https://github.com/cran/fields
Tip revision: 6769ffc81115fbf0bf7d9c566cf7ac81be0049dc authored by Doug Nychka on 25 July 2005, 00:00:00 UTC
version 3.04
version 3.04
Tip revision: 6769ffc
hsort.f
SUBROUTINE HSORT(K,N)
C HEAPSORT ALGORITHM FOR SORTING ON VECTOR OF KEYS K OF LENGTH N
C J F MONAHAN TRANSCRIBED FROM KNUTH, VOL 2, PP 146-7.
REAL*8 K(1),KK
INTEGER R
IF(N.LE.1) RETURN
L=N/2+1
R=N
2 IF(L.GT.1) GO TO 1
KK=K(R)
K(R)=K(1)
R=R-1
IF(R.EQ.1) GO TO 9
GO TO 3
1 L=L-1
KK=K(L)
3 J=L
4 I=J
J=2*J
IF(J-R) 5,6,8
5 IF(K(J).LT.K(J+1)) J=J+1
6 IF(KK.GT.K(J)) GO TO 8
7 K(I)=K(J)
GO TO 4
8 K(I)=KK
GO TO 2
9 K(1)=KK
RETURN
END