next up previous
Next: SLA_CLDJ - Calendar to MJD
Up: SUBPROGRAM SPECIFICATIONS
Previous: SLA_CC62S - Cartesian 6-Vector to Spherical

SLA_CD2TF - Days to Hour,Min,Sec   

ACTION:
Convert an interval in days to hours, minutes, seconds (single precision).

CALL:
CALL sla_CD2TF (NDP, DAYS, SIGN, IHMSF)

GIVEN:

NDP I number of decimal places of seconds
DAYS R interval in days

RETURNED:

SIGN C `+' or `-'
IHMSF I(4) hours, minutes, seconds, fraction

NOTES:
1.
NDP less than zero is interpreted as zero.
2.
The largest useful value for NDP is determined by the size of DAYS, the format of REAL floating-point numbers on the target machine, and the risk of overflowing IHMSF(4). For example, on a VAX computer, for DAYS up to 1.0, the available floating-point precision corresponds roughly to NDP=3. This is well below the ultimate limit of NDP=9 set by the capacity of the 32-bit integer IHMSF(4).
3.
The absolute value of DAYS may exceed 1.0. In cases where it does not, it is up to the caller to test for and handle the case where DAYS is very nearly 1.0 and rounds up to 24 hours, by testing for IHMSF(1)=24 and setting IHMSF(1-4) to zero.


next up previous
Next: SLA_CLDJ - Calendar to MJD
Up: SUBPROGRAM SPECIFICATIONS
Previous: SLA_CC62S - Cartesian 6-Vector to Spherical

SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
12 October 1999
E-mail:ptw@star.rl.ac.uk