C #PARITY V1A 15-FEB-72. C LAST UPDATE: C FUNCTION PARITY(N) C C *PURPOSE. C TO RETURN REAL VALUE + OR -1. AS THE INTEGER ARGUMENT C IS EVEN OR ODD. C C *PARAMETERS: C C N - THE INTEGER VALUE WHOSE PARITY IS TESTED. C C INPUT PARAMETERS: C N C OUTPUT PARAMETERS: C (FUNCTION VALUE ONLY) C C *METHOD. C STRAIGHTFORWARD. C C *ACCURACY. C C *RESTRICTIONS. C C *ERROR CONDITIONS. C C *NON STANDARD ROUTINES CALLED. C C *TYPICAL TIMES. C C *ORIGIN. M.R.MANNING. C C *COMMENTS. C THIS TRIVIAL ROUTINE WOULD NORMALLY BE PROVIDED IN C MACHINE LANGUAGE. THE FORTRAN VERSION IS GIVEN TO ALLOW C PORTABILITY OF PROGRAMS AND AS A LANGUAGE EXTENDING ROUTINE. C C #END. C C #START. PARITY=1. IF ( 2*(N/2) .EQ. N ) GO TO 20 PARITY=-1. 20 RETURN END