Frequency has the dimension inverse time. The SI unit of frequency is the hertz, which is defined as an inverse second.

Maple knows the units of frequency listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, hertz[SI] or f[standard]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, hertz or f.

In some cases, it is desirable to represent hertz as revolutions per second.  The default hertz can be changed to this new definition using the command Units:-AddUnit('hertz', 'context'='SI', 'conversion'=2*Pi*'rad'/'s', 'check'=false).

The units of frequency are defined as follows.

A hertz is defined as 1 per second.

A fresnel is defined as $1.\times {10}^{12}$ hertz.

A planck frequency is defined as 1 per planck time.

$\mathrm{convert}\left('\mathrm{Hz}'\,'\mathrm{dimensions}'\,'\mathrm{base}'=\mathrm{true}\right)$

$\frac{1}{\mathrm{time}}$

$\mathrm{convert}\left(13.258\,'\mathrm{units}'\,'\mathrm{Hz}'\,'\mathrm{fresnel}'\right)$

$1.325800000\times {10}^{\mathrm{-11}}$

$\mathrm{Units}:-\mathrm{AddUnit}\left('\mathrm{hertz}'\,'\mathrm{context}'='\mathrm{SI}'\,'\mathrm{conversion}'=\frac{2\mathrm{\pi }'\mathrm{rad}'}{'s'}\,'\mathrm{check}'=\mathrm{false}\right)$

$\mathrm{convert}\left(52.25\,'\mathrm{units}'\,'\mathrm{Hz}'\,\frac{'\mathrm{deg}'}{'s'}\right)$

$18810.00$