Values

Physical data values, including time, and thier units. More...

Data Structures
struct	das_datum
	An atomic data processing unit, and it's units. More...
struct	das_time
	Basic date-time structure used throughout the Das1 & Das2 utilities. More...

Typedefs
typedef const char *	das_units
	Handle SI and other units, with accommodations for Epoch systems, from units.h. More...

Enumerations
enum	das_val_type {   vtUnknown = 0 , vtUByte = 1 , vtByte = 2 , vtUShort = 3 ,   vtShort = 4 , vtUInt = 5 , vtInt = 6 , vtULong = 7 ,   vtLong = 8 , vtFloat = 9 , vtDouble = 10 , vtTime = 11 ,   vtIndex = 12 , vtText = 13 , vtGeoVec = 14 , vtByteSeq = 15 }
	Enumeration of types stored in Das Array (DasAry) objects from value.h. More...

Detailed Description

Physical data values, including time, and thier units.

Typedef Documentation

das_units

typedef const char* das_units

Handle SI and other units, with accommodations for Epoch systems, from units.h.

Note that although these are strings, Units_fromStr() should be be used to get a reference to the enumerated string since pointer equality comparison is done in the code. Thus UnitType objects created using the functions in this module satisfy the rule:

das_unit a;
das_unit b;
 
if(a == b){
  // Units are equal
}

The Epoch Time unit types understood by this library are:

• UNIT_US2000 - Non-Leap microseconds since midnight, January 1st 2000
• UNIT_MJ1958 - Days since midnight January 1st 1958
• UNIT_T2000 - Non-Leap seconds since midnight, January 1st 2000
• UNIT_T1970 - Non-Leap seconds since midnight, January 1st 1970
• UNIT_UTC - Time strings on the gregorian calendar
• UNIT_NS2020 - Non-Leap nanoseconds since midnight Jan 1st, 2020, typically transmitted as signed 8-byte integers

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 / circumference) * 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

Enumeration Type Documentation

das_val_type

enum das_val_type

Enumeration of types stored in Das Array (DasAry) objects from value.h.

Note that any kind of value may be stored in a Das Array, but most of these types have runtime type safty checks.

See also

value.h for a list of functions for worknig with the the das_val_type enumeration

Enumerator
vtUnknown	For generic storage, designates elements as unknown, you have to cast the array return values yourself.
vtUByte	The basic types. Indicates array values are unsigned 8-bit integers (bytes)
vtByte	Indicates array values are signed 8-bit integers (signed bytes)
vtUShort	Indicates array values are unsigned 16-bit integers (shorts)
vtShort	Indicates array values are signed 16-bit integers (shorts)
vtUInt	Indicates array values are unsigned 32-bit integers (uints)
vtInt	Indicates array values are signed 32-bit integers (ints)
vtULong	Indicates array values are unsigned 64-bit unsigned integers (ulongs)
vtLong	Indicates array values are unsigned 64-bit integers (longs)
vtFloat	Indicates array values are 32-bit floating point values (floats)
vtDouble	Indicates array values are 64-bit floating point values (doubles)
vtTime	Indicates array values are das_time_t structures.
vtText	Indicates datum values are const char* pointers to null terminated UTF-8 strings.
vtGeoVec	Value are a vector struct as defined by vector.h.
vtByteSeq	Indicates values are size_t plus const ubyte* pairs, no more is known about the bytes.