a2af

erfa.a2af(ndp, angle)

Decompose radians into degrees, arcminutes, arcseconds, fraction.

Parameters:

ndpint array

angledouble array

Returns:

signchar array

idmsfint array

Notes

Wraps ERFA function eraA2af. The ERFA documentation is:

- - - - - - - -
 e r a A 2 a f
- - - - - - - -

Decompose radians into degrees, arcminutes, arcseconds, fraction.

Given:
   ndp     int     resolution (Note 1)
   angle   double  angle in radians

Returned:
   sign    char         '+' or '-'
   idmsf   int[4]  degrees, arcminutes, arcseconds, fraction

Notes:

1) The argument ndp is interpreted as follows:

   ndp         resolution
    :      ...0000 00 00
   -7         1000 00 00
   -6          100 00 00
   -5           10 00 00
   -4            1 00 00
   -3            0 10 00
   -2            0 01 00
   -1            0 00 10
    0            0 00 01
    1            0 00 00.1
    2            0 00 00.01
    3            0 00 00.001
    :            0 00 00.000...

2) The largest positive useful value for ndp is determined by the
   size of angle, the format of doubles on the target platform, and
   the risk of overflowing idmsf[3].  On a typical platform, for
   angle up to 2pi, the available floating-point precision might
   correspond to ndp=12.  However, the practical limit is typically
   ndp=9, set by the capacity of a 32-bit int, or ndp=4 if int is
   only 16 bits.

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 360 degrees,
   by testing for idmsf[0]=360 and setting idmsf[0-3] to zero.

Called:
   eraD2tf      decompose days to hms

This revision:  2021 May 11

Copyright (C) 2013-2023, NumFOCUS Foundation.
Derived, with permission, from the SOFA library.  See notes at end of file.