 Overview of the Units Package - Maple Programming Help

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Overview of the Units Package

Basic Functionality

 • The Units package contains commands for unit conversion and provides environments for performing calculations with units.
 Using Units and Dimensions in Maple Documents provides an overview of using units and dimensions including how to:
 – Distinguish between environments
 – Perform conversions
 – Perform computations with units
 – Control the default system of units
 – Add new systems of units
 There is also an introductory tutorial on units and tolerances in the Maple Portal.  To access this tutorial, see Units Tutorial.
 • To perform quick unit conversions, use the Unit Converter point-and-click interface.
 • The Units package has two distinct sets of commands to customize the quantities available. The commands that manage the set of dimensions, units, and systems of units available in execution groups are listed below. The commands that manage the set of dimensions and units available in the Unit Converter dialog are listed in the Unit Converter Support Package page.
 • For additional information about the Units package, see the Details and Index pages or one of the following four worksheets that introduce the use of units in the various Maple environments:

 By default, loading the Units package enables the Simple Units Environment.

Accessing Units Package Commands

 • Each command in the Units package can be accessed by using either the long form or the short form of the command name in the command calling sequence.
 Long Form
 > Units[GetUnit]('light_year');
 Short Form
 > with(Units):
 > GetUnit('light_year');
 • If you load the Units package in order to use the short form of command names, be aware that this enables the Simple Units Environment by default. You can call the Units[UseMode] command beforehand to select a different units environment, or load another Units subpackage afterwards to override the environment. If you want to use the short form of Units commands, but not load any of the subpackages so that you stay in the default Units environment, you can load the Units[CommandsOnly] package.

List of Units Package Commands

 The following is a list of available commands.

 To display the help page for a particular Units package command, click the corresponding hyperlink.

Examples

To directly convert a single value from one unit to another, use the convert/units command.

 > $\mathrm{convert}\left(4.532,'\mathrm{units}',\frac{'N'}{{'m'}^{2}},\frac{'\mathrm{lb}''\mathrm{ft}'}{{'s'}^{2}{'\mathrm{ft}'}^{2}}\right)$
 ${3.045363395}$ (1)

To directly convert an absolute temperature to a different temperature scale, use the convert/temperature command. For temperature values, the convert/units command converts intervals.

 > $\mathrm{convert}\left(0,'\mathrm{units}','\mathrm{degC}','\mathrm{degF}'\right)$
 ${0}$ (2)
 > $\mathrm{convert}\left(0,'\mathrm{temperature}','\mathrm{degC}','\mathrm{degF}'\right)$
 ${32}$ (3)

Explore computations using units and systems in the Simple units environment.

Notes:

 – To enter a unit in 2-D Math input, select the unit from the appropriate Units palette. If the unit you want is not there, select $\mathrm{unit}$ and then enter the unit.
 – When you edit a unit, double brackets appear around it.
 > $\mathrm{with}\left(\mathrm{Units}\right):$
 Automatically loading the Units[Simple] subpackage
 > $\mathrm{UsingSystem}\left(\right)$
 ${\mathrm{SI}}$ (4)
 > $\mathrm{distance}≔3.53\mathrm{Unit}\left('\mathrm{ft}'\right)+4.1\mathrm{Unit}\left('m'\right)$
 ${\mathrm{distance}}{≔}{5.175944000}{}⟦{m}⟧$ (5)
 > $\mathrm{GetSystems}\left(\right)$
 ${\mathrm{Atomic}}{,}{\mathrm{CGS}}{,}{\mathrm{EMU}}{,}{\mathrm{ESU}}{,}{\mathrm{FPS}}{,}{\mathrm{MKS}}{,}{\mathrm{MTS}}{,}{\mathrm{SI}}$ (6)
 > $\mathrm{UseSystem}\left('\mathrm{FPS}'\right)$
 > $\mathrm{distance}≔3.53\mathrm{Unit}\left('\mathrm{ft}'\right)+4.1\mathrm{Unit}\left('m'\right)$
 ${\mathrm{distance}}{≔}{16.98144357}{}⟦{\mathrm{ft}}⟧$ (7)

For information on creating and managing systems, units, and dimensions, see the Units Package Commands page.

Compatibility

 • The Units package was updated in Maple 2018.