1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
SUBROUTINE sla_DR2TF (NDP, ANGLE, SIGN, IHMSF)
*+
* - - - - - -
* D R 2 T F
* - - - - - -
*
* Convert an angle in radians to hours, minutes, seconds
* (double precision)
*
* 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). For example, on the VAX, 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 the 32-bit integer IHMSF(4).
*
* 3) The absolute value of ANGLE may exceed 2pi. In cases where it
* does not, it is up to the caller to test for and handle the
* case where ANGLE is very nearly 2pi and rounds up to 24 hours,
* by testing for IHMSF(1)=24 and setting IHMSF(1-4) to zero.
*
* Called: sla_DD2TF
*
* P.T.Wallace Starlink 19 March 1999
*
* Copyright (C) 1995 Rutherford Appleton Laboratory
*-
IMPLICIT NONE
INTEGER NDP
DOUBLE PRECISION ANGLE
CHARACTER SIGN*(*)
INTEGER IHMSF(4)
* Turns to radians
DOUBLE PRECISION T2R
PARAMETER (T2R=6.283185307179586476925287D0)
* Scale then use days to h,m,s routine
CALL sla_DD2TF(NDP,ANGLE/T2R,SIGN,IHMSF)
END
|
