plconfigtime - Configure the transformation between
continuous and broken-down time for the current stream
plconfigtime(scale, offset1, offset2,
ccontrol, ifbtime_offset, year, month,
day, hour, min, sec)
Configure the transformation between continuous and broken-down
time for the current stream. This transformation is used by both
plbtime(3plplot) and plctime(3plplot).
Redacted form: General: plconfigtime(scale, offset1, offset2,
ccontrol, ifbtime_offset, year, month, day, hour, min, sec)
This function is used in example 29.
- scale
(PLFLT(3plplot), input)
- The number of days per continuous time unit. As a special case, if
scale is 0., then all other arguments are ignored, and the result
(the default used by PLplot) is the equivalent of a call to
plconfigtime(1./86400., 0., 0., 0x0, 1, 1970, 0, 1, 0, 0, 0.). That is,
for this special case broken-down time is calculated with the proleptic
Gregorian calendar with no leap seconds inserted, and the continuous time
is defined as the number of seconds since the Unix epoch of
1970-01-01T00:00:00Z.
- offset1
(PLFLT(3plplot), input)
- If ifbtime_offset is true, the parameters offset1 and
offset2 are completely ignored. Otherwise, the sum of these
parameters (with units in days) specify the epoch of the continuous time
relative to the MJD epoch corresponding to the Gregorian calendar date of
1858-11-17T00:00:00Z or JD = 2400000.5. Two PLFLT numbers are used to
specify the origin to allow users (by specifying offset1 as an
integer that can be exactly represented by a floating-point variable and
specifying offset2 as a number in the range from 0. to 1) the
chance to minimize the numerical errors of the continuous time
representation.
- offset2
(PLFLT(3plplot), input)
- See documentation of offset1.
- ccontrol
(PLINT(3plplot), input)
- ccontrol contains bits controlling the transformation. If the 0x1
bit is set, then the proleptic Julian calendar is used for broken-down
time rather than the proleptic Gregorian calendar. If the 0x2 bit is set,
then leap seconds that have been historically used to define UTC are
inserted into the broken-down time. Other possibilities for additional
control bits for ccontrol exist such as making the historical time
corrections in the broken-down time corresponding to ET (ephemeris time)
or making the (slightly non-constant) corrections from international
atomic time (TAI) to what astronomers define as terrestrial time (TT). But
those additional possibilities have not been implemented yet in the
qsastime library (one of the PLplot utility libraries).
- ifbtime_offset
(PLBOOL(3plplot), input)
- ifbtime_offset controls how the epoch of the continuous time scale
is specified by the user. If ifbtime_offset is false, then
offset1 and offset2 are used to specify the epoch, and the
following broken-down time parameters are completely ignored. If
ifbtime_offset is true, then offset1 and offset2 are
completely ignored, and the following broken-down time parameters are used
to specify the epoch.
- year
(PLINT(3plplot), input)
- Year of epoch.
- month
(PLINT(3plplot), input)
- Month of epoch in range from 0 (January) to 11 (December).
- day
(PLINT(3plplot), input)
- Day of epoch in range from 1 to 31.
- hour
(PLINT(3plplot), input)
- Hour of epoch in range from 0 to 23
- min
(PLINT(3plplot), input)
- Minute of epoch in range from 0 to 59.
- sec
(PLFLT(3plplot), input)
- Second of epoch in range from 0. to 60.
Many developers (who are credited at
http://plplot.org/credits.php) have contributed to PLplot over its long
history.
PLplot documentation at http://plplot.org/documentation.php.