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99 lines
3.4 KiB
Fortran
99 lines
3.4 KiB
Fortran
*DECK DY
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SUBROUTINE DY (U, IDMN, I, J, UYYY, UYYYY)
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C***BEGIN PROLOGUE DY
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C***SUBSIDIARY
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C***PURPOSE Subsidiary to SEPELI
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C***LIBRARY SLATEC
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C***TYPE SINGLE PRECISION (DY-S)
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C***AUTHOR (UNKNOWN)
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C***DESCRIPTION
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C
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C This program computes second order finite difference
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C approximations to the third and fourth Y
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C partial derivatives of U at the (I,J) mesh point.
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C
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C***SEE ALSO SEPELI
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C***ROUTINES CALLED (NONE)
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C***COMMON BLOCKS SPLPCM
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C***REVISION HISTORY (YYMMDD)
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C 801001 DATE WRITTEN
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C 891214 Prologue converted to Version 4.0 format. (BAB)
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C 900402 Added TYPE section. (WRB)
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C***END PROLOGUE DY
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C
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COMMON /SPLPCM/ KSWX ,KSWY ,K ,L ,
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1 AIT ,BIT ,CIT ,DIT ,
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2 MIT ,NIT ,IS ,MS ,
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3 JS ,NS ,DLX ,DLY ,
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4 TDLX3 ,TDLY3 ,DLX4 ,DLY4
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DIMENSION U(IDMN,*)
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C***FIRST EXECUTABLE STATEMENT DY
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IF (J.GT.2 .AND. J.LT.(L-1)) GO TO 50
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IF (J .EQ. 1) GO TO 10
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IF (J .EQ. 2) GO TO 30
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IF (J .EQ. L-1) GO TO 60
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IF (J .EQ. L) GO TO 80
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C
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C COMPUTE PARTIAL DERIVATIVE APPROXIMATIONS AT Y=C
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C
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10 IF (KSWY .EQ. 1) GO TO 20
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UYYY = (-5.0*U(I,1)+18.0*U(I,2)-24.0*U(I,3)+14.0*U(I,4)-
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1 3.0*U(I,5))/TDLY3
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UYYYY = (3.0*U(I,1)-14.0*U(I,2)+26.0*U(I,3)-24.0*U(I,4)+
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1 11.0*U(I,5)-2.0*U(I,6))/DLY4
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RETURN
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C
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C PERIODIC AT X=A
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C
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20 UYYY = (-U(I,L-2)+2.0*U(I,L-1)-2.0*U(I,2)+U(I,3))/TDLY3
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UYYYY = (U(I,L-2)-4.0*U(I,L-1)+6.0*U(I,1)-4.0*U(I,2)+U(I,3))/DLY4
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RETURN
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C
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C COMPUTE PARTIAL DERIVATIVE APPROXIMATIONS AT Y=C+DLY
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C
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30 IF (KSWY .EQ. 1) GO TO 40
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UYYY = (-3.0*U(I,1)+10.0*U(I,2)-12.0*U(I,3)+6.0*U(I,4)-U(I,5))/
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1 TDLY3
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UYYYY = (2.0*U(I,1)-9.0*U(I,2)+16.0*U(I,3)-14.0*U(I,4)+6.0*U(I,5)-
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1 U(I,6))/DLY4
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RETURN
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C
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C PERIODIC AT Y=C+DLY
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C
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40 UYYY = (-U(I,L-1)+2.0*U(I,1)-2.0*U(I,3)+U(I,4))/TDLY3
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UYYYY = (U(I,L-1)-4.0*U(I,1)+6.0*U(I,2)-4.0*U(I,3)+U(I,4))/DLY4
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RETURN
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C
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C COMPUTE PARTIAL DERIVATIVE APPROXIMATIONS ON THE INTERIOR
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C
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50 CONTINUE
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UYYY = (-U(I,J-2)+2.0*U(I,J-1)-2.0*U(I,J+1)+U(I,J+2))/TDLY3
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UYYYY = (U(I,J-2)-4.0*U(I,J-1)+6.0*U(I,J)-4.0*U(I,J+1)+U(I,J+2))/
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1 DLY4
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RETURN
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C
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C COMPUTE PARTIAL DERIVATIVE APPROXIMATIONS AT Y=D-DLY
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C
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60 IF (KSWY .EQ. 1) GO TO 70
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UYYY = (U(I,L-4)-6.0*U(I,L-3)+12.0*U(I,L-2)-10.0*U(I,L-1)+
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1 3.0*U(I,L))/TDLY3
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UYYYY = (-U(I,L-5)+6.0*U(I,L-4)-14.0*U(I,L-3)+16.0*U(I,L-2)-
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1 9.0*U(I,L-1)+2.0*U(I,L))/DLY4
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RETURN
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C
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C PERIODIC AT Y=D-DLY
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C
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70 CONTINUE
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UYYY = (-U(I,L-3)+2.0*U(I,L-2)-2.0*U(I,1)+U(I,2))/TDLY3
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UYYYY = (U(I,L-3)-4.0*U(I,L-2)+6.0*U(I,L-1)-4.0*U(I,1)+U(I,2))/
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1 DLY4
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RETURN
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C
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C COMPUTE PARTIAL DERIVATIVE APPROXIMATIONS AT Y=D
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C
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80 UYYY = -(3.0*U(I,L-4)-14.0*U(I,L-3)+24.0*U(I,L-2)-18.0*U(I,L-1)+
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1 5.0*U(I,L))/TDLY3
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UYYYY = (-2.0*U(I,L-5)+11.0*U(I,L-4)-24.0*U(I,L-3)+26.0*U(I,L-2)-
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1 14.0*U(I,L-1)+3.0*U(I,L))/DLY4
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RETURN
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END
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