|
new file 100644
|
|
|
SUBROUTINE TRI3(M, vecA, vecB, vecC, ivecK, vecY1, vecY2, vecY3, TCOS, &
|
|
|
ITCOS, vecD, vecW1, vecW2, vecW3)
|
|
|
implicit none
|
|
|
|
|
|
DOUBLE PRECISION, PARAMETER :: ZERO = 0.0D0, HALF = 0.5D0, &
|
|
|
ONE = 1.0D0, TWO = 2.0D0, &
|
|
|
FOUR = 4.0D0
|
|
|
|
|
|
!-----------------------------------------------
|
|
|
! D u m m y A r g u m e n t s
|
|
|
!-----------------------------------------------
|
|
|
INTEGER, INTENT(IN) :: M,ITCOS
|
|
|
INTEGER, DIMENSION(4),INTENT(IN) :: ivecK
|
|
|
DOUBLE PRECISION, DIMENSION(M), INTENT(IN) :: vecA, vecB, vecC
|
|
|
DOUBLE PRECISION, DIMENSION(ITCOS), INTENT(IN) :: TCOS
|
|
|
DOUBLE PRECISION, DIMENSION(M), INTENT(INOUT) :: vecY1, vecY2, vecY3, &
|
|
|
vecD, vecW1, vecW2, vecW3
|
|
|
!-----------------------------------------------
|
|
|
! L o c a l V a r i a b l e s
|
|
|
!-----------------------------------------------
|
|
|
INTEGER :: MM1, K1, K2, K3, K4, IF1, IF2, IF3, IF4, K2K3K4, &
|
|
|
L1, L2, L3, LINT1, LINT2, LINT3, KINT1, KINT2, KINT3, &
|
|
|
N, I, IP
|
|
|
DOUBLE PRECISION :: X, Z, XX
|
|
|
!-----------------------------------------------
|
|
|
!
|
|
|
! SUBROUTINE TO SOLVE THREE LINEAR SYSTEMS WHOSE COMMON COEFFICIENT
|
|
|
! MATRIX IS A RATIONAL FUNCTION IN THE MATRIX GIVEN BY
|
|
|
!
|
|
|
! TRIDIAGONAL (...,vecA(I),vecB(I),vecC(I),...)
|
|
|
!
|
|
|
MM1 = M - 1
|
|
|
K1 = ivecK(1)
|
|
|
K2 = ivecK(2)
|
|
|
K3 = ivecK(3)
|
|
|
K4 = ivecK(4)
|
|
|
IF1 = K1 + 1
|
|
|
IF2 = K2 + 1
|
|
|
IF3 = K3 + 1
|
|
|
IF4 = K4 + 1
|
|
|
K2K3K4 = K2 + K3 + K4
|
|
|
IF (K2K3K4 /= 0) THEN
|
|
|
L1 = IF1/IF2
|
|
|
L2 = IF1/IF3
|
|
|
L3 = IF1/IF4
|
|
|
LINT1 = 1
|
|
|
LINT2 = 1
|
|
|
LINT3 = 1
|
|
|
KINT1 = K1
|
|
|
KINT2 = KINT1 + K2
|
|
|
KINT3 = KINT2 + K3
|
|
|
ELSE
|
|
|
write(*,*) 'warning', &
|
|
|
'tri3: l1,l2,l3,kint1,kint2,kint3 uninitialized'
|
|
|
stop 'stop in tri3: l1,l2,l3,kint1,kint2,kint3 uninitialized'
|
|
|
ENDIF
|
|
|
DO N = 1, K1
|
|
|
X = TCOS(N)
|
|
|
IF (K2K3K4 /= 0) THEN
|
|
|
IF (N == L1) THEN
|
|
|
vecW1(:M) = vecY1(:M)
|
|
|
ENDIF
|
|
|
IF (N == L2) THEN
|
|
|
vecW2(:M) = vecY2(:M)
|
|
|
ENDIF
|
|
|
IF (N == L3) THEN
|
|
|
vecW3(:M) = vecY3(:M)
|
|
|
ENDIF
|
|
|
ENDIF
|
|
|
Z = 1./(vecB(1)-X)
|
|
|
vecD(1) = vecC(1)*Z
|
|
|
vecY1(1) = vecY1(1)*Z
|
|
|
vecY2(1) = vecY2(1)*Z
|
|
|
vecY3(1) = vecY3(1)*Z
|
|
|
DO I = 2, M
|
|
|
Z = 1./(vecB(I)-X-vecA(I)*vecD(I-1))
|
|
|
vecD(I) = vecC(I)*Z
|
|
|
vecY1(I) = (vecY1(I)-vecA(I)*vecY1(I-1))*Z
|
|
|
vecY2(I) = (vecY2(I)-vecA(I)*vecY2(I-1))*Z
|
|
|
vecY3(I) = (vecY3(I)-vecA(I)*vecY3(I-1))*Z
|
|
|
END DO
|
|
|
DO IP = 1, MM1
|
|
|
vecY1(M-IP) = vecY1(M-IP) - vecD(M-IP)*vecY1(M+1-IP)
|
|
|
vecY2(M-IP) = vecY2(M-IP) - vecD(M-IP)*vecY2(M+1-IP)
|
|
|
vecY3(M-IP) = vecY3(M-IP) - vecD(M-IP)*vecY3(M+1-IP)
|
|
|
END DO
|
|
|
IF (K2K3K4 == 0) CYCLE
|
|
|
IF (N == L1) THEN
|
|
|
I = LINT1 + KINT1
|
|
|
XX = X - TCOS(I)
|
|
|
vecY1(:M) = XX*vecY1(:M) + vecW1(:M)
|
|
|
LINT1 = LINT1 + 1
|
|
|
L1 = (LINT1*IF1)/IF2
|
|
|
ENDIF
|
|
|
IF (N == L2) THEN
|
|
|
I = LINT2 + KINT2
|
|
|
XX = X - TCOS(I)
|
|
|
vecY2(:M) = XX*vecY2(:M) + vecW2(:M)
|
|
|
LINT2 = LINT2 + 1
|
|
|
L2 = (LINT2*IF1)/IF3
|
|
|
ENDIF
|
|
|
IF (N /= L3) CYCLE
|
|
|
I = LINT3 + KINT3
|
|
|
XX = X - TCOS(I)
|
|
|
vecY3(:M) = XX*vecY3(:M) + vecW3(:M)
|
|
|
LINT3 = LINT3 + 1
|
|
|
L3 = (LINT3*IF1)/IF4
|
|
|
END DO
|
|
|
RETURN
|
|
|
!
|
|
|
! REVISION HISTORY---
|
|
|
!
|
|
|
! SEPTEMBER 1973 VERSION 1
|
|
|
! APRIL 1976 VERSION 2
|
|
|
! JANUARY 1978 VERSION 3
|
|
|
! DECEMBER 1979 VERSION 3.1
|
|
|
! OCTOBER 1980 CHANGED SEVERAL DIVIDES OF FLOATING INTEGERS
|
|
|
! TO INTEGER DIVIDES TO ACCOMODATE CRAY-1 ARITHMETIC.
|
|
|
! FEBRUARY 1985 DOCUMENTATION UPGRADE
|
|
|
! NOVEMBER 1988 VERSION 3.2, FORTRAN 77 CHANGES
|
|
|
!-----------------------------------------------------------------------
|
|
|
END SUBROUTINE TRI3
|