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 and plctime.
scale
(PLFLT, 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, 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, input)
See documentation of offset1.
ccontrol
(PLINT, 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, 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, input)
Year of epoch.
month
(PLINT, input)
Month of epoch in range from 0 (January) to 11 (December).
day
(PLINT, input)
Day of epoch in range from 1 to 31.
hour
(PLINT, input)
Hour of epoch in range from 0 to 23
min
(PLINT, input)
Minute of epoch in range from 0 to 59.
sec
(PLFLT, input)
Second of epoch in range from 0. to 60.
Redacted form:
General: plconfigtime(scale, offset1, offset2, ccontrol, ifbtime_offset, year, month, day, hour, min, sec)
This function is used in example 29.