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Procedure
Abstract
Required_Reading
Keywords
Declarations
Brief_I/O
Detailed_Input
Detailed_Output
Parameters
Exceptions
Files
Particulars
Examples
Restrictions
Literature_References
Author_and_Institution
Version

Procedure

      FRMGET ( Frame get transformation )

      SUBROUTINE FRMGET ( INFRM, ET, XFORM, OUTFRM, FOUND )

Abstract

     Find the transformation from a user specified frame to
     another frame at a user specified epoch.

Required_Reading

     FRAMES

Keywords

     FRAMES

Declarations

      IMPLICIT NONE

      INCLUDE              'frmtyp.inc'

      INTEGER               INFRM
      DOUBLE PRECISION      ET
      DOUBLE PRECISION      XFORM ( 6, 6 )
      INTEGER               OUTFRM
      LOGICAL               FOUND

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     INFRM      I   The integer code for a SPICE reference frame.
     ET         I   An epoch in seconds past J2000.
     XFORM      O   A state transformation matrix.
     OUTFRM     O   The frame that XFORM transforms INFRM to.
     FOUND      O   TRUE if a frame transformation can be found.

Detailed_Input

     INFRM       is the SPICE ID-code for some reference frame.

     ET          is an epoch in ephemeris seconds past J2000 at
                 which the user wishes to retrieve a state
                 transformation matrix.

Detailed_Output

     XFORM       is a 6x6 matrix that transforms states relative to
                 INFRM to states relative to OUTFRM. (Assuming such a
                 transformation can be found.)

     OUTFRM      is the SPICE ID-code of a reference frame. The 6x6
                 matrix XFORM transforms states relative to INFRM to
                 states relative to OUTFRM. The state transformation
                 is achieved by multiplying XFORM on the right by a
                 state relative to INFRM.  This is easily accomplished
                 via the subroutine call shown below.

                    CALL MXVG ( XFORM, STATE, 6, 6, OSTATE )

     FOUND       is a logical flag indicating whether or not a
                 transformation matrix could be found from INFRM to
                 some other frame. If a transformation matrix cannot
                 be found OUTFRM will be set to zero, FOUND will be
                 set to FALSE and XFORM will be returned as the zero
                 matrix.

Parameters

     See include file.

Exceptions

     1) If a transformation matrix cannot be located, then FOUND will
        be set to FALSE, OUTFRM will be set to zero and XFORM will be
        set to the zero 6x6 matrix.

     2) If the class of the requested frame is not recognized the
        exception 'SPICE(UNKNOWNFRAMETYPE)' will be signaled.

Files

     LSK, SCLK, PCK, FK, SPK, and/or CK kernels may need to be loaded
     to provide the needed frame definition and transformation data.

Particulars

     This is a low level routine used for determining a chain of state
     transformation matrices from one frame to another.

Examples

     See FRMCHG.

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman    (JPL)
     B.V. Semenov    (JPL)
     W.L. Taber      (JPL)

Version

    SPICELIB Version 4.0.0, 05-JAN-2014 (BVS)

        To prevent operations with un-initialized DP numbers, wrapped
        IF ( .NOT. FAILED() ) ... END IF around output matrix
        transposition/re-assignment operations in all branches where
        the routine returning the matrix might fail.

        Added zero-ing out the output matrix in cases of a failed or
        .NOT. FOUND transformation look ups.

    SPICELIB Version 3.0.0, 18-DEC-2004 (NJB)

        Added the new frame type 'DYN' to the list of frame
        types recognized by FRMGET.

    SPICELIB Version 2.0.0, 03-APR-1997 (WLT)

        Added the new frame type 'TK' to the list of frame
        types recognized by FRMGET.  In addition the routine
        now checks FAILED after "getting" the frame transformation.

    SPICELIB Version 1.0.0, 20-OCT-1994 (WLT)
Wed Apr  5 17:46:38 2017