Trailing-Edge
-
PDP-10 Archives
-
decuslib20-02
-
decus/20-0026/se13.doc
There are 2 other files named se13.doc in the archive. Click here to see a list.
SUBROUTINE SE13
PURPOSE
TO COMPUTE A VECTOR OF SMOOTHED FUNCTION VALUES GIVEN A
VECTOR OF FUNCTION VALUES WHOSE ENTRIES CORRESPOND TO
EQUIDISTANTLY SPACED ARGUMENT VALUES.
USAGE
CALL SE13(Y,Z,NDIM,IER)
DESCRIPTION OF PARAMETERS
Y - GIVEN VECTOR OF FUNCTION VALUES (DIMENSION NDIM)
Z - RESULTING VECTOR OF SMOOTHED FUNCTION VALUES
(DIMENSION NDIM)
NDIM - DIMENSION OF VECTORS Y AND Z
IER - RESULTING ERROR PARAMETER
IER = -1 - NDIM IS LESS THAN 3
IER = 0 - NO ERROR
REMARKS
(1) IF IER=-1 THERE HAS BEEN NO COMPUTATION.
(2) Z CAN HAVE THE SAME STORAGE ALLOCATION AS Y. IF Y
IS DISTINCT FROM Z, THEN IT IS NOT DESTROYED.
SUBROUTINES AND SUBPROGRAMS REQUIRED
NONE
METHOD
IF X IS THE (SUPPRESSED) VECTOR OF ARGUMENT VALUES, THEN
EXCEPT AT THE ENDPOINTS X(1) AND X(NDIM), EACH SMOOTHED
VALUE Z(I) IS OBTAINED BY EVALUATING AT X(I) THE LEAST-
SQUARES POLYNOMIAL OF DEGREE 1 RELEVANT TO THE 3 SUCCESSIVE
POINTS (X(I+K),Y(I+K)) K = -1,0,1. (SEE HILDEBRAND, F.B.,
INTRODUCTION TO NUMERICAL ANALYSIS, MC GRAW-HILL, NEW YORK/
TORONTO/LONDON, 1956, PP. 295-302.)