Math.units: Mathematical operations for units objects

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Math.unitsR Documentation

Mathematical operations for units objects


Mathematical operations for units objects


## S3 method for class 'units'
Math(x, ...)



object of class units


parameters passed on to the Math functions


Logarithms receive a special treatment by the underlying udunits2 library. If a natural logarithm is applied to some unit, the result is ln(re 1 unit), which means natural logarithm referenced to 1 unit. For base 2 and base 10 logarithms, the output lb(...) and lg(...) respectively instead of ln(...).

This is particularly important for some units that are typically expressed in a logarithmic scale (i.e., bels, or, more commonly, decibels), such as Watts or Volts. For some of these units, the default udunits2 database contains aliases: e.g., BW (bel-Watts) is an alias of lg(re 1 W); Bm (bel-milliWatts) is an alias of lg(re 0.001 W); BV is an alias of lg(re 1 V) (bel-Volts), and so on and so forth (see the output of valid_udunits() for further reference).

Additionally, the units package defines B, the bel, by default (because it is not defined by udunits2) as an alias of lg(re 1), unless a user-provided XML database already contains a definition of B, or the define_bel option is set to FALSE (see help(units_options)).


# roundings, cummulative functions
x <- set_units(sqrt(1:10), m/s)
signif(x, 2)

# trigonometry
sin(x) # not meaningful
x <- set_units(sqrt(1:10), rad)
x <- set_units(seq(0, 1, 0.1), 1)

# logarithms
x <- set_units(sqrt(1:10), W)
log(x) # base exp(1)
log(x, base = 3)
set_units(x, dBW) # decibel-watts
set_units(x, dBm) # decibel-milliwatts

units documentation built on Sept. 14, 2023, 1:06 a.m.