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author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
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committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /math/slalib/dd2tf.f | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/slalib/dd2tf.f')
-rw-r--r-- | math/slalib/dd2tf.f | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/math/slalib/dd2tf.f b/math/slalib/dd2tf.f new file mode 100644 index 00000000..e3227631 --- /dev/null +++ b/math/slalib/dd2tf.f @@ -0,0 +1,107 @@ + SUBROUTINE slDDTF (NDP, DAYS, SIGN, IHMSF) +*+ +* - - - - - - +* D D T F +* - - - - - - +* +* Convert an interval in days into hours, minutes, seconds +* (double precision) +* +* Given: +* NDP i number of decimal places of seconds +* DAYS d 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 DOUBLE PRECISION floating-point numbers +* on the target machine, and the risk of overflowing IHMSF(4). +* On some architectures, for DAYS up to 1D0, 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 DAYS may exceed 1D0. In cases where it +* does not, it is up to the caller to test for and handle the +* case where DAYS is very nearly 1D0 and rounds up to 24 hours, +* by testing for IHMSF(1)=24 and setting IHMSF(1-4) to zero. +* +* Last revision: 26 December 2004 +* +* Copyright P.T.Wallace. All rights reserved. +* +* License: +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation; either version 2 of the License, or +* (at your option) any later version. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program (see SLA_CONDITIONS); if not, write to the +* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +* Boston, MA 02110-1301 USA +* +* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. +*- + + IMPLICIT NONE + + INTEGER NDP + DOUBLE PRECISION DAYS + CHARACTER SIGN*(*) + INTEGER IHMSF(4) + +* Days to seconds + DOUBLE PRECISION D2S + PARAMETER (D2S=86400D0) + + INTEGER NRS,N + DOUBLE PRECISION RS,RM,RH,A,AH,AM,AS,AF + + + +* Handle sign + IF (DAYS.GE.0D0) THEN + SIGN='+' + ELSE + SIGN='-' + END IF + +* Field units in terms of least significant figure + NRS=1 + DO N=1,NDP + NRS=NRS*10 + END DO + RS=DBLE(NRS) + RM=RS*60D0 + RH=RM*60D0 + +* Round interval and express in smallest units required + A=ANINT(RS*D2S*ABS(DAYS)) + +* Separate into fields + AH=AINT(A/RH) + A=A-AH*RH + AM=AINT(A/RM) + A=A-AM*RM + AS=AINT(A/RS) + AF=A-AS*RS + +* Return results + IHMSF(1)=MAX(NINT(AH),0) + IHMSF(2)=MAX(MIN(NINT(AM),59),0) + IHMSF(3)=MAX(MIN(NINT(AS),59),0) + IHMSF(4)=MAX(NINT(MIN(AF,RS-1D0)),0) + + END |