CTITLEARMEAN -- SLIDING MEAN                                            00010001
C***********************************************************************
C                 COPYRIGHT ATLANTIC RICHFIELD COMPANY 1991            *
C***********************************************************************
CA    AUTHOR                 STU NELAN                                  00020000
CA    DESIGNER               STU NELAN                                  00030000
CA    LANGUAGE               FORTRAN                                    00040001
CA    SYSTEM                 IBM AND CRAY                               00050001
CA    WRITTEN                                                           00060000
C     REVISED                07-11-86 ESN. FOR USE ON THE IBM.          00070001
CA                                                                      00080000
CA                                                                      00090000
CA    CALL ARMEAN  (A, B, N, WL)                                        00100000
CA          INPUT   A = REAL ARRAY                                  R4  00110000
CA          OUTPUT  B = REAL ARRAY                                  R4  00120000
CA          INPUT   N = NUMBER OF ELEMENTS IN A                     I4  00130000
CA          INPUT  WL = WINDOW LENGTH IN POINTS                     I4  00140000
CA                                                                      00150000
CA                                                                      00160000
CA       ARMEAN SLIDES A WINDOW OF 'WL' POINTS ALONG THE INPUT ARRAY A  00170000
CA       AND WRITES IN ARRAY B THE SUM OF VALUES DIVIDED BY             00180000
CA       THE NUMBER OF VALUES IN THE WINDOW. THE OUTPUT LENGTH OF B     00190000
CA       WILL BE EQUAL TO N - WL + 1                                    00200000
CAEND                                                                   00210000
      SUBROUTINE ARMEAN (A, B, N, WL)                                   00220000
C                                                                       00230000
      REAL  A  (1)                                                      00240000
      REAL  B  (1)                                                      00250000
C                                                                       00260000
      DOUBLE PRECISION  SUM                                             00270000
C                                                                       00280000
      INTEGER  WL                                                       00290000
C                                                                       00300000
      NSAMPS = N - WL + 1                                               00310000
      SUM = 0.0                                                         00320000
C                                                                       00330000
C     COMPUTE THE INITIAL AVERAGE                                       00340000
C                                                                       00350000
      DO 10 I = 1, WL                                                   00360000
      SUM = SUM + A(I)                                                  00370000
   10 CONTINUE                                                          00380000
C                                                                       00390000
      B(1) = SUM / WL                                                   00400000
      IS = 1                                                            00410000
      IE = WL + 1                                                       00420000
C                                                                       00430000
C     COMPUTE THE RUNNING SUMS AND AVERAGES                             00440000
C                                                                       00450000
      DO 20 I = 2, NSAMPS                                               00460000
      SUM = SUM - A(IS) + A(IE)                                         00470000
      IS = IS + 1                                                       00480000
      IE = IE + 1                                                       00490000
      B(I) = SUM / WL                                                   00500000
   20 CONTINUE                                                          00510000
C                                                                       00520000
      RETURN                                                            00530000
C                                                                       00540000
      END                                                               00550000