Units
The two main functions for working with units are uparse and u_str:
DynamicQuantities.UnitsParse.@u_str — Macrou"[unit expression]"Parse a string containing an expression of units and return the corresponding Quantity object with Float64 value. For example, u"km/s^2" would be parsed to Quantity(1000.0, length=1, time=-2).
Note that inside this expression, you also have access to the Constants module. So, for example, u"Constants.c^2 * Hz^2" would evaluate to the quantity corresponding to the speed of light multiplied by Hertz, squared.
DynamicQuantities.UnitsParse.uparse — Functionuparse(s::AbstractString)Parse a string containing an expression of units and return the corresponding Quantity object with Float64 value. For example, uparse("m/s") would be parsed to Quantity(1.0, length=1, time=-1).
Note that inside this expression, you also have access to the Constants module. So, for example, uparse("Constants.c^2 * Hz^2") would evaluate to the quantity corresponding to the speed of light multiplied by Hertz, squared.
Available units
The base SI units are as follows. You can either use the @u_str macro like 1.5u"m", or simply import these explicitly from the package with using DynamicQuantities: m.
DynamicQuantities.Units.m — ConstantLength in meters. Available variants: fm, pm, nm, μm (/um), cm, inch, dm, mm, ft, km, mi, Mm, Gm.
DynamicQuantities.Units.kg — ConstantMass in kilograms. Available variants: pg, ng, μg (/ug), mg, g.
DynamicQuantities.Units.s — ConstantTime in seconds. Available variants: fs, ps, ns, μs (/us), ms, min (/minute), h (/hr), day (/d), wk, yr, kyr, Myr, Gyr.
DynamicQuantities.Units.A — ConstantCurrent in Amperes. Available variants: nA, μA (/uA), mA, kA.
DynamicQuantities.Units.K — ConstantTemperature in Kelvin. Available variant: mK.
DynamicQuantities.Units.cd — ConstantLuminosity in candela. Available variant: mcd.
DynamicQuantities.Units.mol — ConstantAmount in moles. Available variant: pmol, nmol, μmol (/umol), mmol.
Derived units
Several derived SI units are available as well:
DynamicQuantities.Units.C — ConstantCharge in Coulombs.
DynamicQuantities.Units.F — ConstantCapacitance in Farads. Available variants: fF, pF, nF, μF (/uF), mF.
DynamicQuantities.Units.H — ConstantElectrical inductance in henries.
DynamicQuantities.Units.Hz — ConstantFrequency in Hertz. Available variants: nHz, μHz (/uHz), mHz, kHz, MHz, GHz.
DynamicQuantities.Units.J — ConstantEnergy in Joules. Available variant: kJ.
DynamicQuantities.Units.L — ConstantVolume in liters. Available variants: μL (/uL), mL, cL, dL.
DynamicQuantities.Units.M — ConstantMolar concentration in molar. Available variants: pM, nM, μM (/uM), mM.
DynamicQuantities.Units.N — ConstantForce in Newtons. Available variants: μN (/uN), mN, kN.
DynamicQuantities.Units.Pa — ConstantPressure in Pascals. Available variant: kPa.
DynamicQuantities.Units.S — ConstantElectrical conductance, electric susceptance, and electric admittance in siemens. Available variants: nS, μS (/uS), mS, kS, MS, GS.
DynamicQuantities.Units.T — ConstantMagnetic flux density in Teslas. Available variants: Gauss
DynamicQuantities.Units.V — ConstantVoltage in Volts. Available variants: pV, nV, μV (/uV), mV, kV,MV,GV`.
DynamicQuantities.Units.W — ConstantPower in Watts. Available variants: mW, kW, MW, GW.
DynamicQuantities.Units.Wb — ConstantMagnetic flux in webers. Available variants: nWb, μWb (/uWb), mWb.
DynamicQuantities.Units.bar — ConstantPressure in bars. Available variants: mbar.
DynamicQuantities.Units.rad — ConstantAngle in radians. Note that the SI definition is simply 1 rad = 1, so use symbolic units to avoid this. Available variants: nrad, μrad (/urad), mrad, deg, arcmin, arcsec, μarcsec (/uarcsec), marcsec.
DynamicQuantities.Units.sr — ConstantSolid angle in steradians. Note that the SI definition is simply 1 sr = 1, so use symbolic units to avoid this.
DynamicQuantities.Units.Ω — ConstantResistance in Ohms. Available variant: nΩ, μΩ (/uΩ), mΩ, kΩ, MΩ, GΩ. Also available is ASCII ohm (with variants nohm, μohm (/uohm), mohm, kohm, Mohm, Gohm).
Custom Units
You can define custom units with the @register_unit macro:
DynamicQuantities.@register_unit — Macro@register_unit symbol valueRegister a new unit under the given symbol to have a particular value.
Example
julia> @register_unit MyVolt 1.5u"V"This will register a new unit MyVolt with a value of 1.5u"V". You can then use this unit in your calculations:
julia> x = 20us"MyVolt^2"
20.0 MyVolt²
julia> y = 2.5us"A"
2.5 A
julia> x * y^2 |> us"W^2"
281.25 W²
julia> x * y^2 |> us"W^2" |> sqrt |> uexpand
16.77050983124842 m² kg s⁻³