You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
130 lines
3.3 KiB
130 lines
3.3 KiB
C Copyright(C) 1999-2020 National Technology & Engineering Solutions
|
|
C of Sandia, LLC (NTESS). Under the terms of Contract DE-NA0003525 with
|
|
C NTESS, the U.S. Government retains certain rights in this software.
|
|
C
|
|
C See packages/seacas/LICENSE for details
|
|
|
|
SUBROUTINE SRCHGE( LBLK,NE,X,IND,XV,IMIN,IMAX,NDIM,I,
|
|
* IL,IU,IT,INDX1,INDX2,XTST )
|
|
|
|
C-----------------------------------------------------------------------
|
|
|
|
C DESCRIPTION:
|
|
|
|
C PERFORM A BINARY SEARCH TO FIND THE ELEMENT NUMBER I
|
|
C OF A SORTED ARRAY FOR WHICH ALL ELEMENTS AT I OR ABOVE ARE
|
|
C GREATER OR EQUAL TO THAN SOME VALUE XV,
|
|
C WHILE ALL ELEMENTS BELOW I ARE LESS THAN THE VALUE.
|
|
|
|
C X(I-2) X(I-1) X(I) X(I+1) X(I+2)
|
|
C XV X>
|
|
|
|
C ASSUMED THAT THE ARRAY X HAS BEEN SORTED IN INCREASING ORDER,
|
|
C BUT THE ELEMENTS HAVE NOT BEEN MOVED.
|
|
C THE SORTED LIST IS DETERMINED BY THE ARRAY INDX,
|
|
C WHICH POSITIONS THE ORIGINAL UNSORTED X ARRAY ELEMENTS
|
|
C IN THE SORTED LIST. THUS, THE 5TH ELEMENT IN THE SORTED LIST IS
|
|
C X(IND(5))
|
|
|
|
C-----------------------------------------------------------------------
|
|
|
|
C INPUT:
|
|
|
|
C X - ARRAY IN UNSORTED ORDER
|
|
C IND - INDEX ARRAY GIVING THE ELEMENT ORDER IN THE SORTED LIST
|
|
C XV - X VALUE TO TEST AGAINST
|
|
C IMIN - THE LOWEST NUMBERED POSITION IN THE SORTED LIST TO TEST
|
|
C IMAX - THE HIGHEST NUMBERED POSITION IN THE SORTED LIST TO TEST
|
|
C NDIM - THE DIMENSION OF THE ARRAYS
|
|
|
|
C OUTPUT:
|
|
|
|
C I - THE FIRST POSITION IN THE SORTED LIST .GT. XV
|
|
|
|
C SCRATCH:
|
|
|
|
C IL
|
|
C IU
|
|
C IT
|
|
C INDX1
|
|
C INDX2
|
|
C XTST
|
|
|
|
C-----------------------------------------------------------------------
|
|
|
|
DIMENSION
|
|
* X(NDIM), IND(NDIM), XV(LBLK), I(LBLK)
|
|
DIMENSION
|
|
* IL(LBLK),IU(LBLK),IT(LBLK),INDX1(LBLK),INDX2(LBLK),
|
|
* XTST(LBLK)
|
|
|
|
IF (IMAX.EQ.0.OR.NDIM.EQ.0) THEN
|
|
DO J = 1, NE
|
|
I(J) = 0
|
|
ENDDO
|
|
RETURN
|
|
ENDIF
|
|
DO 25 J = 1, NE
|
|
IL(J) = IMIN
|
|
IU(J) = IMAX
|
|
INDX1(J) = J
|
|
25 CONTINUE
|
|
ILOOP = NE
|
|
1000 CONTINUE
|
|
|
|
DO 50 JJ = 1, ILOOP
|
|
INDX2(JJ) = INDX1(JJ)
|
|
J = INDX1(JJ)
|
|
IT(J) = (IU(J) + IL(J)) / 2
|
|
50 CONTINUE
|
|
DO 35 J = 1, NE
|
|
XTST(J) = X( IND(IT(J)) )
|
|
35 CONTINUE
|
|
|
|
IF ( ILOOP .GT. 64) THEN
|
|
|
|
ILP = 0
|
|
DO 60 JJ = 1, ILOOP
|
|
J = INDX2(JJ)
|
|
IF( XTST(J) .LT. XV(J) )THEN
|
|
IL(J) =IT(J) + 1
|
|
ELSE
|
|
IU(J) =IT(J) - 1
|
|
ENDIF
|
|
IF( IL(J) .LE. IU(J)) THEN
|
|
ILP = ILP + 1
|
|
INDX1(ILP) = J
|
|
ENDIF
|
|
60 CONTINUE
|
|
ELSE
|
|
|
|
ILP = 0
|
|
DO 51 JJ = 1, ILOOP
|
|
J = INDX2(JJ)
|
|
IF( XTST(J) .LT. XV(J) )THEN
|
|
IL(J) =IT(J) + 1
|
|
ELSE
|
|
IU(J) =IT(J) - 1
|
|
ENDIF
|
|
IF( IL(J) .LE. IU(J)) THEN
|
|
ILP = ILP + 1
|
|
INDX1(ILP) = J
|
|
ENDIF
|
|
51 CONTINUE
|
|
ENDIF
|
|
|
|
ILOOP = ILP
|
|
|
|
IF(ILOOP .NE. 0 )GO TO 1000
|
|
C RANGE HAD NARROWED TO 1 LOCATION. HOWEVER, THE POINT LAST TESTED
|
|
C COULD BE ABOVE, BELOW, OR ON THE SEARCH POINT. CHECK FOR PROPER CASE
|
|
DO 200 J = 1, NE
|
|
IF( XTST(J) .LT. XV(J) )THEN
|
|
I(J) = IT(J) + 1
|
|
ELSE
|
|
I(J) = IT(J)
|
|
ENDIF
|
|
200 CONTINUE
|
|
|
|
RETURN
|
|
END
|
|
|