EXODUS/packages/seacas/libraries/mapvarlib/cntr.f

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

C=======================================================================
*DECK,CNTR
      SUBROUTINE CNTR (ITYPE,XX,YY,ZZ,XCNTR,YCNTR,ZCNTR)

C     ******************************************************************

C     SUBROUTINE TO FIND THE CENTER COORDINATES OF AN ELEMENT

C     Called by ELTON3, LDCENB, SRCH2D, SRCH3D

C     ******************************************************************

      DIMENSION XX(*), YY(*), ZZ(*)

C     ******************************************************************

C     SELECT ELEMENT TYPE

      GO TO (100, 110, 120, 130, 140, 150, 160, 170, 180, 190,
     &    200, 210, 150), ITYPE

C     3-NODE TRIANGLE

  100 CONTINUE
      XCNTR=(XX(1)+XX(2)+XX(3))/3.
      YCNTR=(YY(1)+YY(2)+YY(3))/3.
      ZCNTR=0.
      RETURN

C     6-NODE TRIANGLE

  110 CONTINUE
      XCNTR=-(XX(1)+XX(2)+XX(3))/9.+4.*(XX(4)+XX(5)+XX(6))/9.
      YCNTR=-(YY(1)+YY(2)+YY(3))/9.+4.*(YY(4)+YY(5)+YY(6))/9.
      ZCNTR=0.
      RETURN

C     4-NODE QUADRILATERAL

  120 CONTINUE
      XCNTR=(XX(1)+XX(2)+XX(3)+XX(4))/4.
      YCNTR=(YY(1)+YY(2)+YY(3)+YY(4))/4.
      ZCNTR=0.
      RETURN

C     8-NODE QUADRILATERAL

  130 CONTINUE
      XCNTR=-(XX(1)+XX(2)+XX(3)+XX(4))/4.+(XX(5)+XX(6)+XX(7)+XX(8))/2.
      YCNTR=-(YY(1)+YY(2)+YY(3)+YY(4))/4.+(YY(5)+YY(6)+YY(7)+YY(8))/2.
      ZCNTR=0.
      RETURN

C     9-NODE QUADRILATERAL

  140 CONTINUE
      XCNTR=XX(9)
      YCNTR=YY(9)
      ZCNTR=0.
      RETURN

C     4-NODE TETRAHEDRON OR SHELL

  150 CONTINUE
      XCNTR=(XX(1)+XX(2)+XX(3)+XX(4))/4.
      YCNTR=(YY(1)+YY(2)+YY(3)+YY(4))/4.
      ZCNTR=(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4))/4.
      RETURN

C     10-NODE TETRAHEDRON

  160 CONTINUE
      XCNTR=-(XX(1)+XX(2)+XX(3)+XX(4))/8.+(XX(5)+XX(6)+XX(7)+XX(8)+
     1XX(9)+XX(10))/4.
      YCNTR=-(YY(1)+YY(2)+YY(3)+YY(4))/8.+(YY(5)+YY(6)+YY(7)+YY(8)+
     1YY(9)+YY(10))/4.
      ZCNTR=-(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4))/8.+(ZZ(5)+ZZ(6)+ZZ(7)+ZZ(8)+
     1ZZ(9)+ZZ(10))/4.
      RETURN

C     6-NODE PRISM

  170 CONTINUE
      XCNTR=(XX(1)+XX(2)+XX(3)+XX(4)+XX(5)+XX(6))/6.
      YCNTR=(YY(1)+YY(2)+YY(3)+YY(4)+YY(5)+YY(6))/6.
      ZCNTR=(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4)+ZZ(5)+ZZ(6))/6.
      RETURN

C     15-NODE PRISM

  180 CONTINUE
      XCNTR=-2.*(XX(1)+XX(2)+XX(3)+XX(4)+XX(5)+XX(6))/9.+
     12.*(XX(7)+XX(8)+XX(9)+XX(13)+XX(14)+XX(15))/9.+
     2(XX(10)+XX(11)+XX(12))/3.
      YCNTR=-2.*(YY(1)+YY(2)+YY(3)+YY(4)+YY(5)+YY(6))/9.+
     12.*(YY(7)+YY(8)+YY(9)+YY(13)+YY(14)+YY(15))/9.+
     2(YY(10)+YY(11)+YY(12))/3.
      ZCNTR=-2.*(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4)+ZZ(5)+ZZ(6))/9.+
     12.*(ZZ(7)+ZZ(8)+ZZ(9)+ZZ(13)+ZZ(14)+ZZ(15))/9.+
     2(ZZ(10)+ZZ(11)+ZZ(12))/3.
      RETURN

C     8-NODE HEX

  190 CONTINUE
      XCNTR=(XX(1)+XX(2)+XX(3)+XX(4)+XX(5)+XX(6)+XX(7)+XX(8))/8.
      YCNTR=(YY(1)+YY(2)+YY(3)+YY(4)+YY(5)+YY(6)+YY(7)+YY(8))/8.
      ZCNTR=(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4)+ZZ(5)+ZZ(6)+ZZ(7)+ZZ(8))/8.
      RETURN

C     20-NODE HEX

  200 CONTINUE
      XCNTR=-(XX(1)+XX(2)+XX(3)+XX(4)+XX(5)+XX(6)+XX(7)+XX(8))/4.+
     1(XX(9)+XX(10)+XX(11)+XX(12)+XX(13)+XX(14)+XX(15)+XX(16)+XX(17)+
     2XX(18)+XX(19)+XX(20))/4.
      YCNTR=-(YY(1)+YY(2)+YY(3)+YY(4)+YY(5)+YY(6)+YY(7)+YY(8))/4.+
     1(YY(9)+YY(10)+YY(11)+YY(12)+YY(13)+YY(14)+YY(15)+YY(16)+YY(17)+
     2YY(18)+YY(19)+YY(20))/4.
      ZCNTR=-(ZZ(1)+ZZ(2)+ZZ(3)+ZZ(4)+ZZ(5)+ZZ(6)+ZZ(7)+ZZ(8))/4.+
     1(ZZ(9)+ZZ(10)+ZZ(11)+ZZ(12)+ZZ(13)+ZZ(14)+ZZ(15)+ZZ(16)+ZZ(17)+
     2ZZ(18)+ZZ(19)+ZZ(20))/4.
      RETURN

C     27-NODE HEX

  210 CONTINUE
      XCNTR=XX(27)
      YCNTR=YY(27)
      ZCNTR=ZZ(27)
      RETURN

      END