https://github.com/cran/fields
Tip revision: 66561c3c33070df2578182fed373cf04d4a7c1c6 authored by Douglas Nychka on 13 December 2016, 06:57:09 UTC
version 8.7
version 8.7
Tip revision: 66561c3
ifind.f
c fields, Tools for spatial data
c Copyright 2015, Institute for Mathematics Applied Geosciences
c University Corporation for Atmospheric Research
c Licensed under the GPL -- www.gpl.org/licenses/gpl.html
INTEGER FUNCTION IFIND(X,XK,N)
C FIND I SUCH THAT XK(I) LE X LT XK(I+1)
C IFIND=0 IF X LT XK(1)
C IFIND=N IF X GT XK(N)
C J F MONAHAN JAN 1982 DEPT OF STAT, N C S U, RALEIGH, NC 27650
double precision X,XK(N)
IFIND=0
IF(X.LT.XK(1)) RETURN
IFIND=N
IF(X.GE.XK(N)) RETURN
IL=1
IU=N
1 IF(IU-IL.LE.1) GO TO 4
I=(IU+IL)/2
C IF(X-XK(I)) 2,5,3
IF( (X-XK(I)).eq.0) go to 5
IF( (X-XK(I)).gt.0) go to 3
C following used to have line number 2
IU=I
GO TO 1
3 IL=I
GO TO 1
4 IFIND=IL
RETURN
5 IFIND=I
RETURN
END