units

Zsh script to convert a real number from one unit to another

Installation / uninstallation

The following additional variables are supported:

• DESTDIR -- determines environment for staged installs,
• BINDIR -- determines where the script will be installed (default: /usr/local/bin).

To install, just run make with superuser privileges.
To uninstall, just run make uninstall with the same privileges.

To change the value of any make variables, run, e.g., make FOO=bar install

Requirements

The script requires the following to run:

• zsh

The provided Makefile assumes a linux operating system.

Usage

units

    Converts a real number from one unit to another

    usage: units  [operation] NUM FROM TO
        NUM:  a number
        FROM: units of NUM
        TO:   units to which we want to convert NUM

    operations:
        -h               Show this message.

    Valid conversion units:

        [mass]

            lb         :: pounds
            kg         :: kilograms

        [energy]

            hartree    :: Hartree atomic units (au)
            rydberg    :: Rydberg
            eV         :: electron volts
            J          :: Joules
            C          :: Celcius (E=kT)
            K          :: Kelving (E=kT)
            invcm      :: Wavenumbers (cm^-1)
            Hz         :: Hertz (frequency)

        [distance]

            ym         :: yoctometers (1e-24 m)
            zm         :: zeptometers (1e-21 m)
            am         :: attometers  (1e-18 m)
            fm         :: femtometers (1e-15 m)
            pm         :: picometers  (1e-12 m)
            nm         :: nanometers  (1e-9  m)
            μm         :: micrometers (1e-6  m)
            mm         :: millimeters (1e-3  m)
            cm         :: centimeters (1e-2  m)
            dm         :: decimeters  (1e-1  m)
            m          :: meters
            km         :: kilometers  (1e+3  m)

            ft         :: feet
            mi         :: miles
            in         :: inches

        [time]
            s          :: seconds
            ys         :: yoctoseconds (1e-24    s)
            zs         :: zeptoseconds (1e-21    s)
            as         :: attoseconds  (1e-18    s)
            fs         :: femtoseconds (1e-15    s)
            ps         :: picoseconds  (1e-12    s)
            ns         :: nanoseconds  (1e-9     s)
            μs         :: microseconds (1e-6     s)
            ms         :: milliseconds (1e-3     s)
            cs         :: centiseconds (1e-2     s)
            ds         :: deciseconds  (1e-1     s)
            ks         :: kiloseconds  (1e+3     s)
            plancktime :: planck time  (5.39e-44 s)
            min        :: minutes
            h          :: hours
            d          :: days
            y          :: years

        Note: Distance and energy can be related to each other through the relation

            c = λ*ν,

        where λ is a wavelength (meters), ν is a frequency (Hz), and c is the speed of
        light in a vacuum (299792458 m/s) which means the following is a valid implementation
        of units :

            units 1 ev μm