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

#include "f2c.h"

/* $Procedure      WNRELD ( Compare two DP windows ) */
logical wnreld_(doublereal *a, char *op, doublereal *b, ftnlen op_len)
{
    /* System generated locals */
    integer i__1;
    logical ret_val;

    /* Builtin functions */
    integer s_cmp(char *, char *, ftnlen, ftnlen);

    /* Local variables */
    integer i__, acard, bcard;
    extern integer cardd_(doublereal *);
    extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
	     ftnlen, ftnlen);
    logical equal;
    extern logical wnincd_(doublereal *, doublereal *, doublereal *);
    extern /* Subroutine */ int sigerr_(char *, ftnlen), chkout_(char *, 
	    ftnlen), setmsg_(char *, ftnlen);
    logical subset;
    extern logical return_(void);

/* $ Abstract */

/*      Compare two double precision windows. */

/* $ 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 */

/*      WINDOWS */

/* $ Keywords */

/*      WINDOWS */

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

/*      VARIABLE  I/O  DESCRIPTION */
/*      --------  ---  -------------------------------------------------- */
/*      A          I   First window. */
/*      OP         I   Comparison operator. */
/*      B          I   Second window. */

/*      The function returns the result of comparison: A (OP) B. */

/* $ Detailed_Input */

/*      A, */
/*      B           are windows, each of which contains zero or more */
/*                  intervals. */

/*      OP          is a comparison operator, indicating the way in */
/*                  which the input sets are to be compared. OP may */
/*                  be any of the following: */

/*                      Operator             Meaning */
/*                      --------  ------------------------------------- */
/*                        '='     A = B is true if A and B are equal */
/*                                (contain the same intervals). */

/*                        '<>'    A <> B is true if A and B are not */
/*                                equal. */

/*                        '<='    A <= B is true if A is a subset of B. */

/*                        '<'     A < B is true is A is a proper subset */
/*                                of B. */

/*                        '>='    A >= B is true if B is a subset of A. */

/*                        '>'     A > B is true if B is a proper subset */
/*                                of A. */

/* $ Detailed_Output */

/*      The function returns the result of the comparison. */

/* $ Parameters */

/*      None. */

/* $ Particulars */

/*      This function is true whenever the specified relationship */
/*      between the input windows, A and B, is satisfied. For example, */
/*      the expression */

/*           WNRELD ( NEEDED, '<=', AVAIL ) */

/*      is true whenever the window NEEDED is a subset of the window */
/*      AVAIL. One window is a subset of another window if each of */
/*      the intervals in the first window is included in one of the */
/*      intervals in the second window. In addition, the first window */
/*      is a proper subset of the second if the second window contains */
/*      at least one point not contained in the first window. (Thus, */
/*      '<' implies '<=', and '>' implies '>='.) */

/*      The following pairs of expressions are equivalent. */

/*           WNRELD ( A, '>', B ) */
/*           WNRELD ( B, '<', A ) */

/*           WNRELD ( A, '>=', B ) */
/*           WNRELD ( B, '<=', A ) */

/* $ Examples */

/*      Let A contain the intervals */

/*            [ 1, 3 ]  [ 7, 11 ]  [ 23, 27 ] */

/*      Let B and C contain the intervals */

/*            [ 1, 2 ]  [ 9, 9 ]  [ 24, 27 ] */

/*      Let D contain the intervals */

/*            [ 5, 10 ]  [ 15, 25 ] */

/*      Finally, let E and F be empty windows (containing no intervals). */

/*      Because B and C contain the same intervals, */

/*            WNRELD ( B, '=',  C ) */
/*            WNRELD ( B, '<=', C ) */
/*            WNRELD ( B, '>=', C ) */

/*      are all true, while */

/*            WNRELD ( B, '<>', C ) */

/*      is false. Because neither B nor C contains any points not also */
/*      contained by the other, neither is a proper subset of the other. */
/*      Thus, */

/*            WNRELD ( B, '<', C ) */
/*            WNRELD ( B, '>', C ) */

/*      are both false. */

/*      Every point contained in B and C is also contained in A. Thus, */

/*            WNRELD ( B, '<=', A ) */
/*            WNRELD ( A, '>=', C ) */

/*      are both true. In addition, A contains points not contained in */
/*      B and C. (That is, the differences A-B and A-C are not empty.) */
/*      Thus, B and C are peoper subsets of A as well, and */

/*            WNRELD ( B, '<', A ) */
/*            WNRELD ( A, '>', B ) */

/*      are both true. */

/*      Although A and D have points in common, neither contains the */
/*      other. Thus */

/*            WNRELD ( A, '=',  D ) */
/*            WNRELD ( A, '<=', D ) */
/*            WNRELD ( A, '>=', D ) */

/*      are all false. */

/*      In addition, any window is equal to itself, a subset of itself, */
/*      and a superset of itself. Thus, */

/*            WNRELD ( A, '=',  A ) */
/*            WNRELD ( A, '<=', A ) */
/*            WNRELD ( A, '>=', A ) */

/*      are always true. However, no window is a proper subset or a */
/*      proper superset of itself. Thus, */

/*            WNRELD ( A, '<', A ) */
/*            WNRELD ( A, '>', A ) */

/*      are always false. */

/*      Finally, an empty window is a a proper subset of any window */
/*      except another empty window. Thus, */

/*            WNRELD ( E, '<', A ) */

/*      is true, but */

/*            WNRELD ( E, '<', F ) */

/*      is false. */

/* $ Exceptions */

/*      If the relational operator is not recognized, the error */
/*      SPICE(INVALIDOPERATION) is signalled. */

/* $ Files */

/*      None. */

/* $ Restrictions */

/*      None. */

/* $ Literature_References */

/*      None. */

/* $ Author_and_Institution */

/*      H.A. Neilan     (JPL) */
/*      W.L. Taber      (JPL) */
/*      I.M. Underwood  (JPL) */

/* $ Version */

/* -     SPICELIB Version 1.1.0, 17-MAY-1994 (HAN) */

/*         Set the default function value to either 0, 0.0D0, .FALSE., */
/*         or blank depending on the type of the function. */

/* -     SPICELIB Version 1.0.1, 10-MAR-1992 (WLT) */

/*         Comment section for permuted index source lines was added */
/*         following the header. */

/* -     SPICELIB Version 1.0.0, 31-JAN-1990 (WLT) (IMU) */

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

/*     compare two d.p. windows */

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

/* -     Beta Version 2.0.0, 2-FEB-1989 (HAN) */

/*         If the relational operator is not recognized, an error is */
/*         signalled. The previous version returned .FALSE. as the */
/*         function value, and no error was signalled. */

/*         Also, the Required_Reading section has been changed to */
/*         include WINDOWS as the required reading for the module. */

/* -& */

/*     SPICELIB functions */


/*     Local variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	ret_val = FALSE_;
	return ret_val;
    } else {
	chkin_("WNRELD", (ftnlen)6);
	ret_val = FALSE_;
    }

/*     Find the cardinality of the input windows. */

    acard = cardd_(a);
    bcard = cardd_(b);

/*     A and B are equal if they contain exactly the same intervals. */
/*     We need to know this for nearly every relationship, so find out */
/*     before going any further. */

    if (acard != bcard) {
	equal = FALSE_;
    } else {
	equal = TRUE_;
	i__1 = acard;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    equal = equal && a[i__ + 5] == b[i__ + 5];
	}
    }

/*     Simple equality and inequality are trivial at this point. */

    if (s_cmp(op, "=", op_len, (ftnlen)1) == 0) {
	ret_val = equal;
    } else if (s_cmp(op, "<>", op_len, (ftnlen)2) == 0) {
	ret_val = ! equal;

/*     Subsets are a little trickier. A is a subset of B if every */
/*     interval in A is included in B. In addition, A is a proper */
/*     subset if A and B are not equal. */

    } else if (s_cmp(op, "<=", op_len, (ftnlen)2) == 0 || s_cmp(op, "<", 
	    op_len, (ftnlen)1) == 0) {
	subset = TRUE_;
	i__1 = acard;
	for (i__ = 1; i__ <= i__1; i__ += 2) {
	    subset = subset && wnincd_(&a[i__ + 5], &a[i__ + 6], b);
	}
	if (s_cmp(op, "<=", op_len, (ftnlen)2) == 0) {
	    ret_val = subset;
	} else {
	    ret_val = subset && ! equal;
	}

/*     A and B change places here... */

    } else if (s_cmp(op, ">=", op_len, (ftnlen)2) == 0 || s_cmp(op, ">", 
	    op_len, (ftnlen)1) == 0) {
	subset = TRUE_;
	i__1 = bcard;
	for (i__ = 1; i__ <= i__1; i__ += 2) {
	    subset = subset && wnincd_(&b[i__ + 5], &b[i__ + 6], a);
	}
	if (s_cmp(op, ">=", op_len, (ftnlen)2) == 0) {
	    ret_val = subset;
	} else {
	    ret_val = subset && ! equal;
	}

/*     An unrecognized operator always fails. */

    } else {
	setmsg_("Relational operator, *, is not recognized.", (ftnlen)42);
	errch_("*", op, (ftnlen)1, op_len);
	sigerr_("SPICE(INVALIDOPERATION)", (ftnlen)23);
	chkout_("WNRELD", (ftnlen)6);
	return ret_val;
    }
    chkout_("WNRELD", (ftnlen)6);
    return ret_val;
} /* wnreld_ */

