Convert an angle in radians to hours, minutes, seconds, fraction (double precision).
CALL:
CALL sla_DR2TF (NDP, ANGLE, SIGN, IHMSF)
GIVEN:
NDP
I
number of decimal places of seconds
ANGLE
D
angle in radians
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 ANGLE, the format of
DOUBLE PRECISION floating-point numbers on the target machine, and the risk of
overflowing IHMSF(4). On some architectures, for ANGLE up to 2pi, the available
floating-point precision corresponds roughly to NDP=12. However, the practical
limit is NDP=9, set by the capacity of a typical 32-bit IHMSF(4).
(3)
The absolute value of ANGLE may exceed $2\pi $.
In cases where it does not, it is up to the caller to test for and handle the case where
ANGLE is very nearly $2\pi $
and rounds up to 24 hours, by testing for IHMSF(1)=24 and setting IHMSF(1-4) to
zero.