/* spks08.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* Table of constant values */

static integer c__6 = 6;
static integer c__1 = 1;

/* $Procedure SPKS08 ( S/P Kernel, subset, type 8 ) */
/* Subroutine */ int spks08_(integer *handle, integer *baddr, integer *eaddr, 
	doublereal *begin, doublereal *end)
{
    /* System generated locals */
    integer i__1, i__2, i__3;
    doublereal d__1, d__2;

    /* Builtin functions */
    integer i_dnnt(doublereal *);
    double d_int(doublereal *);

    /* Local variables */
    doublereal data[6];
    integer nrec;
    doublereal step;
    integer i__;
    extern /* Subroutine */ int chkin_(char *, ftnlen);
    doublereal ratio, start;
    extern /* Subroutine */ int dafada_(doublereal *, integer *), dafgda_(
	    integer *, integer *, integer *, doublereal *);
    integer degree, offset;
    extern /* Subroutine */ int chkout_(char *, ftnlen);
    extern logical return_(void);
    integer rec[2];

/* $ Abstract */

/*     Extract a subset of the data in an SPK segment of type 8 */
/*     into a new segment. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     SPK */
/*     DAF */

/* $ Keywords */

/*     EPHEMERIS */

/* $ Declarations */
/* $ Brief_I/O */

/*     Variable  I/O  Description */
/*     --------  ---  -------------------------------------------------- */
/*     HANDLE     I   Handle of file containing source segment. */
/*     BADDR      I   Beginning address in file of source segment. */
/*     EADDR      I   Ending address in file of source segment. */
/*     BEGIN      I   Beginning (initial epoch) of subset. */
/*     END        I   End (final epoch) of subset. */

/* $ Detailed_Input */

/*     HANDLE, */
/*     BADDR, */
/*     EADDR       are the file handle assigned to an SPK file, and the */
/*                 beginning and ending addresses of a segment within */
/*                 that file.  Together they determine a complete set of */
/*                 ephemeris data, from which a subset is to be */
/*                 extracted. */

/*     BEGIN, */
/*     END         are the initial and final epochs (ephemeris time) */
/*                 of the subset. */

/*                 The first epoch for which there will be ephemeris */
/*                 data in the new segment will be the greatest time */
/*                 in the source segment that is less than or equal */
/*                 to BEGIN. */

/*                 The last epoch for which there will be ephemeris */
/*                 data in the new segment will be the smallest time */
/*                 in the source segment that is greater than or equal */
/*                 to END. */

/* $ Detailed_Output */

/*     See $Files section. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1)  This routine relies on the caller to ensure that the */
/*         interval [BEGIN, END] is contained in the coverage */
/*         interval of the segment. */

/*     2)  If BEGIN > END, no data is written to the target file. */

/* $ Files */

/*     Data is extracted from the file connected to the input */
/*     handle, and written to the current DAF open for writing. */

/*     The segment descriptor and summary must already have been written */
/*     prior to calling this routine.  The segment must be ended */
/*     external to this routine. */

/* $ Particulars */

/*     This routine is intended solely for use as a utility by the */
/*     routine SPKSUB. */

/*     It transfers a subset of a type 08 SPK data segment to */
/*     a properly initialized segment of a second SPK file. */

/*     The exact structure of a segment of data type 08 is described */
/*     in the section on type 08 in the SPK Required Reading. */

/* $ Examples */

/*     This routine is intended only for use as a utility by SPKSUB. */
/*     To use this routine successfully, you must: */

/*        Open the SPK file from which to extract data. */
/*        Locate the segment from which data should be extracted. */

/*        Open the SPK file to which this data should be written. */
/*        Begin a new segment (array). */
/*        Write the summary information for the array. */

/*        Call this routine to extract the appropriate data from the */
/*        SPK open for read. */

/*        End the array to which this routine writes data. */

/*     Much of this procedure is carried out by the routine SPKSUB.  The */
/*     examples of that routine illustrate more fully the process */
/*     described above. */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     N.J. Bachman    (JPL) */
/*     J.M. Lynch      (JPL) */
/*     W.L. Taber      (JPL) */
/*     I.M. Underwood  (JPL) */

/* $ Version */

/* -    SPICELIB Version 2.1.0, 07-SEP-2001 (EDW) */

/*        Replaced DAFRDA call with DAFGDA. */
/*        Added IMPLICIT NONE. */

/* -    SPICELIB Version 2.0.0, 20-AUG-1994 (NJB) */

/*        Bug fix:  START value for output segment has been corrected. */
/*        Bug fix:  Sufficient bracketing states are now included in the */
/*        output segment to ensure duplication of states given by source */
/*        segment. */

/* -    SPICELIB Version 1.0.0, 08-AUG-1993 (NJB) (JML) (WLT) (IMU) */

/* -& */
/* $ Index_Entries */

/*     subset type_8 spk segment */

/* -& */
/* $ Revisions */

/* -& */

/*     SPICELIB functions */


/*     Local variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	return 0;
    } else {
	chkin_("SPKS08", (ftnlen)6);
    }

/*     Look up the following items: */

/*        -- The start epoch */
/*        -- The step size */
/*        -- The polynomial degree */
/*        -- The number of records in the segment */

    i__1 = *eaddr - 3;
    dafgda_(handle, &i__1, eaddr, data);
    start = data[0];
    step = data[1];
    degree = i_dnnt(&data[2]);
    nrec = i_dnnt(&data[3]);

/*     See whether there's any work to do; return immediately if not. */

    if (*end < *begin || *end < start || *begin > start + (nrec - 1) * step) {
	chkout_("SPKS08", (ftnlen)6);
	return 0;
    }

/*     Compute the index of the state having the last epoch */
/*     epoch less than or equal to BEGIN (or the initial epoch, */
/*     whichever comes last). This epoch corresponds to the first */
/*     state to be transferred. */

/* Computing MAX */
    d__1 = 0., d__2 = (*begin - start) / step;
    ratio = max(d__1,d__2);
/* Computing MIN */
    i__1 = (integer) ratio, i__2 = nrec - 1;
    rec[0] = min(i__1,i__2) + 1;

/*     Make sure that there are DEGREE/2 additional states to the left */
/*     of the one having index REC(1), if possible.  If not, take as */
/*     many states as we can. */

/* Computing MAX */
    i__1 = 1, i__2 = rec[0] - degree / 2;
    rec[0] = max(i__1,i__2);

/*     Make sure that REC(1) is small enough so that there are are at */
/*     least DEGREE+1 states in the segment. */

/* Computing MIN */
    i__1 = rec[0], i__2 = nrec - degree;
    rec[0] = min(i__1,i__2);

/*     Now compute the index of the state having the first epoch greater */
/*     than or equal to END (or the final epoch, whichever comes first). */
/*     This epoch corresponds to the last state to be transferred. */

    ratio = (*end - start) / step;
    if (ratio == d_int(&ratio)) {
/* Computing MIN */
	i__1 = (integer) ratio, i__2 = nrec - 1;
	rec[1] = min(i__1,i__2) + 1;
    } else {
/* Computing MIN */
	i__1 = (integer) ratio + 1, i__2 = nrec - 1;
	rec[1] = min(i__1,i__2) + 1;
    }

/*     Make sure that there are DEGREE/2 additional states to the right */
/*     of the one having index REC(2), if possible.  If not, take as */
/*     many states as we can. */

/* Computing MIN */
    i__1 = nrec, i__2 = rec[1] + degree / 2;
    rec[1] = min(i__1,i__2);

/*     Make sure that REC(2) is large enough so that there are are at */
/*     least DEGREE+1 states in the segment. */

/* Computing MAX */
    i__1 = rec[1], i__2 = degree + 1;
    rec[1] = max(i__1,i__2);

/*     Copy states REC(1) through REC(2) to the output file. */

    i__1 = rec[1];
    for (i__ = rec[0]; i__ <= i__1; ++i__) {
	offset = *baddr - 1 + (i__ - 1) * 6;
	i__2 = offset + 1;
	i__3 = offset + 6;
	dafgda_(handle, &i__2, &i__3, data);
	dafada_(data, &c__6);
    }

/*     Store the start time, step size, polynomial degree and the */
/*     number of records to end the segment. */

    d__1 = start + (rec[0] - 1) * step;
    dafada_(&d__1, &c__1);
    dafada_(&step, &c__1);
    d__1 = (doublereal) degree;
    dafada_(&d__1, &c__1);
    d__1 = (doublereal) (rec[1] - rec[0] + 1);
    dafada_(&d__1, &c__1);
    chkout_("SPKS08", (ftnlen)6);
    return 0;
} /* spks08_ */

