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Diffstat (limited to 'src/slalib/prenut.f')
| -rw-r--r-- | src/slalib/prenut.f | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/src/slalib/prenut.f b/src/slalib/prenut.f new file mode 100644 index 0000000..96d6bdc --- /dev/null +++ b/src/slalib/prenut.f @@ -0,0 +1,48 @@ + SUBROUTINE sla_PRENUT (EPOCH, DATE, RMATPN) +*+ +* - - - - - - - +* P R E N U T +* - - - - - - - +* +* Form the matrix of precession and nutation (IAU1976/FK5) +* (double precision) +* +* Given: +* EPOCH dp Julian Epoch for mean coordinates +* DATE dp Modified Julian Date (JD-2400000.5) +* for true coordinates +* +* Returned: +* RMATPN dp(3,3) combined precession/nutation matrix +* +* Called: sla_PREC, sla_EPJ, sla_NUT, sla_DMXM +* +* Notes: +* +* 1) The epoch and date are TDB (loosely ET). +* +* 2) The matrix is in the sense V(true) = RMATPN * V(mean) +* +* P.T.Wallace Starlink April 1987 +* +* Copyright (C) 1995 Rutherford Appleton Laboratory +*- + + IMPLICIT NONE + + DOUBLE PRECISION EPOCH,DATE,RMATPN(3,3) + + DOUBLE PRECISION RMATP(3,3),RMATN(3,3),sla_EPJ + + + +* Precession + CALL sla_PREC(EPOCH,sla_EPJ(DATE),RMATP) + +* Nutation + CALL sla_NUT(DATE,RMATN) + +* Combine the matrices: PN = N x P + CALL sla_DMXM(RMATN,RMATP,RMATPN) + + END |