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Дата изменения: Sat Dec 17 06:09:25 2005 Дата индексирования: Sun Apr 10 22:52:38 2016 Кодировка: Поисковые слова: arp 220 |
The function returns the ordinal position of any given item in an integer set. If the item does not appear in the set, the function returns -1.
SETS
VARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- item I An item to locate within a set. set I A set to search for a given item. The function returns the ordinal position of item within the set.
item is an integer to be located within a set. set is an integer CSPICE set that is to be searched for the occurrence of item. set must be declared as an integer SpiceCell.
The function returns the ordinal position of item within set. Ordinal positions range from 0 to N-1, where N is the cardinality of the set. If item is not an element of set, the function returns -1.
None.
A natural ordering can be imposed upon the the elements of any CSPICE set, be it integer, character or double precision. For character strings the ASCII collating sequence serves as the ordering relation, for double precision and integer variables the arithmetic ordering is used. Given any element of a set, its location within this ordered sequence of elements is called its ordinal position within the set. In common mathematical usage, ordinal positions of elements in a set of cardinality N range from 1 to N. In C programs, it is much more convenient to use the range 0 to N-1; this is the convention used in CSPICE. For illustrative purposes suppose that set represents the set { 8, 1, 2, 9, 7, 4, 10 } The ordinal position of: 8 is 4 1 is 0 2 is 1 9 is 5 7 is 3 4 is 2 10 is 6
1) Obtain the ordinal positions shown in the table of the Particulars section above. #include "SpiceUsr.h" int main() { /. Declare an integer set and populate it with the elements shown above. ./ #define MAXSIZ 7 SPICEINT_CELL ( set, MAXSIZ ); SpiceInt inputs [MAXSIZ] = { 8, 1, 2, 9, 7, 4, 10 }; SpiceInt expected [MAXSIZ] = { 4, 0, 1, 5, 3, 2, 6 }; SpiceInt i; SpiceInt iElt; /. Create the set. ./ for ( i = 0; i < MAXSIZ; i++ ) { insrti_c ( inputs[i], &set ); } /. Examine the ordinal positions of the set's elements. Extract each element and verify that ordi_c gives the index at which the element is located. ./ for ( i = 0; i < card_c(&set); i++ ) { iElt = inputs[i]; if ( ordi_c(iElt, &set) != expected[i] ) { setmsg_c ( "Position of # was expected to be # " "but was actually #." ); errint_c ( "#", iElt ); errint_c ( "#", expected[i] ); errint_c ( "#", ordi_c(iElt,&set) ); sigerr_c ( "INVALID LOCATION" ); } } return ( 0 ); }
None.
1) If the input set argument is a SpiceCell of type other than integer, the error SPICE(TYPEMISMATCH) is signaled. 2) If the input set argument does not qualify as a CSPICE set, the error SPICE(NOTASET) will be signaled. CSPICE sets have their data elements sorted in increasing order and contain no duplicate data elements.
None.
N.J. Bachman (JPL) C.A. Curzon (JPL) H.A. Neilan (JPL) W.L. Taber (JPL) I.M. Underwood (JPL)
None.
-CSPICE Version 1.0.0, 07-AUG-2002 (NJB) (CAC) (HAN) (WLT) (IMU)
the ordinal position of an element in a set