C
C***********************************************************************
C                 COPYRIGHT ATLANTIC RICHFIELD COMPANY 1991            *
C***********************************************************************
CTITLESAPEAKT -- FIND INDEXES OF PEAKS AND TROUGHS                      00020001
CA    AUTHOR       B. S. BOX                                            00030001
CA    DESIGNER     B. S. BOK                                            00040001
CA    LANGUAGE     FORTRAN                                              00050001
CA    SYSTEM       IBM                                                  00060001
CA    WRITTEN      AUGUST, 1990                                         00070001
C     REVISED      12-21-91 JJC - MODIFIED TO MEET EDP STANDARDS.
C                                                                       00080001
CA                                                                      00090001
CA    CALL SAPEAKT (A, NPNT, AMAX, NDX)                                 00100001
CA                                                                      00110001
CA         INPUT   A    = INPUT ARRAY                               R4  00120001
CA         INPUT   NPNT = NO. OF POINT OF ARRAY A                   I4  00130001
CA         OUTPUT  AMAX = VALUE OF HIGHEST PEAK                     R4  00140001
CA         IOUTPUT NDX  = INDEXES OF CONSEQUTIVE PEAK AND TROUGHS   I4  00150001
CA                                                                      00160001
CA    THIS SUBROUTINE IS TO FIND INDEXES OF PEAKS AND TROUGHS           00170001
C                                                                       00180001
C     REMARKS: FIRST AND LAST INDEXES ARE ALWAYS INCLUDED.              00190001
C              INDEX AFTER LAST PEAK (OR TROUGH) WILL BE SET ZERO       00200001
C**************************************************************
C                                                             *
C SUBROUTINES AND FUNCTIONS CALLED FROM THIS ROUTINE          *
C                                                             *
C NO SUBROUTINES OR FUNCTIONS CALLED FROM THIS PROGRAM UNIT   *
C                                                             *
C**************************************************************
C                                                                       00210001
      SUBROUTINE SAPEAKT (A, NPNT, AMAX, NDX)                           00130000
C                                                                       00140001
      IMPLICIT INTEGER (A-Z)                                            00150001
C                                                                       00160001
      DIMENSION A(NPNT), NDX(NPNT)                                      00190000
C
      REAL    A                                                         00170001
      REAL    AMAX                                                      00180001
C                                                                       00200001
      K = 0
      NDX(1) = 1
      IF (A(2) .LT. A(1)) K = 1
      AMAX = A(1)
      N2 = 2
C                                                                       00260000
C     FIND NEXT TROUGH                                                  00270000
C                                                                       00280000
 100  CONTINUE
      DO 120 N1 = N2, NPNT
         IF (A(N1) .GT. A(N1-1)) GO TO 140
 120  CONTINUE
      GO TO 200
 140  CONTINUE
      K = K + 1
      NDX(K) = N1 - 1
      N1 = N1 + 1
      IF (N1 .EQ. NPNT) GO TO 200
C                                                                       00370000
C     FIND NEXT PEAK                                                    00380000
C                                                                       00390000
      DO 160 N2 = N1, NPNT
         IF (A(N2) .LT. A(N2-1)) GO TO 180
 160  CONTINUE
      GO TO 200
 180  CONTINUE
      K = K + 1
      NDX(K) = N2 - 1
      AMAX = AMAX1 ( A(N2 - 1), AMAX )
      N2 = N2 + 1
      IF (N2 .LT. NPNT) GO TO 100
 200  CONTINUE
      K = K + 1
      NDX(K) = NPNT
      NDX(K + 1) = 0
C                                                                       00520000
C                                                                       00540000
      RETURN
      END