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UDUNITS Introduction and Use
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The Unidata units library, UDUNITS, supports conversion of unit specifications between formatted and binary forms, arithmetic manipulation of unit specifications, and conversion of values between compatible scales of measurement.
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A unit is the amount by which a physical quantity is measured. For example:
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Physical Quantity
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Possible Unit
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time
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weeks
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distance
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centimeters
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power
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watts
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The UDUNITS package also contains an interactive utility,
udunits, which has two modes.
In one mode, both an input and output unit specification are given, causing the utility to print the conversion between them:
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You have: inch
You want: cm
cm = inch*2.54
cm = inch/0.393701
You have: (15 lbs force/in)^2
You want: atm2
atm2 = (15 lbs force/in)^2*0.995719
atm2 = (15 lbs force/in)^2/1.0043
You have: celsius
You want: fahrenheit
fahrenheit = celsius*1.8 + 32
fahrenheit = celsius/0.555556 + 32
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In the other mode, only an input unit specification is given. This causes the utility to print the definition -- in standard units -- of the input unit:
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You have: fahrenheit
You want:
Definition: "0.555556 kelvin @ 255.372"
You have: geopotential meters
You want:
Definition: "9.80665 meter2 second-2"
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Further information on this package can be found in the C manual page or FORTRAN manual page, the associated utility manual page, or the perl extension manual page.
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