das2/units.h File Reference

Defines units used for items in the stream, most notably time units that reference an epoch and a step size. More...

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Detailed Description

Defines units used for items in the stream, most notably time units that reference an epoch and a step size.

#include <stdbool.h>

Go to the source code of this file.

Defines
#define	FILL_VALUE   -1e31
	Canonical fill value.
Typedefs
typedef const char *	UnitType
	Enumeration of unit types, that correspond to physical unit types.

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Typedef Documentation

typedef const char* UnitType

Enumeration of unit types, that correspond to physical unit types.

Note that although these are strings, getUnitsFromString should be be used to get a reference to the enumerated string since pointer comparison is done in the code.

The Epoch Time unit types understood by this library are:

• UNIT_US2000 - Microseconds since midnight, January 1st 2000
• UNIT_MJ1958 - Days since midnight January 1st 1958
• UNIT_T2000 - Seconds since midnight, January 1st 2000
• UNIT_T1970 - Seconds since midnight, January 1st 1970
• UNIT_UTC - Time strings on the gregorian calendar

As it stands the library currently does not understand SI prefixes, so each scaled unit has it's own entry. This should change.

• UNIT_SECONDS - Seconds, a time span.
• UNIT_HOURS - hours, a time span = 3600 seconds.
• UNIT_MIRCOSECONDS - A smaller time span.
• UNIT_HERTZ - Hertz, a measure of frequency.
• UNIT_KILO_HERTZ - KiloHertz, another measure of frequency.
• UNIT_E_SPECDENS - Electric Spectral Density, V**2 m**-2 Hz**-1;
• UNIT_B_SPECDENS - Magnetic Spectral Density, nT**2 Hz**-1;
• UNIT_NT - Magnetic Field intensity, nT
• UNIT_NUMBER_DENS - Number density, the number of items in a cubic centimeter
• UNIT_DB - Decibels, a ratio measure, typically versus 1.0.
• UNIT_KM - Kilometers, a unit of distance
• UNIT_DEGREES - Degrees, a ratio measure on circles: (arch length / circumferance) * 360

And if you don't know what else to use, try this:

• UNIT_DIMENSIONLESS - I.E. No units

Todo:

Redo units as small structures