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pywafo/wafo/source/rind2007/fimod.f

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Initial import of original WAFO code.
15 years ago
MODULE TRIVARIATEVAR
! Global variables used in calculation of TRIVARIATE
! normal and TRIVARIATE student T probabilties
INTEGER :: NU
DOUBLE PRECISION :: H1, H2, H3, R23, RUA, RUB, AR, RUC
END MODULE TRIVARIATEVAR
!
! FIMOD contains functions for calculating 1D, 2D and 3D Normal and student T probabilites
! and 1D expectations
move directory structure up, change root to: pywafo/src/* > wafo/*
9 years ago
MODULE FIMOD
Initial import of original WAFO code.
15 years ago
! USE ERFCOREMOD
IMPLICIT NONE
PRIVATE
PUBLIC :: NORMPRB, FI, FIINV, MVNLIMITS, MVNLMS, BVU,BVNMVN
PUBLIC :: GAUSINT, GAUSINT2, EXLMS, EXINV
PUBLIC :: STUDNT, BVTL, TVTL, TVNMVN
INTERFACE NORMPRB
MODULE PROCEDURE NORMPRB
END INTERFACE
INTERFACE FI
MODULE PROCEDURE FI
END INTERFACE
INTERFACE FI2
MODULE PROCEDURE FI2
END INTERFACE
INTERFACE FIINV
MODULE PROCEDURE FIINV
END INTERFACE
INTERFACE MVNLIMITS
MODULE PROCEDURE MVNLIMITS
END INTERFACE
INTERFACE MVNLMS
MODULE PROCEDURE MVNLMS
END INTERFACE
INTERFACE BVU
MODULE PROCEDURE BVU
END INTERFACE
INTERFACE BVNMVN
MODULE PROCEDURE BVNMVN
END INTERFACE
INTERFACE STUDNT
MODULE PROCEDURE STUDNT
END INTERFACE
INTERFACE BVTL
MODULE PROCEDURE BVTL
END INTERFACE
INTERFACE TVTL
MODULE PROCEDURE TVTL
END INTERFACE
INTERFACE GAUSINT
MODULE PROCEDURE GAUSINT
END INTERFACE
INTERFACE GAUSINT2
MODULE PROCEDURE GAUSINT2
END INTERFACE
INTERFACE EXLMS
MODULE PROCEDURE EXLMS
END INTERFACE
INTERFACE EXINV
MODULE PROCEDURE EXINV
END INTERFACE
CONTAINS
FUNCTION FIINV(P) RESULT (VAL)
IMPLICIT NONE
*
* ALGORITHM AS241 APPL. STATIST. (1988) VOL. 37, NO. 3
*
* Produces the normal deviate Z corresponding to a given lower
* tail area of P.
* Absolute error less than 1e-13
* Relative error less than 1e-15 for abs(VAL)>0.1
*
* The hash sums below are the sums of the mantissas of the
* coefficients. They are included for use in checking
* transcription.
*
DOUBLE PRECISION, INTENT(in) :: P
DOUBLE PRECISION :: VAL
!local variables
DOUBLE PRECISION SPLIT1, SPLIT2, CONST1, CONST2, ONE, ZERO, HALF,
& A0, A1, A2, A3, A4, A5, A6, A7, B1, B2, B3, B4, B5, B6, B7,
& C0, C1, C2, C3, C4, C5, C6, C7, D1, D2, D3, D4, D5, D6, D7,
& E0, E1, E2, E3, E4, E5, E6, E7, F1, F2, F3, F4, F5, F6, F7,
& Q, R
PARAMETER ( SPLIT1 = 0.425D0, SPLIT2 = 5.D0,
& CONST1 = 0.180625D0, CONST2 = 1.6D0,
& ONE = 1.D0, ZERO = 0.D0, HALF = 0.5D0 )
*
* Coefficients for P close to 0.5
*
PARAMETER (
* A0 = 3.38713 28727 96366 6080D0,
* A1 = 1.33141 66789 17843 7745D+2,
* A2 = 1.97159 09503 06551 4427D+3,
* A3 = 1.37316 93765 50946 1125D+4,
* A4 = 4.59219 53931 54987 1457D+4,
* A5 = 6.72657 70927 00870 0853D+4,
* A6 = 3.34305 75583 58812 8105D+4,
* A7 = 2.50908 09287 30122 6727D+3,
* B1 = 4.23133 30701 60091 1252D+1,
* B2 = 6.87187 00749 20579 0830D+2,
* B3 = 5.39419 60214 24751 1077D+3,
* B4 = 2.12137 94301 58659 5867D+4,
* B5 = 3.93078 95800 09271 0610D+4,
* B6 = 2.87290 85735 72194 2674D+4,
* B7 = 5.22649 52788 52854 5610D+3 )
* HASH SUM AB 55.88319 28806 14901 4439
*
* Coefficients for P not close to 0, 0.5 or 1.
*
PARAMETER (
* C0 = 1.42343 71107 49683 57734D0,
* C1 = 4.63033 78461 56545 29590D0,
* C2 = 5.76949 72214 60691 40550D0,
* C3 = 3.64784 83247 63204 60504D0,
* C4 = 1.27045 82524 52368 38258D0,
* C5 = 2.41780 72517 74506 11770D-1,
* C6 = 2.27238 44989 26918 45833D-2,
* C7 = 7.74545 01427 83414 07640D-4,
* D1 = 2.05319 16266 37758 82187D0,
* D2 = 1.67638 48301 83803 84940D0,
* D3 = 6.89767 33498 51000 04550D-1,
* D4 = 1.48103 97642 74800 74590D-1,
* D5 = 1.51986 66563 61645 71966D-2,
* D6 = 5.47593 80849 95344 94600D-4,
* D7 = 1.05075 00716 44416 84324D-9 )
* HASH SUM CD 49.33206 50330 16102 89036
*
* Coefficients for P near 0 or 1.
*
PARAMETER (
* E0 = 6.65790 46435 01103 77720D0,
* E1 = 5.46378 49111 64114 36990D0,
* E2 = 1.78482 65399 17291 33580D0,
* E3 = 2.96560 57182 85048 91230D-1,
* E4 = 2.65321 89526 57612 30930D-2,
* E5 = 1.24266 09473 88078 43860D-3,
* E6 = 2.71155 55687 43487 57815D-5,
* E7 = 2.01033 43992 92288 13265D-7,
* F1 = 5.99832 20655 58879 37690D-1,
* F2 = 1.36929 88092 27358 05310D-1,
* F3 = 1.48753 61290 85061 48525D-2,
* F4 = 7.86869 13114 56132 59100D-4,
* F5 = 1.84631 83175 10054 68180D-5,
* F6 = 1.42151 17583 16445 88870D-7,
* F7 = 2.04426 31033 89939 78564D-15 )
* HASH SUM EF 47.52583 31754 92896 71629
*
Q = ( P - HALF)
IF ( ABS(Q) .LE. SPLIT1 ) THEN ! Central range.
R = CONST1 - Q*Q
VAL = Q*( ( ( ((((A7*R + A6)*R + A5)*R + A4)*R + A3)
* *R + A2 )*R + A1 )*R + A0 )
* /( ( ( ((((B7*R + B6)*R + B5)*R + B4)*R + B3)
* *R + B2 )*R + B1 )*R + ONE)
ELSE ! near the endpoints
R = MIN( P, ONE - P )
IF (R .GT.ZERO) THEN ! ( 2.d0*R .GT. CFxCutOff) THEN ! R .GT.0.d0
R = SQRT( -LOG(R) )
IF ( R .LE. SPLIT2 ) THEN
R = R - CONST2
VAL = ( ( ( ((((C7*R + C6)*R + C5)*R + C4)*R + C3)
* *R + C2 )*R + C1 )*R + C0 )
* /( ( ( ((((D7*R + D6)*R + D5)*R + D4)*R + D3)
* *R + D2 )*R + D1 )*R + ONE )
ELSE
R = R - SPLIT2
VAL = ( ( ( ((((E7*R + E6)*R + E5)*R + E4)*R + E3)
* *R + E2 )*R + E1 )*R + E0 )
* /( ( ( ((((F7*R + F6)*R + F5)*R + F4)*R + F3)
* *R + F2 )*R + F1 )*R + ONE )
END IF
ELSE
VAL = 37.0d0 !9.D0 !XMAX 9.d0
END IF
IF ( Q < ZERO ) VAL = - VAL
END IF
RETURN
END FUNCTION FIINV
! *********************************
SUBROUTINE NORMPRB(Z, P, Q)
! USE ERFCOREMOD
! USE GLOBALDATA, ONLY : XMAX
! Normal distribution probabilities accurate to 18 digits between
! -XMAX and XMAX
!
! Z = no. of standard deviations from the mean.
! P, Q = probabilities to the left & right of Z. P + Q = 1.
!
! by pab 23.03.2003
!
IMPLICIT NONE
DOUBLE PRECISION, INTENT(IN) :: Z
DOUBLE PRECISION, INTENT(OUT) :: P
DOUBLE PRECISION, INTENT(OUT), OPTIONAL :: Q
!Local variables
DOUBLE PRECISION :: PP, ZABS
DOUBLE PRECISION, PARAMETER :: ZERO = 0.0D0
DOUBLE PRECISION, PARAMETER :: ONE = 1.0D0
DOUBLE PRECISION, PARAMETER :: SQ2M1 = 0.70710678118655D0 ! 1/SQRT(2)
DOUBLE PRECISION, PARAMETER :: HALF = 0.5D0
DOUBLE PRECISION, PARAMETER :: XMAX = 37D0
ZABS = ABS(Z)
!
! |Z| > 37 (or XMAX)
!
IF ( ZABS .GT. XMAX ) THEN
IF (Z > ZERO) THEN
P = ONE
IF (PRESENT(Q)) Q = ZERO
ELSE
P = ZERO
IF (PRESENT(Q)) Q = ONE
END IF
ELSE
!
! |Z| <= 37
!
PP = DERFC(ZABS*SQ2M1)*HALF
IF (Z < ZERO) THEN
P = PP
IF (PRESENT(Q)) Q = ONE - PP
ELSE
P = ONE - PP
IF (PRESENT(Q)) Q = PP
END IF
END IF
RETURN
END SUBROUTINE NORMPRB
FUNCTION FI( Z ) RESULT (VALUE)
! USE ERFCOREMOD
! USE GLOBALDATA, ONLY : XMAX
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: Z
DOUBLE PRECISION :: VALUE
! Local variables
DOUBLE PRECISION :: ZABS
DOUBLE PRECISION, PARAMETER:: SQ2M1 = 0.70710678118655D0 ! 1/SQRT(2)
DOUBLE PRECISION, PARAMETER:: HALF = 0.5D0
DOUBLE PRECISION, PARAMETER:: XMAX = 37.D0
ZABS = ABS(Z)
*
* |Z| > 37 (or XMAX)
*
IF ( ZABS .GT. XMAX ) THEN
IF (Z < 0.0D0) THEN
VALUE = 0.0D0
ELSE
VALUE = 1.0D0
ENDIF
ELSE
VALUE = DERFC(-Z*SQ2M1)*HALF
ENDIF
RETURN
END FUNCTION FI
FUNCTION FI2( Z ) RESULT (VALUE)
! USE GLOBALDATA, ONLY : XMAX
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: Z
DOUBLE PRECISION :: VALUE
*
* Normal distribution probabilities accurate to 1.e-15.
* relative error less than 1e-8;
* Z = no. of standard deviations from the mean.
*
* Based upon algorithm 5666 for the error function, from:
* Hart, J.F. et al, 'Computer Approximations', Wiley 1968
*
* Programmer: Alan Miller
*
* Latest revision - 30 March 1986
*
DOUBLE PRECISION :: P0, P1, P2, P3, P4, P5, P6,
* Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7,XMAX,
* P, EXPNTL, CUTOFF, ROOTPI, ZABS, Z2
PARAMETER(
* P0 = 220.20 68679 12376 1D0,
* P1 = 221.21 35961 69931 1D0,
* P2 = 112.07 92914 97870 9D0,
* P3 = 33.912 86607 83830 0D0,
* P4 = 6.3739 62203 53165 0D0,
* P5 = 0.70038 30644 43688 1D0,
* P6 = 0.035262 49659 98910 9D0 )
PARAMETER(
* Q0 = 440.41 37358 24752 2D0,
* Q1 = 793.82 65125 19948 4D0,
* Q2 = 637.33 36333 78831 1D0,
* Q3 = 296.56 42487 79673 7D0,
* Q4 = 86.780 73220 29460 8D0,
* Q5 = 16.064 17757 92069 5D0,
* Q6 = 1.7556 67163 18264 2D0,
* Q7 = 0.088388 34764 83184 4D0 )
PARAMETER( ROOTPI = 2.5066 28274 63100 1D0 )
PARAMETER( CUTOFF = 7.0710 67811 86547 5D0 )
PARAMETER( XMAX = 37.D0 )
*
ZABS = ABS(Z)
*
* |Z| > 37 (or XMAX)
*
IF ( ZABS .GT. XMAX ) THEN
P = 0.d0
ELSE
*
* |Z| <= 37
*
Z2 = ZABS * ZABS
EXPNTL = EXP( -Z2 * 0.5D0 )
*
* |Z| < CUTOFF = 10/SQRT(2)
*
IF ( ZABS < CUTOFF ) THEN
P = EXPNTL*( (((((P6*ZABS + P5)*ZABS + P4)*ZABS + P3)*ZABS
* + P2)*ZABS + P1)*ZABS + P0)/(((((((Q7*ZABS + Q6)*ZABS
* + Q5)*ZABS + Q4)*ZABS + Q3)*ZABS + Q2)*ZABS + Q1)*ZABS
* + Q0 )
*
* |Z| >= CUTOFF.
*
ELSE
P = EXPNTL/( ZABS + 1.d0/( ZABS + 2.d0/( ZABS + 3.d0/( ZABS
* + 4.d0/( ZABS + 0.65D0 ) ) ) ) )/ROOTPI
END IF
END IF
IF ( Z .GT. 0.d0 ) P = 1.d0 - P
VALUE = P
RETURN
END FUNCTION FI2
SUBROUTINE MVNLIMITS( A, B, INFIN, AP, PRB, AQ)
! RETURN probabilities for being between A and B
! WHERE
! AP = FI(A), AQ = 1 - FI(A)
! BP = FI(B), BQ = 1 - FI(B)
! PRB = BP-AP IF BP+AP<1
! = AQ-BQ OTHERWISE
!
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: A, B
DOUBLE PRECISION, INTENT(out) :: AP
DOUBLE PRECISION, INTENT(out),OPTIONAL :: PRB,AQ
INTEGER,INTENT(in) :: INFIN
! LOCAL VARIABLES
DOUBLE PRECISION :: BP,AQQ, BQQ
DOUBLE PRECISION, PARAMETER :: ONE=1.D0, ZERO = 0.D0
SELECT CASE (infin)
CASE (:-1)
AP = ZERO
! BP = ONE
IF (PRESENT(PRB)) PRB = ONE
IF (PRESENT(AQ)) AQ = ONE
! IF (PRESENT(BQ)) BQ = ZERO
CASE (0)
AP = ZERO
CALL NORMPRB(B,BP) !,BQQ)
IF (PRESENT(PRB)) PRB = BP
IF (PRESENT(AQ)) AQ = ONE
! IF (PRESENT(BQ)) BQ = BQQ
CASE (1)
! BP = ONE
CALL NORMPRB(A,AP,AQQ)
IF (PRESENT(PRB)) PRB = AQQ
IF (PRESENT(AQ)) AQ = AQQ
! IF (PRESENT(BQ)) BQ = ZERO
CASE (2:)
CALL NORMPRB(A,AP,AQQ)
CALL NORMPRB(B,BP,BQQ)
IF (PRESENT(PRB)) THEN
IF (AP+BP < ONE) THEN
PRB = BP - AP
ELSE
PRB = AQQ - BQQ
END IF
ENDIF
IF (PRESENT(AQ)) AQ = AQQ
! IF (PRESENT(BQ)) BQ = BQQ
END SELECT
RETURN
END SUBROUTINE MVNLIMITS
SUBROUTINE MVNLMS( A, B, INFIN, LOWER, UPPER )
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: A, B
DOUBLE PRECISION, INTENT(out) :: LOWER, UPPER
INTEGER,INTENT(in) :: INFIN
LOWER = 0.0D0
UPPER = 1.0D0
IF ( INFIN < 0 ) RETURN
IF ( INFIN .NE. 0 ) LOWER = FI(A)
IF ( INFIN .NE. 1 ) UPPER = FI(B)
RETURN
END SUBROUTINE MVNLMS
FUNCTION TVNMVN(A, B, INFIN, R, EPSI ) RESULT (VAL)
IMPLICIT NONE
*
* A function for computing trivariate normal probabilities.
*
* Parameters
*
* A REAL, array of lower integration limits.
* B REAL, array of upper integration limits.
! R REAL, array of correlation coefficents
! R = [r12 r13 r23]
! EPSI = REAL tolerance
* INFIN INTEGER, array of integration limits flags:
* if INFIN(I) = 0, Ith limits are (-infinity, B(I)];
* if INFIN(I) = 1, Ith limits are [A(I), infinity);
* if INFIN(I) = 2, Ith limits are [A(I), B(I)].
DOUBLE PRECISION, DIMENSION(:), INTENT (IN) :: A, B , R
DOUBLE PRECISION, INTENT (IN) :: EPSI
INTEGER, DIMENSION(:), INTENT (IN) :: INFIN
DOUBLE PRECISION :: VAL
IF ( INFIN(1) .EQ. 2 ) THEN
IF ( INFIN(2) .EQ. 2 ) THEN
IF (INFIN(3) .EQ. 2 ) THEN !OK
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( A(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( B(1), A(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( B(1), B(2), A(3),R(1),R(2),R(3),EPSI )
& + TVNL( A(1), A(2), B(3),R(1),R(2),R(3),EPSI )
& + TVNL( A(1), B(2), A(3),R(1),R(2),R(3),EPSI )
$ + TVNL( B(1), A(2), A(3),R(1),R(2),R(3),EPSI )
& - TVNL( A(1), A(2), A(3),R(1),R(2),R(3),EPSI )
ELSE IF (INFIN(3) .EQ. 1 ) THEN ! B(3) = inf ok
VAL = TVNL( B(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI )
& - TVNL( A(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI )
& - TVNL( B(1), A(2), -A(3),R(1),-R(2),-R(3),EPSI )
& + TVNL( A(1), A(2), -A(3),R(1),-R(2),-R(3),EPSI )
ELSE IF (INFIN(3) .EQ. 0 ) THEN !OK A(3) = -inf
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( A(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( B(1), A(2), B(3),R(1),R(2),R(3),EPSI )
& + TVNL( A(1), A(2), B(3),R(1),R(2),R(3),EPSI )
ELSE ! INFIN(1:2)=2
VAL = BVNMVN( A ,B, INFIN, R(1) )
ENDIF
ELSE IF (INFIN(2) .EQ. 1 ) THEN ! B(2) = inf
IF (INFIN(3) .EQ. 2 ) THEN
VAL = TVNL( B(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI )
& - TVNL( A(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI )
& - TVNL( B(1), -A(2), A(3),-R(1),R(2),-R(3),EPSI )
& + TVNL( A(1), -A(2), A(3),-R(1),R(2),-R(3),EPSI )
ELSE IF (INFIN(3) .EQ. 1 ) THEN
VAL = TVNL( B(1), -A(2), -A(3),-R(1),-R(2),R(3),EPSI )
$ - TVNL( A(1), -A(2), -A(3),-R(1),-R(2),R(3),EPSI )
ELSE IF (INFIN(3) .EQ. 0 ) THEN
VAL = TVNL( B(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI)
$ - TVNL( A(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI)
ELSE
VAL = BVNMVN( A ,B, INFIN, R(1) )
ENDIF
ELSE IF (INFIN(2) .EQ. 0 ) THEN
SELECT CASE (INFIN(3))
CASE (2:) ! % % A(2)=-INF
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
$ - TVNL( A(1), B(2), B(3),R(1),R(2),R(3),EPSI )
$ - TVNL( B(1), B(2), A(3),R(1),R(2),R(3),EPSI )
$ + TVNL( A(1), B(2), A(3),R(1),R(2),R(3),EPSI )
CASE (1) !% % A(2)=-INF B(3) = INF
VAL = TVNL( B(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI)
$ - TVNL(A(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI)
CASE (0) ! % % A(2)=-INF A(3) = -INF
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
$ - TVNL( A(1), B(2), B(3),R(1),R(2),R(3),EPSI)
CASE DEFAULT
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
ELSE
VAL = BVNMVN(A(1:3:2),B(1:3:2),INFIN(1:3:2),R(2))
ENDIF
ELSE IF ( INFIN(1) .EQ. 1 ) THEN
SELECT CASE (INFIN(2))
CASE (2)
SELECT CASE (INFIN(3))
CASE (2) !% B(1) = INF %OK
VAL = TVNL(-A(1), B(2), B(3),-R(1),-R(2),R(3),EPSI )
$ - TVNL(-A(1), B(2), A(3),-R(1),-R(2),R(3),EPSI )
$ - TVNL(-A(1), A(2), B(3),-R(1),-R(2),R(3),EPSI )
$ + TVNL(-A(1), A(2), A(3),-R(1),-R(2),R(3),EPSI )
CASE (1) ! % B(1) = INF B(3) = INF %OK
VAL = TVNL(-A(1), B(2), -A(3),-R(1),R(2),-R(3),EPSI )
$ - TVNL(-A(1), A(2), -A(3),-R(1),R(2),-R(3),EPSI)
CASE (0) ! % B(1) = INF A(3) = -INF %OK
VAL = TVNL(-A(1), B(2), B(3),-R(1),-R(2),R(3),EPSI )
$ - TVNL(-A(1), A(2), B(3),-R(1),-R(2),R(3),EPSI)
CASE (-1)
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE (1) !%B(2) = INF
SELECT CASE (INFIN(3))
CASE (2) ! % B(1) = INF B(2) = INF % OK
VAL = TVNL( -A(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI )
& - TVNL( -A(1), -A(2),A(3),-R(1),R(2),-R(3),EPSI )
CASE (1) ! % B(1:3) = INF %OK
VAL = TVNL( -A(1), -A(2), -A(3),R(1),R(2),R(3),EPSI)
CASE (0) ! % B(1:2) = INF A(3) = -INF %OK
VAL = TVNL( -A(1), -A(2), B(3),R(1),-R(2),-R(3),EPSI )
CASE (:-1)
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE (0) ! A(2) = -INF
SELECT CASE ( INFIN(3))
CASE (2) ! B(1) = INF , A(2) = -INF %OK
VAL = TVNL( -A(1), B(2), B(3),-R(1),R(2),-R(3),EPSI )
& - TVNL( -A(1), B(2),A(3),-R(1),R(2),-R(3),EPSI )
CASE (1) ! B(1) = INF , A(2) = -INF B(3) = INF % OK
VAL = TVNL( -A(1), B(2), -A(3),-R(1),-R(2),R(3),EPSI)
CASE (0) !% B(1) = INF , A(2:3) = -INF
VAL = TVNL( -A(1), B(2), B(3),-R(1),-R(2),R(3),EPSI )
CASE (:-1)
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE DEFAULT
VAL = BVNMVN(A(1:3:2),B(1:3:2),INFIN(1:3:2),R(2))
END SELECT
ELSE IF ( INFIN(1) .EQ. 0 ) THEN
SELECT CASE (INFIN(2))
CASE (2)
SELECT CASE (INFIN(3))
CASE (2:) ! A(1) = -INF %OK
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( B(1), B(2), A(3),R(1),R(2),R(3),EPSI)
& - TVNL( B(1), A(2), B(3),R(1),R(2),R(3),EPSI )
& + TVNL( B(1), A(2), A(3),R(1),R(2),R(3),EPSI )
CASE (1) ! % A(1) = -INF , B(3) = INF %OK
VAL = TVNL( B(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI )
$ - TVNL( B(1), A(2), -A(3),R(1),-R(2),-R(3),EPSI )
CASE (0) ! A(1) = -INF , A(3) = -INF %OK
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
& - TVNL( B(1), A(2), B(3),R(1),R(2),R(3),EPSI )
CASE DEFAULT
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE (1) ! B(2) = INF
SELECT CASE (INFIN(3))
CASE (2:) ! A(1) = -INF B(2) = INF %OK
VAL = TVNL( B(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI)
$ - TVNL( B(1), -A(2), A(3),-R(1),R(2),-R(3),EPSI)
CASE (1) ! A(1) = -INF B(2) = INF B(3) = INF %OK
VAL = TVNL( B(1), -A(2), -A(3),-R(1),-R(2),R(3),EPSI)
CASE (0) ! % A(1) = -INF B(2) = INF A(3) = -INF %OK
VAL = TVNL(B(1), -A(2), B(3),-R(1),R(2),-R(3),EPSI)
CASE DEFAULT
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE (0) ! A(2) = -INF
SELECT CASE (INFIN(3))
CASE (2:) ! % A(1:2) = -INF
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI)
$ - TVNL( B(1), B(2), A(3),R(1),R(2),R(3),EPSI)
CASE (1) ! A(1:2) = -INF B(3) = INF
VAL = TVNL( B(1), B(2), -A(3),R(1),-R(2),-R(3),EPSI)
CASE (0) ! % A(1:3) = -INF
VAL = TVNL( B(1), B(2), B(3),R(1),R(2),R(3),EPSI )
CASE DEFAULT
VAL = BVNMVN(A,B,INFIN,R(1))
END SELECT
CASE DEFAULT
VAL = BVNMVN(A(1:3:2),B(1:3:2),INFIN(1:3:2),R(2))
END SELECT
ELSE
VAL = BVNMVN(A(2:3),B(2:3),INFIN(2:3),R(3))
END IF
CONTAINS
DOUBLE PRECISION FUNCTION TVNL(H1,H2,H3, R12,R13,R23, EPSI )
!Returns Trivariate Normal CDF
DOUBLE PRECISION, INTENT(IN) :: R12,R13,R23
DOUBLE PRECISION, INTENT(IN) :: H1,H2,H3, EPSI
! Locals
INTEGER, PARAMETER :: NU = 0
DOUBLE PRECISION,DIMENSION(3) :: H,R
H(:) = (/ H1, H2, H3 /)
R(:) = (/ R12, R13, R23 /)
TVNL = TVTL(NU,H,R,EPSI)
END FUNCTION TVNL
END FUNCTION TVNMVN
FUNCTION BVNMVN( LOWER, UPPER, INFIN, CORREL ) RESULT (VAL)
IMPLICIT NONE
*
* A function for computing bivariate normal probabilities.
*
* Parameters
*
* LOWER REAL, array of lower integration limits.
* UPPER REAL, array of upper integration limits.
* INFIN INTEGER, array of integration limits flags:
* if INFIN(I) = 0, Ith limits are (-infinity, UPPER(I)];
* if INFIN(I) = 1, Ith limits are [LOWER(I), infinity);
* if INFIN(I) = 2, Ith limits are [LOWER(I), UPPER(I)].
* CORREL REAL, correlation coefficient.
*
DOUBLE PRECISION, DIMENSION(:), INTENT (IN) :: LOWER, UPPER
DOUBLE PRECISION, INTENT (IN) :: CORREL
INTEGER, DIMENSION(:), INTENT (IN) :: INFIN
DOUBLE PRECISION :: VAL
DOUBLE PRECISION :: E
SELECT CASE (INFIN(1))
CASE (2:)
SELECT CASE ( INFIN(2) )
CASE (2:)
VAL = BVU ( LOWER(1), LOWER(2), CORREL )
& - BVU ( UPPER(1), LOWER(2), CORREL )
& - BVU ( LOWER(1), UPPER(2), CORREL )
& + BVU ( UPPER(1), UPPER(2), CORREL )
CASE (1)
VAL = BVU ( LOWER(1), LOWER(2), CORREL )
& - BVU ( UPPER(1), LOWER(2), CORREL )
CASE (0)
VAL = BVU ( -UPPER(1), -UPPER(2), CORREL )
& - BVU ( -LOWER(1), -UPPER(2), CORREL )
CASE DEFAULT
CALL MVNLIMITS(LOWER(1),UPPER(1),INFIN(1),E,VAL)
END SELECT
CASE (1)
SELECT CASE ( INFIN(2))
CASE ( 2: )
VAL = BVU ( LOWER(1), LOWER(2), CORREL )
& - BVU ( LOWER(1), UPPER(2), CORREL )
CASE (1)
VAL = BVU ( LOWER(1), LOWER(2), CORREL )
CASE (0)
VAL = BVU ( LOWER(1), -UPPER(2), -CORREL )
CASE DEFAULT
CALL MVNLIMITS(LOWER(2),UPPER(2),INFIN(2),E,VAL)
END SELECT
CASE (0)
SELECT CASE ( INFIN(2))
CASE ( 2: )
VAL = BVU ( -UPPER(1), -UPPER(2), CORREL )
& - BVU ( -UPPER(1), -LOWER(2), CORREL )
CASE ( 1 )
VAL = BVU ( -UPPER(1), LOWER(2), -CORREL )
CASE (0)
VAL = BVU ( -UPPER(1), -UPPER(2), CORREL )
CASE DEFAULT
CALL MVNLIMITS(LOWER(1),UPPER(1),INFIN(1),E,VAL)
END SELECT
CASE DEFAULT !ELSE !INFIN(1)<0
CALL MVNLIMITS(LOWER(2),UPPER(2),INFIN(2),E,VAL)
END SELECT
END FUNCTION BVNMVN
FUNCTION BVU( SH, SK, R ) RESULT (VAL)
! USE GLOBALDATA, ONLY: XMAX
IMPLICIT NONE
*
! A function for computing bivariate normal probabilities.
!
! Yihong Ge
! Department of Computer Science and Electrical Engineering
! Washington State University
! Pullman, WA 99164-2752
! and
! Alan Genz
! Department of Mathematics
! Washington State University
! Pullman, WA 99164-3113
! Email : alangenz@wsu.edu
!
! This function is based on the method described by
! Drezner, Z and G.O. Wesolowsky, (1989),
! On the computation of the bivariate normal integral,
! Journal of Statist. Comput. Simul. 35, pp. 101-107,
! with major modifications for double precision, and for |R| close to 1.
!
! BVU - calculate the probability that X > SH and Y > SK.
! (to accuracy of 1e-16?)
!
! Parameters
!
! SH REAL, lower integration limit
! SK REAL, lower integration limit
! R REAL, correlation coefficient
!
! LG INTEGER, number of Gauss Rule Points and Weights
!
! Revised pab added check on XMAX
DOUBLE PRECISION, INTENT(IN) :: SH, SK, R
DOUBLE PRECISION :: VAL
! Local variables
DOUBLE PRECISION :: ZERO,ONE,FOUR
DOUBLE PRECISION :: SQTWOPI ,TWOPI1,FOURPI1
DOUBLE PRECISION :: HALF,ONETHIRD,ONEEIGHT,ONESIXTEEN
DOUBLE PRECISION :: TWELVE, EXPMIN, XMAX
INTEGER :: I, LG, NG
PARAMETER ( ZERO = 0.D0,ONE=1.0D0,HALF=0.5D0)
PARAMETER (FOUR = 4.0D0, TWELVE = 12.0D0)
PARAMETER (EXPMIN = -100.0D0)
PARAMETER (ONESIXTEEN = 0.0625D0) !1/16
PARAMETER (ONEEIGHT = 0.125D0 ) !1/8
PARAMETER (ONETHIRD = 0.3333333333333333333333D0)
! PARAMETER (TWOPI = 6.283185307179586D0 )
PARAMETER (TWOPI1 = 0.15915494309190D0 ) !1/(2*pi)
PARAMETER (FOURPI1 = 0.0795774715459476D0 ) !/1/(4*pi)
PARAMETER (SQTWOPI = 2.50662827463100D0) ! SQRT(2*pi)
PARAMETER (XMAX = 8.3D0)
DOUBLE PRECISION, DIMENSION(10,3) :: X, W
DOUBLE PRECISION :: AS, A, B, C, D, RS, XS
DOUBLE PRECISION :: SN, ASR, H, K, BS, HS, HK
! Gauss Legendre Points and Weights, N = 6
DATA ( W(I,1), X(I,1), I = 1,3) /
* 0.1713244923791705D+00,-0.9324695142031522D+00,
* 0.3607615730481384D+00,-0.6612093864662647D+00,
* 0.4679139345726904D+00,-0.2386191860831970D+00/
! Gauss Legendre Points and Weights, N = 12
DATA ( W(I,2), X(I,2), I = 1,6) /
* 0.4717533638651177D-01,-0.9815606342467191D+00,
* 0.1069393259953183D+00,-0.9041172563704750D+00,
* 0.1600783285433464D+00,-0.7699026741943050D+00,
* 0.2031674267230659D+00,-0.5873179542866171D+00,
* 0.2334925365383547D+00,-0.3678314989981802D+00,
* 0.2491470458134029D+00,-0.1252334085114692D+00/
! Gauss Legendre Points and Weights, N = 20
DATA ( W(I,3), X(I,3), I = 1,10) /
* 0.1761400713915212D-01,-0.9931285991850949D+00,
* 0.4060142980038694D-01,-0.9639719272779138D+00,
* 0.6267204833410906D-01,-0.9122344282513259D+00,
* 0.8327674157670475D-01,-0.8391169718222188D+00,
* 0.1019301198172404D+00,-0.7463319064601508D+00,
* 0.1181945319615184D+00,-0.6360536807265150D+00,
* 0.1316886384491766D+00,-0.5108670019508271D+00,
* 0.1420961093183821D+00,-0.3737060887154196D+00,
* 0.1491729864726037D+00,-0.2277858511416451D+00,
* 0.1527533871307259D+00,-0.7652652113349733D-01/
SAVE W, X
VAL = ZERO
HK = MIN(SH,SK)
IF ( HK < -XMAX) THEN ! pab 24.05.2003
VAL = FI(-MAX(SH,SK))
RETURN
ELSE IF ( XMAX < MAX(SH,SK)) THEN
RETURN
ENDIF
IF ( ABS(R) < 0.3D0 ) THEN
NG = 1
LG = 3
ELSE IF ( ABS(R) < 0.75D0 ) THEN
NG = 2
LG = 6
ELSE
NG = 3
LG = 10
ENDIF
H = SH
K = SK
HK = H*K
IF ( ABS(R) < 0.925D0 ) THEN
IF (ABS(R) .GT. ZERO ) THEN
HS = ( H*H + K*K )*HALF
ASR = ASIN(R)
DO I = 1, LG
SN = SIN(ASR*(ONE + X(I,NG))*HALF)
VAL = VAL + W(I,NG)*EXP( ( SN*HK - HS )/( ONE - SN*SN ) )
SN = SIN(ASR*(ONE - X(I,NG))*HALF)
VAL = VAL + W(I,NG)*EXP( ( SN*HK - HS )/( ONE - SN*SN ) )
END DO
VAL = VAL*ASR*FOURPI1
ENDIF
VAL = VAL + FI(-H)*FI(-K)
ELSE
IF ( R < ZERO ) THEN
K = -K
HK = -HK
ENDIF
IF ( ABS(R) < ONE ) THEN
AS = ( ONE - R )*( ONE + R )
A = SQRT(AS)
B = ABS( H - K ) !**2
BS = B * B
C = ( FOUR - HK ) * ONEEIGHT !/8D0
D = ( TWELVE - HK ) * ONESIXTEEN !/16D0
ASR = -(BS/AS + HK)*HALF
IF (ASR.GT.EXPMIN) THEN
VAL = A*EXP( ASR ) *
& ( ONE - C*(BS - AS)*(ONE - D*BS*0.2D0)*ONETHIRD +
& C*D*AS*AS*0.2D0 )
ENDIF
IF ( HK .GT. EXPMIN ) THEN
VAL = VAL - EXP(-HK*HALF)*SQTWOPI*FI(-B/A)*B
+ *( ONE - C*BS*( ONE - D*BS*0.2D0 )*ONETHIRD )
ENDIF
A = A * HALF
DO I = 1, LG
XS = ( A * (ONE + X(I,NG)) ) !**2
XS = XS * XS
RS = SQRT( ONE - XS )
ASR = -(BS / XS + HK) * HALF
IF (ASR.GT.EXPMIN) THEN
VAL = VAL + A*W(I,NG)*EXP( ASR )
& * ( EXP( - HALF*HK*( ONE - RS )/( ONE + RS ) )/RS
$ -( ONE + C*XS*( ONE + D*XS ) ) )
ENDIF
XS = ( A * (ONE - X(I,NG)) ) !**2
XS = XS * XS
RS = SQRT( ONE - XS )
ASR = -(BS / XS + HK) * HALF
IF (ASR.GT.EXPMIN) THEN
VAL = VAL + A*W(I,NG)*EXP( ASR )
& *( EXP( - HALF*HK*( ONE - RS )/( ONE + RS ) )/RS-
$ ( ONE + C*XS*( ONE + D*XS ) ) )
ENDIF
END DO
VAL = -VAL*TWOPI1
ENDIF
IF ( R .GT. ZERO ) THEN
VAL = VAL + FI( -MAX( H, K ) )
ELSE
VAL = -VAL
IF ( H < K ) VAL = VAL + FI(K)-FI(H)
ENDIF
ENDIF
RETURN
END FUNCTION BVU
DOUBLE PRECISION FUNCTION STUDNT( NU, T )
IMPLICIT NONE
!
! Student t Distribution Function
!
! T
! STUDNT = C I ( 1 + y*y/NU )**( -(NU+1)/2 ) dy
! NU -INF
!
INTEGER, INTENT(IN) :: NU
DOUBLE PRECISION, INTENT(IN) :: T
! Locals
INTEGER :: J
DOUBLE PRECISION :: ZRO, ONE
PARAMETER ( ZRO = 0.0D0, ONE = 1.0D0 )
DOUBLE PRECISION, PARAMETER :: PI = 3.14159265358979D0
DOUBLE PRECISION :: CSSTHE, SNTHE, POLYN, TT, TS, RN
IF ( NU < 1 ) THEN
STUDNT = FI( T )
ELSE IF ( NU .EQ. 1 ) THEN
STUDNT = ( ONE + 2.0D0*ATAN(T)/PI )*0.5D0
ELSE IF ( NU .EQ. 2 ) THEN
STUDNT = ( ONE + T/SQRT( 2.0D0 + T*T ))*0.5D0
ELSE
RN = NU ! convert to double
TT = T * T
CSSTHE = ONE/( ONE + TT/RN )
POLYN = 1
DO J = NU-2, 2, -2
POLYN = ONE + ( J - 1 )*CSSTHE*POLYN/J
END DO
IF ( MOD( NU, 2 ) .EQ. 1 ) THEN
TS = T/SQRT(RN)
STUDNT = ( ONE + 2.0D0*( ATAN(TS) +
& TS*CSSTHE*POLYN )/PI )*0.5D0
ELSE
SNTHE = T/SQRT( RN + TT )
STUDNT = ( ONE + SNTHE*POLYN )*0.5D0
END IF
STUDNT = MAX( ZRO, MIN( STUDNT, ONE ) )
ENDIF
END FUNCTION STUDNT
DOUBLE PRECISION FUNCTION BVTL( NU, DH, DK, R )
IMPLICIT NONE
!*
!* A function for computing bivariate t probabilities.
!*
!* Alan Genz
!* Department of Mathematics
!* Washington State University
!* Pullman, WA 99164-3113
!* Email : alangenz@wsu.edu
!*
!* This function is based on the method described by
!* Dunnett, C.W. and M. Sobel, (1954),
!* A bivariate generalization of Student's t-distribution
!* with tables for certain special cases,
!* Biometrika 41, pp. 153-169.
!*
!* BVTL - calculate the probability that X < DH and Y < DK.
!*
!* parameters
!*
!* NU number of degrees of freedom (NOTE: NU = 0 gives bivariate normal prb)
!* DH 1st lower integration limit
!* DK 2nd lower integration limit
!* R correlation coefficient
!*
INTEGER, INTENT(IN) ::NU
DOUBLE PRECISION, INTENT(IN) :: DH, DK, R
! Locals
INTEGER :: J, HS, KS
DOUBLE PRECISION :: ORS, HRK, KRH, BVT
DOUBLE PRECISION :: DH2, DK2, SNU ,DNU, DHDK
!, BVND, STUDNT
DOUBLE PRECISION :: GMPH, GMPK, XNKH, XNHK, QHRK, HKN, HPK, HKRN
DOUBLE PRECISION :: BTNCKH, BTNCHK, BTPDKH, BTPDHK
DOUBLE PRECISION :: ZERO, ONE, EPS, PI,TPI
PARAMETER ( ZERO = 0.0D0, ONE = 1.0D0, EPS = 1.0D-15 )
PARAMETER (PI = 3.14159265358979D0, TPI = 6.28318530717959D0)
IF ( NU < 1 ) THEN
BVTL = BVU( -DH, -DK, R )
ELSE IF ( ONE - R .LE. EPS .OR. 1.0D+16<MAX(ABS(DH),ABS(DK))) THEN
BVTL = STUDNT( NU, MIN( DH, DK ) )
ELSE IF ( R + ONE .LE. EPS ) THEN
IF ( DH .GT. -DK ) THEN
BVTL = STUDNT( NU, DH ) - STUDNT( NU, -DK )
ELSE
BVTL = ZERO
END IF
ELSE
!PI = ACOS(-ONE)
!TPI = 2*PI
DNU = NU ! convert to double
SNU = SQRT(DNU)
ORS = ONE - R * R
HRK = DH - R * DK
KRH = DK - R * DH
DK2 = DK * DK
DH2 = DH * DH
IF ( ABS(HRK) + ORS .GT. ZERO ) THEN
XNHK = HRK**2/( HRK**2 + ORS*( DNU + DK2 ) )
XNKH = KRH**2/( KRH**2 + ORS*( DNU + DH2 ) )
ELSE
XNHK = ZERO
XNKH = ZERO
END IF
HS = INT(DSIGN( ONE, HRK)) !DH - R*DK )
KS = INT(DSIGN( ONE, KRH)) !DK - R*DH )
IF ( MOD( NU, 2 ) .EQ. 0 ) THEN
BVT = ATAN2( SQRT(ORS), -R )/TPI
GMPH = DH/SQRT( 16.0D0*( DNU + DH2 ) )
GMPK = DK/SQRT( 16.0D0*( DNU + DK2 ) )
BTNCKH = 2*ATAN2( SQRT( XNKH ), SQRT( ONE - XNKH ) )/PI
BTPDKH = 2*SQRT( XNKH*( ONE - XNKH ) )/PI
BTNCHK = 2*ATAN2( SQRT( XNHK ), SQRT( ONE - XNHK ) )/PI
BTPDHK = 2*SQRT( XNHK*( ONE - XNHK ) )/PI
DO J = 1, NU/2
BVT = BVT + GMPH*( ONE + KS*BTNCKH )
BVT = BVT + GMPK*( ONE + HS*BTNCHK )
BTNCKH = BTNCKH + BTPDKH
BTPDKH = 2*J*BTPDKH*( ONE - XNKH )/( 2*J + 1 )
BTNCHK = BTNCHK + BTPDHK
BTPDHK = 2*J*BTPDHK*( ONE - XNHK )/( 2*J + 1 )
GMPH = GMPH*( 2*J - 1 )/( 2*J*( ONE + DH2/DNU ) )
GMPK = GMPK*( 2*J - 1 )/( 2*J*( ONE + DK2/DNU ) )
END DO
ELSE ! NU is ODD
DHDK = DH*DK
QHRK = SQRT( DH2 + DK2 - 2.0D0*R*DHDK + DNU*ORS )
HKRN = DHDK + R*DNU
HKN = DHDK - DNU
HPK = DH + DK
BVT = ATAN2( -SNU*( HKN*QHRK + HPK*HKRN ),
& HKN*HKRN-DNU*HPK*QHRK )/TPI
IF ( BVT < -EPS ) BVT = BVT + ONE
GMPH = DH/( TPI*SNU*( ONE + DH2/DNU ) )
GMPK = DK/( TPI*SNU*( ONE + DK2/DNU ) )
BTNCKH = SQRT( XNKH )
BTPDKH = BTNCKH
BTNCHK = SQRT( XNHK )
BTPDHK = BTNCHK
DO J = 1, ( NU - 1 )/2
BVT = BVT + GMPH*( ONE + KS*BTNCKH )
BVT = BVT + GMPK*( ONE + HS*BTNCHK )
BTPDKH = ( 2*J - 1 )*BTPDKH*( ONE - XNKH )/( 2*J )
BTNCKH = BTNCKH + BTPDKH
BTPDHK = ( 2*J - 1 )*BTPDHK*( ONE - XNHK )/( 2*J )
BTNCHK = BTNCHK + BTPDHK
GMPH = 2*J*GMPH/( ( 2*J + 1 )*( ONE + DH2/DNU ) )
GMPK = 2*J*GMPK/( ( 2*J + 1 )*( ONE + DK2/DNU ) )
END DO
END IF
BVTL = BVT
END IF
END FUNCTION BVTL
DOUBLE PRECISION FUNCTION TVTL( NU1, H, R, EPSI )
USE TRIVARIATEVAR !Block to transfer variables to TVTMFN
IMPLICIT NONE
!
! A function for computing trivariate normal and t-probabilities.
! This function uses algorithms developed from the ideas
! described in the papers:
! R.L. Plackett, Biometrika 41(1954), pp. 351-360.
! Z. Drezner, Math. Comp. 62(1994), pp. 289-294.
! with adaptive integration from (0,0,1) to (0,0,r23) to R.
!
! Calculate the probability that X(I) < H(I), for I = 1,2,3
! NU INTEGER degrees of freedom; use NU = 0 for normal cases.
! H REAL array of uppoer limits for probability distribution
! R REAL array of three correlation coefficients, R should
! contain the lower left portion of the correlation matrix r.
! R should contains the values r21, r31, r23 in that order.
! EPSI REAL required absolute accuracy; maximum accuracy for most
! computations is approximately 1D-14
!
! The software is based on work described in the paper
! "Numerical Computation of Rectangular Bivariate and Trivariate
! Normal and t Probabilities", by the code author:
!
! Alan Genz
! Department of Mathematics
! Washington State University
! Pullman, WA 99164-3113
! Email : alangenz@wsu.edu
!
! EXTERNAL TVTMFN
INTEGER, INTENT(IN) :: NU1
DOUBLE PRECISION,DIMENSION(:), INTENT(IN) :: H, R
DOUBLE PRECISION, INTENT(IN) :: EPSI
!Locals
DOUBLE PRECISION :: R12, R13, TVT
DOUBLE PRECISION :: ONE, ZERO, EPS, PT
! DOUBLE PRECISION RUA, RUB, AR, RUC,
! BVTL, PHID, ADONET
PARAMETER ( ZERO = 0.0D0, ONE = 1.0D0 )
PARAMETER ( PT = 1.57079632679489661923132169163975D0 ) !pi/2
! COMMON /TVTMBK/ H1, H2, H3, R23, RUA, RUB, AR, RUC, NU
EPS = MAX( 1.0D-13, EPSI )
! PT = ASIN(ONE)
NU = NU1
H1 = H(1)
H2 = H(2)
H3 = H(3)
R12 = R(1)
R13 = R(2)
R23 = R(3)
!
! Sort R's and check for special cases
!
IF ( ABS(R12) .GT. ABS(R13) ) THEN
H2 = H3
H3 = H(2)
R12 = R13
R13 = R(1)
END IF
IF ( ABS(R13) .GT. ABS(R23) ) THEN
H1 = H2
H2 = H(1)
R23 = R13
R13 = R(3)
END IF
TVT = 0
IF ( ABS(H1) + ABS(H2) + ABS(H3) < EPS ) THEN
TVT = (ONE + (ASIN(R12) + ASIN(R13) + ASIN(R23))/PT )*0.125D0
ELSE IF ( NU < 1 .AND. ABS(R12) + ABS(R13) < EPS ) THEN
TVT = FI(H1)*BVTL( NU, H2, H3, R23 )
ELSE IF ( NU < 1 .AND. ABS(R13) + ABS(R23) < EPS ) THEN
TVT = FI(H3)*BVTL( NU, H1, H2, R12 )
ELSE IF ( NU < 1 .AND. ABS(R12) + ABS(R23) < EPS ) THEN
TVT = FI(H2)*BVTL( NU, H1, H3, R13 )
ELSE IF ( ONE - R23 < EPS ) THEN
TVT = BVTL( NU, H1, MIN( H2, H3 ), R12 )
ELSE IF ( R23 + ONE < EPS ) THEN
IF ( H2 .GT. -H3 )
& TVT = BVTL( NU, H1, H2, R12 ) - BVTL( NU, H1, -H3, R12 )
ELSE
!
! Compute singular TVT value
!
IF ( NU < 1 ) THEN
TVT = BVTL( NU, H2, H3, R23 )*FI(H1)
ELSE IF ( R23 .GE. ZERO ) THEN
TVT = BVTL( NU, H1, MIN( H2, H3 ), ZERO )
ELSE IF ( H2 .GT. -H3 ) THEN
TVT = BVTL( NU, H1, H2, ZERO ) - BVTL( NU, H1, -H3, ZERO )
END IF
!
! Use numerical integration to compute probability
!
!
RUA = ASIN( R12 )
RUB = ASIN( R13 )
AR = ASIN( R23)
RUC = SIGN( PT, AR ) - AR
TVT = TVT + ADONET(TVTMFN, ZERO, ONE, EPS )/( 4.D0*PT )
END IF
TVTL = MAX( ZERO, MIN( TVT, ONE ) )
END FUNCTION TVTL
! CONTAINS
!
DOUBLE PRECISION FUNCTION TVTMFN( X )
USE TRIVARIATEVAR
IMPLICIT NONE
!
! Computes Plackett formula integrands
!
DOUBLE PRECISION, INTENT(IN) :: X
! Locals
DOUBLE PRECISION R12, RR2, R13, RR3, R, RR, ZRO !, PNTGND
! Parameters transfeered from TRIVARIATEVAR
! INTEGER :: NU
! DOUBLE PRECISION :: H1, H2, H3, R23, RUA, RUB, AR, RUC
PARAMETER ( ZRO = 0.0D0 )
! COMMON /TVTMBK/ H1, H2, H3, R23, RUA, RUB, AR, RUC, NU
TVTMFN = 0.0D0
CALL SINCS( RUA*X, R12, RR2 )
CALL SINCS( RUB*X, R13, RR3 )
IF ( ABS(RUA) .GT. ZRO )
& TVTMFN = TVTMFN + RUA*PNTGND( NU, H1,H2,H3, R13,R23,R12,RR2 )
IF ( ABS(RUB) .GT. ZRO )
& TVTMFN = TVTMFN + RUB*PNTGND( NU, H1,H3,H2, R12,R23,R13,RR3 )
IF ( NU .GT. 0 ) THEN
CALL SINCS( AR + RUC*X, R, RR )
TVTMFN = TVTMFN - RUC*PNTGND( NU, H2, H3, H1, ZRO, ZRO, R, RR )
END IF
move directory structure up, change root to: pywafo/src/* > wafo/*
9 years ago
END FUNCTION TVTMFN
Initial import of original WAFO code.
15 years ago
!
SUBROUTINE SINCS( X, SX, CS )
!
! Computes SIN(X), COS(X)^2, with series approx. for |X| near PI/2
!
DOUBLE PRECISION, INTENT(IN) :: X
DOUBLE PRECISION, INTENT(OUT) :: SX, CS
!Locals
DOUBLE PRECISION :: EE, PT, KS, KC, ONE, SMALL, HALF, ONETHIRD
PARAMETER (ONE = 1.0D0, SMALL = 5.0D-5, HALF = 0.5D0 )
PARAMETER ( PT = 1.57079632679489661923132169163975D0 )
PARAMETER ( KS = 0.0833333333333333333333333333333D0) !1/12
PARAMETER ( KC = 0.1333333333333333333333333333333D0) !2/15
PARAMETER ( ONETHIRD = 0.33333333333333333333333333333333D0) !1/3
EE = ( PT - ABS(X) )
EE = EE * EE
IF ( EE < SMALL ) THEN
SX = SIGN( ONE - EE*( ONE - EE*KS )*HALF, X )
CS = EE *( ONE - EE*( ONE - EE*KC )*ONETHIRD)
ELSE
SX = SIN(X)
CS = ONE - SX*SX
END IF
END SUBROUTINE SINCS
!
DOUBLE PRECISION FUNCTION PNTGND( NU, BA, BB, BC, RA, RB, R, RR )
IMPLICIT NONE
!
! Computes Plackett formula integrand
!
INTEGER, INTENT(IN) :: NU
DOUBLE PRECISION, INTENT(IN) :: BA, BB, BC, RA, RB, R, RR
! Locals
DOUBLE PRECISION :: DT, FT, BT,RAB2, BARB, rNU!, PHID, STUDNT
PNTGND = 0.0D0
FT = ( RA - RB )
RAB2 = FT*FT
DT = RR*( RR - RAB2 - 2.0D0*RA*RB*( 1.D0 - R ) )
IF ( DT .GT. 0.0D0 ) THEN
BT = ( BC*RR + BA*( R*RB - RA ) + BB*( R*RA -RB ) )/SQRT(DT)
BARB = ( BA - R*BB )
FT = ( BARB * BARB ) / RR + BB * BB
IF ( NU < 1 ) THEN
IF ( BT .GT. -10.0D0 .AND. FT < 100.0D0 ) THEN
PNTGND = EXP( -FT * 0.5D0 ) * FI( BT )
! PNTGND = EXP( -FT*0.5D0)
! IF ( BT < 10.0D0 ) PNTGND = PNTGND * FI(BT)
END IF
ELSE
rNU = NU
FT = SQRT( 1.0D0 + FT/rNU )
PNTGND = STUDNT( NU, BT/FT )/FT**NU
END IF
END IF
END FUNCTION PNTGND
!
DOUBLE PRECISION FUNCTION ADONET( F, A, B, TOL )
IMPLICIT NONE
!
! One Dimensional Globally Adaptive Integration Function
!
! EXTERNAL F
DOUBLE PRECISION, INTENT(IN) :: A, B, TOL
INTEGER :: NL, I, IM, IP
PARAMETER ( NL = 100 )
DOUBLE PRECISION, DIMENSION(NL) :: EI, AI, BI, FI
DOUBLE PRECISION :: FIN, ERR !, KRNRDT
DOUBLE PRECISION, PARAMETER :: ZERO = 0.0D0
DOUBLE PRECISION, PARAMETER :: HALF = 0.5D0
DOUBLE PRECISION, PARAMETER :: ONE = 1.0D0
DOUBLE PRECISION, PARAMETER :: FOUR = 4.0D0
INTERFACE
FUNCTION F(Z) RESULT (VAL)
DOUBLE PRECISION, INTENT(IN) :: Z
DOUBLE PRECISION :: VAL
END FUNCTION F
END INTERFACE
! COMMON /ABLK/ ERR, IM
AI(1) = A
BI(1) = B
ERR = ONE
IP = 1
IM = 1
DO WHILE ( (ERR .GT. TOL) .AND. (IM < NL) )
IM = IM + 1
BI(IM) = BI(IP)
AI(IM) = ( AI(IP) + BI(IP) ) * HALF
BI(IP) = AI(IM)
FI(IP) = KRNRDT( AI(IP), BI(IP), F, EI(IP) )
FI(IM) = KRNRDT( AI(IM), BI(IM), F, EI(IM) )
ERR = ZERO
FIN = ZERO
DO I = 1, IM
IF ( EI(I) .GT. EI(IP) ) IP = I
FIN = FIN + FI(I)
ERR = ERR + EI(I)*EI(I)
END DO
ERR = FOUR * SQRT( ERR )
END DO
ADONET = FIN
END FUNCTION ADONET
!
DOUBLE PRECISION FUNCTION KRNRDT( A, B, F, ERR )
!
! Kronrod Rule
!
move directory structure up, change root to: pywafo/src/* > wafo/*
9 years ago
DOUBLE PRECISION, intent(in) :: A, B
DOUBLE PRECISION, intent(out) :: ERR
Initial import of original WAFO code.
15 years ago
DOUBLE PRECISION T, CEN, FC, WID, RESG, RESK
!
! The abscissae and weights are given for the interval (-1,1);
! only positive abscissae and corresponding weights are given.
!
! XGK - abscissae of the 2N+1-point Kronrod rule:
! XGK(2), XGK(4), ... N-point Gauss rule abscissae;
! XGK(1), XGK(3), ... optimally added abscissae.
! WGK - weights of the 2N+1-point Kronrod rule.
! WG - weights of the N-point Gauss rule.
!
INTEGER :: J, N
PARAMETER ( N = 11 )
DOUBLE PRECISION, PARAMETER :: HALF = 0.5D0
DOUBLE PRECISION WG(0:(N+1)/2), WGK(0:N), XGK(0:N)
SAVE WG, WGK, XGK
INTERFACE
FUNCTION F(Z) RESULT (VAL)
DOUBLE PRECISION, INTENT(IN) :: Z
DOUBLE PRECISION :: VAL
END FUNCTION F
END INTERFACE
DATA WG( 0)/ 0.2729250867779007D+00/
DATA WG( 1)/ 0.5566856711617449D-01/
DATA WG( 2)/ 0.1255803694649048D+00/
DATA WG( 3)/ 0.1862902109277352D+00/
DATA WG( 4)/ 0.2331937645919914D+00/
DATA WG( 5)/ 0.2628045445102478D+00/
!
DATA XGK( 0)/ 0.0000000000000000D+00/
DATA XGK( 1)/ 0.9963696138895427D+00/
DATA XGK( 2)/ 0.9782286581460570D+00/
DATA XGK( 3)/ 0.9416771085780681D+00/
DATA XGK( 4)/ 0.8870625997680953D+00/
DATA XGK( 5)/ 0.8160574566562211D+00/
DATA XGK( 6)/ 0.7301520055740492D+00/
DATA XGK( 7)/ 0.6305995201619651D+00/
DATA XGK( 8)/ 0.5190961292068118D+00/
DATA XGK( 9)/ 0.3979441409523776D+00/
DATA XGK(10)/ 0.2695431559523450D+00/
DATA XGK(11)/ 0.1361130007993617D+00/
!
DATA WGK( 0)/ 0.1365777947111183D+00/
DATA WGK( 1)/ 0.9765441045961290D-02/
DATA WGK( 2)/ 0.2715655468210443D-01/
DATA WGK( 3)/ 0.4582937856442671D-01/
DATA WGK( 4)/ 0.6309742475037484D-01/
DATA WGK( 5)/ 0.7866457193222764D-01/
DATA WGK( 6)/ 0.9295309859690074D-01/
DATA WGK( 7)/ 0.1058720744813894D+00/
DATA WGK( 8)/ 0.1167395024610472D+00/
DATA WGK( 9)/ 0.1251587991003195D+00/
DATA WGK(10)/ 0.1312806842298057D+00/
DATA WGK(11)/ 0.1351935727998845D+00/
!
! Major variables
!
! CEN - mid point of the interval
! WID - half-length of the interval
! RESG - result of the N-point Gauss formula
! RESK - result of the 2N+1-point Kronrod formula
!
! Compute the 2N+1-point Kronrod approximation to
! the integral, and estimate the absolute error.
!
WID = ( B - A ) * HALF
CEN = ( B + A ) * HALF
FC = F(CEN)
RESG = FC * WG(0)
RESK = FC * WGK(0)
DO J = 1, N
T = WID * XGK(J)
FC = F( CEN - T ) + F( CEN + T )
RESK = RESK + WGK(J) * FC
IF( MOD( J, 2 ) .EQ. 0 ) RESG = RESG + WG(J/2) * FC
END DO
KRNRDT = WID * RESK
ERR = ABS( WID * ( RESK - RESG ) )
END FUNCTION KRNRDT
move directory structure up, change root to: pywafo/src/* > wafo/*
9 years ago
! END FUNCTION TVTL
Initial import of original WAFO code.
15 years ago
FUNCTION GAUSINT (X1, X2, A, B, C, D) RESULT (value)
! USE GLOBALDATA,ONLY: xCutOff
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: X1,X2,A,B,C,D
DOUBLE PRECISION :: value
!Local variables
DOUBLE PRECISION :: Y1,Y2,Y3
DOUBLE PRECISION, PARAMETER :: SQTWOPI1=3.9894228040143d-1 !=1/sqrt(2*pi)
DOUBLE PRECISION, PARAMETER :: XMAX = 37.d0
! Let X be standardized Gaussian variable,
! i.e., X=N(0,1). The function calculate the
! following integral E[I(X1<X<X2)(A+BX)(C+DX)
! where I(X1<X<X2) is an indicator function of
! the set {X1<X<X2}.
IF (X1.GE.X2) THEN
value = 0.d0
RETURN
ENDIF
IF (ABS (X1) .GT.XMAX) THEN
Y1 = 0.d0
ELSE
Y1 = (A * D+B * C + X1 * B * D) * EXP ( - 0.5d0 * X1 * X1)
ENDIF
IF (ABS (X2) .GT.XMAX) THEN
Y2 = 0.d0
ELSE
Y2 = (A * D+B * C + X2 * B * D) * EXP ( - 0.5d0 * X2 * X2)
ENDIF
Y3 = (A * C + B * D) * (FI (X2) - FI (X1) )
value = Y3 + SQTWOPI1 * (Y1 - Y2)
RETURN
END FUNCTION GAUSINT
FUNCTION GAUSINT2 (X1, X2, A, B) RESULT (value)
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: X1,X2,A,B
DOUBLE PRECISION :: value
! Local variables
DOUBLE PRECISION :: X0,Y0,Y1,Y2
DOUBLE PRECISION, PARAMETER :: SQTWOPI1=3.9894228040143d-1 !=1/sqrt(2*pi)
! Let X be standardized Gaussian variable,
! i.e., X=N(0,1). The function calculate the
! following integral E[I(X1<X<X2)ABS(A+BX)]
! where I(X1<X<X2) is an indicator function of
! the set {X1<X<X2}.
IF (X1.GE.X2) THEN
value = 0.d0
RETURN
ENDIF
IF (ABS(B).EQ.0.d0) THEN
value = ABS(A)*(FI(X2)-FI(X1))
RETURN
ENDIF
Y1 = -A*FI(X1)+SQTWOPI1*B*EXP(-0.5d0*X1*X1)
Y2 = A*FI(X2)-SQTWOPI1*B*EXP(-0.5d0*X2*X2)
IF ((B*X1 < -A).AND.(-A < B*X2))THEN
X0 = -A/B
Y0 = 2.d0*(A*FI(X0)-SQTWOPI1*B*EXP(-0.5d0*X0*X0))
value=ABS(Y2-Y1-Y0)
ELSE
value=ABS(Y1+Y2)
ENDIF
RETURN
END FUNCTION GAUSINT2
SUBROUTINE EXLMS(A, X1, X2, INFIN, LOWER, UPPER, Ca,Pa)
IMPLICIT NONE
DOUBLE PRECISION, INTENT(in) :: A, X1, X2
DOUBLE PRECISION, INTENT(out) :: LOWER, UPPER,Ca,Pa
INTEGER,INTENT(in) :: INFIN
! Local variables
DOUBLE PRECISION :: P1
! DOUBLE PRECISION, PARAMETER :: AMAX = 5D15
! Let X be standardized Gaussian variable,
! i.e., X=N(0,1). The function calculate the
! following integral E[I(X1<X<X2)ABS(A+X)]/C(A)
! where I(X1<X<X2) is an indicator function of
! the set {X1<X<X2} and C(A) is a normalization factor
! i.e. E(I(-inf<X<inf)*ABS(A+X)) = C(A)
!
! Pa = probability at the inflection point of the CDF
! Ca = C(A) normalization parameter
! A = location parameter of the inflection point
! X1,X2 = integration limits < infinity
LOWER = 0.d0
UPPER = 1.d0
P1 = EXFUN(-A,A)
Ca = A+2D0*P1
Pa = P1/Ca
IF ( INFIN < 0 ) RETURN
IF ( INFIN .NE. 0 ) THEN
IF (X1.LE.-A) THEN
LOWER = EXFUN(X1,A)/Ca
ELSE
LOWER = 1D0-EXFUN(-X1,-A)/Ca
ENDIF
ENDIF
IF ( INFIN .NE. 1 ) THEN
IF (X2.LE.-A) THEN
UPPER = EXFUN(X2,A)/Ca
ELSE
UPPER = 1D0-EXFUN(-X2,-A)/Ca
ENDIF
ENDIF
RETURN
CONTAINS
FUNCTION EXFUN(X,A) RESULT (P)
DOUBLE PRECISION, INTENT(in) :: X,A
DOUBLE PRECISION :: P
DOUBLE PRECISION, PARAMETER :: SQTWOPI1=3.9894228040143d-1 !=1/sqrt(2*pi)
P = EXP(-X*X*0.5D0)*SQTWOPI1-A*FI(X)
END FUNCTION EXFUN
END SUBROUTINE EXLMS
FUNCTION EXINV(P,A,Ca,Pa) RESULT (VAL)
!EXINV calculates the inverse of the CDF of abs(x+A)*exp(-x^2/2)/SQRT(2*pi)/C(A)
! where C(A) is a normalization parameter depending on A
!
! CALL: val = exinv(P,A,Ca,Pa)
!
! val = quantiles
! p = probabilites
! A = location parameter
! Ca = normalization parameter
! Pa = excdf(-A,A) probability at the inflection point of the CDF
double precision, intent(in) :: P,A,Ca,Pa
double precision :: val
! local variables
double precision, parameter :: amax = 5.D15
double precision, parameter :: epsl = 5.D-15
double precision, parameter :: xmax = 8
double precision :: P1,Xk,Ak,Zk,SGN
! if (P<0.D0.OR.P.GT.1.D0) PRINT *,'warning P<0 or P>1'
! The inverse cdf of 0 is -inf, and the inverse cdf of 1 is inf.
if (P.LE.EPSL.OR.P+EPSL.GE.1.D0) THEN
VAL = SIGN(xmax,P-0.5D0)
return
endif
Ak = ABS(A)
if (EPSL < Ak .AND. Ak < amax) THEN
IF (ABS(p-Pa).LE.EPSL) THEN
VAL = SIGN(MIN(Ak,xmax),-A)
RETURN
ENDIF
IF (Ak < 1D-2) THEN ! starting guess always less than 0.2 from the true value
IF (P.GE.0.5D0) THEN
xk = SQRT(-2D0*log(2D0*(1D0-P)))
ELSE
xk = -SQRT(-2D0*log(2D0*P))
ENDIF
ELSE
xk = FIINV(P) ! starting guess always less than 0.8 from the true value
! Modify starting guess if possible in order to speed up Newtons method
IF (1D-3.LE.P.AND. P.LE.0.99D0.AND.
& 3.5.LE.Ak.AND.Ak.LE.1D3 ) THEN
SGN = SIGN(1.d0,-A)
Zk = xk*SGN
xk = SGN*(Zk+((1D0/(64.9495D0*Ak-178.3191D0)-0.02D0/Ak)*
& Zk+1D0/(-0.99679234298211D0*Ak-0.07195350071872D0))/
& (Zk/(-1.48430620263825D0*Ak-0.33340759016175D0)+1D0))
ELSEIF ((P < 1D-3.AND.A.LE.-3.5D0).OR.
& (3.5D0.LE.A.AND.P.GT.0.99D0)) THEN
SGN = SIGN(1.d0,-A)
Zk = xk*SGN
P1 = -2.00126182192701D0*Ak-2.57306603933111D0
xk = SGN*Zk*(1D0+
& P1/((-0.99179258785909D0*Ak-0.21359746002397D0)*
& (Zk+P1)))
ENDIF
ENDIF
! Check if the starting guess is on the correct side of the inflection point
IF (xk.LE.-A .AND. P.GT.Pa) xk = 1.D-2-A
IF (xk.GE.-A .AND. P < Pa) xk = -1.D-2-A
IF (P < Pa) THEN
VAL = funca(xk,A,P*Ca)
ELSE ! exploit the symmetry of the CDF
VAL = -funca(-xk,-A,(1.D0-P)*Ca)
ENDIF
ELSEIF (ABS(A).LE.EPSL) THEN
IF (P>=0.5D0) THEN
VAL = SQRT(-2D0*log(2D0*(1.D0-P)))
ELSE
VAL = -SQRT(-2D0*log(2D0*P))
ENDIF
ELSE ! ABS(A) > AMAX
VAL = FIINV(P)
ENDIF
!CALL EXLMS(A,0.d0,VAL,0,ak,P1,zk,sgn)
!If (ABS(p-P1).GT.0.0001) PRINT *,'excdf(x,a)-p',p-P1
RETURN
CONTAINS
function funca(xk0,ak,CaP) RESULT (xk)
double precision, intent(in) :: xk0,ak,CaP ! =Ca*P
DOUBLE PRECISION :: xk
!Local variables
INTEGER, PARAMETER :: ixmax = 25
double precision, parameter :: crit = 7.1D-08 ! = sqrt(1e-15)
double precision, parameter :: SQTWOPI1 = 0.39894228040143D0 !=1/SQRT(2*pi)
double precision, parameter :: SQTWOPI = 2.50662827463100D0 !=SQRT(2*pi)
INTEGER :: IX
DOUBLE PRECISION :: H,H1,tmp0,tmp1,XNEW
! Newton's Method or Fixed point iteration to find the inverse of the EXCDF.
! Assumption: xk0 < -ak and xk < -ak
! Permit no more than IXMAX iterations.
IX = 0
H = 1.D0
xk = xk0 ! starting guess for the iteration
! Break out of the iteration loop for the following:
! 1) The last update is very small (compared to x).
! 2) The last update is very small (compared to sqrt(eps)=crit).
! 3) There are more than 15 iterations. This should NEVER happen.
IF (.TRUE..OR.ABS(ak) < 1.D-2) THEN
! Newton's method
!~~~~~~~~~~~~~~~~~
DO WHILE( ABS(H).GT.MIN(crit*ABS(xk),crit).AND.IX < IXMAX)
IX = IX+1
!print *,'Iteration ',IX
tmp0 = FI(xk)
tmp1 = EXP(-xk*xk*0.5D0)*SQTWOPI1 ! =normpdf(x)
H1 = (tmp1-ak*tmp0-CaP)/(ABS(xk+ak)*tmp1)
H = DSIGN(MIN(ABS(H1),0.7D0/DBLE(IX)),H1) ! Only allow smaller and smaller steps
xnew = xk - H
! Make sure that the current guess is less than -a.
! When Newton's Method suggests steps that lead to -a guesses
! take a step 9/10ths of the way to -a:
IF (xnew.GT.-ak-crit) THEN
xnew = (xk - 9.D0*ak)*1D-1
H = xnew - xk
ENDIF
xk = xnew
END DO
ELSE ! FIXED POINT iteration
!~~~~~~~~~~~~~~~~~~~~~~~
DO WHILE (ABS(H).GT.MIN(crit*ABS(xk),crit).AND.IX < IXMAX)
IX = IX+1
tmp0 = SQTWOPI1*EXP(-xk*xk*0.5D0)/FI(xk)
tmp1 = -2.D0*LOG(SQTWOPI*CaP*tmp0/(tmp0-ak))
SGN = sign(1.D0,tmp1)
xnew = -SQRT(SGN*tmp1)*SGN
! Make sure that the current guess is less than -a.
! When this method suggests steps that lead to -a guesses
! take a step 9/10ths of the way to -a:
IF (xnew.GT.-ak-crit) xnew = (xk - 9.D0*ak)*1.D-1
H = xnew - xk
xk = xnew
END DO
ENDIF
!print *,'EXINV total number of iterations ',IX
if (IX.GE.IXMAX) THEN
! print *, 'Warning: EXINV did not converge. Cap=',Cap
! print *, 'The last step was: ', h, ' value=,',xk,' ak=',ak
endif
return
END FUNCTION FUNCA
END FUNCTION EXINV
END MODULE FIMOD