1 files changed, 58 insertions, 0 deletions
diff --git a/src/slalib/cr2tf.f b/src/slalib/cr2tf.f
new file mode 100644
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+++ b/src/slalib/cr2tf.f
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+      SUBROUTINE sla_CR2TF (NDP, ANGLE, SIGN, IHMSF)
+*+
+*     - - - - - -
+*      C R 2 T F
+*     - - - - - -
+*
+*  Convert an angle in radians into hours, minutes, seconds
+*  (single precision)
+*
+*  Given:
+*     NDP       int      number of decimal places of seconds
+*     ANGLE     real     angle in radians
+*
+*  Returned:
+*     SIGN      char     '+' or '-'
+*     IHMSF     int(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 REAL 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=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 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_CD2TF
+*
+*  P.T.Wallace   Starlink   18 March 1999
+*
+*  Copyright (C) 1999 Rutherford Appleton Laboratory
+*-
+
+      IMPLICIT NONE
+
+      INTEGER NDP
+      REAL ANGLE
+      CHARACTER SIGN*(*)
+      INTEGER IHMSF(4)
+
+*  Turns to radians
+      REAL T2R
+      PARAMETER (T2R=6.283185307179586476925287)
+
+
+
+*  Scale then use days to h,m,s routine
+      CALL sla_CD2TF(NDP,ANGLE/T2R,SIGN,IHMSF)
+
+      END