quantities

The PhysicalQuantity class made independent of K. Hinsen's ScientificPython package. This class is very useful for computation involving numbers with units.

Demo

    >>> from PhysicalQuantities import PhysicalQuantity as p  # short hand
    >>> distance1 = p('10 m')
    >>> distance2 = p('10 km')
    >>> total = distance1 + distance2
    >>> total
    PhysicalQuantity(10010.0,'m')
    >>> total.convertToUnit('km')
    >>> total.getValue()
    10.01
    >>> total.getUnitName()
    'km'
    >>> total = total.inBaseUnits()
    >>> total
    PhysicalQuantity(10010.0,'m')
    >>>
    >>> t = p(314159., 's')
    >>> # convert to days, hours, minutes, and second:
    >>> t2 = t.inUnitsOf('d','h','min','s')
    >>> t2_print = ' '.join([str(i) for i in t2])
    >>> t2_print
    '3.0 d 15.0 h 15.0 min 59.0 s'
    >>>
    >>> e = p('2.7 Hartree*Nav')
    >>> e.convertToUnit('kcal/mol')
    >>> e
    PhysicalQuantity(1694.2757596034764,'kcal/mol')
    >>> e = e.inBaseUnits()
    >>> str(e)
    '7088849.77818 kg*m**2/s**2/mol'
    >>>
    >>> freeze = p('0 degC')
    >>> freeze = freeze.inUnitsOf ('degF')
    >>> str(freeze)
    '32.0 degF'
    >>>

Run

pydoc PhysicalQuantities

to see an overview of all the physical units and their notation supported by the PhysicalQuantities module.

Installation

sudo pip install  -e git+https://github.com/hplgit/physical-quantities.git#egg=physical-quantities

Or

git clone https://github.com/hplgit/physical-quantities.git
cd physical-quantities
sudo python setup.py install

Note

The PhysicalQuantities module was developed by Dr. Konrad Hinsen and appears in the ScientificPython package. Unfortunately, ScientificPython requires NumPy version 1.8 or less, and that is why H. P. Langtangen made this PhysicalQuantities module independent of the ScientificPython package such that it is easy in any project to compute with units.

Python 3 version

The PhysicalQuantities.py file in the present directory is for Python 2. There is an experimental Python 3 version in the subdirectory py23, which depends on the future package.