C SE35 10
C ..................................................................SE35 20
C SE35 30
C SUBROUTINE SE35 SE35 40
C SE35 50
C PURPOSE SE35 60
C TO COMPUTE A VECTOR OF SMOOTHED FUNCTION VALUES GIVEN A SE35 70
C VECTOR OF FUNCTION VALUES WHOSE ENTRIES CORRESPOND TO SE35 80
C EQUIDISTANTLY SPACED ARGUMENT VALUES. SE35 90
C SE35 100
C USAGE SE35 110
C CALL SE35(Y,Z,NDIM,IER) SE35 120
C SE35 130
C DESCRIPTION OF PARAMETERS SE35 140
C Y - GIVEN VECTOR OF FUNCTION VALUES (DIMENSION NDIM) SE35 150
C Z - RESULTING VECTOR OF SMOOTHED FUNCTION VALUES SE35 160
C (DIMENSION NDIM) SE35 170
C NDIM - DIMENSION OF VECTORS Y AND Z SE35 180
C IER - RESULTING ERROR PARAMETER SE35 190
C IER = -1 - NDIM IS LESS THAN 5 SE35 200
C IER = 0 - NO ERROR SE35 210
C SE35 220
C REMARKS SE35 230
C (1) IF IER=-1 THERE HAS BEEN NO COMPUTATION. SE35 240
C (2) Z CAN HAVE THE SAME STORAGE ALLOCATION AS Y. IF Y IS SE35 250
C DISTINCT FROM Z, THEN IT IS NOT DESTROYED. SE35 260
C SE35 270
C SUBROUTINE AND FUNCTION SUBPROGRAMS REQUIRED SE35 280
C NONE SE35 290
C SE35 300
C METHOD SE35 310
C IF X IS THE (SUPPRESSED) VECTOR OF ARGUMENT VALUES, THEN SE35 320
C EXCEPT AT THE POINTS X(1),X(2),X(NDIM-1) AND X(NDIM), EACH SE35 330
C SMOOTHED VALUE Z(I) IS OBTAINED BY EVALUATING AT X(I) THE SE35 340
C LEAST-SQUARES POLYNOMIAL OF DEGREE 3 RELEVANT TO THE 5 SE35 350
C SUCCESSIVE POINTS (X(I+K),Y(I+K)) K = -2,-1,...,2. (SEE SE35 360
C HILDEBRAND, F.B., INTRODUCTION TO NUMERICAL ANALYSIS, SE35 370
C MC GRAW-HILL, NEW YORK/TORONTO/LONDON, 1956, PP. 295-302.) SE35 380
C SE35 390
C ..................................................................SE35 400
C SE35 410
SUBROUTINE SE35(Y,Z,NDIM,IER) SE35 420
C SE35 430
C SE35 440
DIMENSION Y(1),Z(1) SE35 450
C SE35 460
C TEST OF DIMENSION SE35 470
IF(NDIM-5)4,1,1 SE35 480
C SE35 490
C PREPARE LOOP SE35 500
1 B=Y(1) SE35 510
C=Y(2) SE35 520
C SE35 530
C START LOOP SE35 540
DO 3 I=5,NDIM SE35 550
A=B SE35 560
B=C SE35 570
C=Y(I-2) SE35 580
C SE35 590
C GENERATE FOURTH CENTRAL DIFFERENCE SE35 600
D=C-B-Y(I-1) SE35 610
D=D+D+C SE35 620
D=D+D+A+Y(I) SE35 630
C SE35 640
C CHECK FIRST TWO COMPONENTS SE35 650
IF(I-5)2,2,3 SE35 660
2 Z(1)=A-.01428571*D SE35 670
Z(2)=B+.05714286*D SE35 680
3 Z(I-2)=C-.08571429*D SE35 690
C END OF LOOP SE35 700
C SE35 710
C UPDATE LAST TWO COMPONENTS SE35 720
Z(NDIM-1)=Y(NDIM-1)+.05714286*D SE35 730
Z(NDIM)=Y(NDIM)-.01428571*D SE35 740
IER=0 SE35 750
RETURN SE35 760
C SE35 770
C ERROR EXIT IN CASE NDIM IS LESS THAN 5 SE35 780
4 IER=-1 SE35 790
RETURN SE35 800
END SE35 810