ADAS Subroutine bgtran

C
      SUBROUTINE  BGTRAN( TYP   , C      ,
     &                    AIN   , WVNOU  , WVNOL , WTU   , WTL  ,
     &                    TEIN  , UPSIN  , NV    ,
     &                    x     , y   
     &                  )

C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: BGTRAN *********************
C
C This subroutine is based on ADAS215's bftran.for - it is modified to
C output the Burgess and Tully x and y vectors.
C
C PURPOSE : TO IMPLEMENT THE TRANSFORMATION DESCRIBED BY
C           BURGESS AND TULLY ( SEE REFERENCE (1)) WHICH
C           IS USED TO ASSESS AND COMPACT DATA.
C
C
C REFERENCES:
C           (1) A.BURGESS AND J.A.TULLY
C           ON THE ANALYSIS OF COLLISION STRENGTHS
C           AND RATE COEFFICIENTS.
C           ASTRON.ASTROPHYS.254,436-453 (1992 )
C
C           (2) SUMMERS.H.P
C               ADAS USERS MANUAL ( 1ST EDITION ).
C
C INPUT :
C       (R*8) Z1          = THE ION CHARGE +1.
C       (C*1) TYP         = BURGESS & TULLY TRANSITION TYPE CODE
C       (R*8) C           = THE ADJUSTABLE PARAMETER ASSOCIATED
C                           WITH THE BURGESS AND TULLY
C                           TRANSFORMATION ( SEE REFERENCE (1)).
C       (R*8) AIN         = THE EINSTEIN `A` CO-EFFICIENT. THIS
C                           IS READ DIRECTLY FROM THE ADF04
C                           TYPE FILE.
C       (R*8) WVNOU       = THE WAVENUMBER OF THE UPPER LEVEL.
C                           THIS IS READ DIRECTLY FROM THE ADF04
C                           TYPE FILE.
C       (R*8) WVNLO       = THE WAVENUMBER OF THE LOWER LEVEL.
C                           THIS IS READ DIRECTLY FROM THE ADF04
C                           TYPE FILE.
C       (R*8) WTU         = THE STATISTICAL WEIGHT OF THE UPPER
C                           LEVEL. THIS IS OBTAINED BY
C
C       (R*8) WTL         = THE STATISTICAL WEIGHT OF THE LOWER
C                           LEVEL. THIS IS OBTAINED BY
C
C       (R*8) TEIN        = THE TEMPERATURE ARRAY (K). THIS
C                           DATA IS READ DIRECTLY FROM THE
C                           ADF04 TYPE FILE.
C       (R*8) UPSIN       = THE ARRAY CONTAING THE EFFECTIVE
C                           COLLISION STRENGTH. THIS DATA IS
C                           READ DIRECTLY FROM THE ADF04
C                           TYPE FILE.
C       (I*4) NV          = THE NUMBER OF TEMPERATURE/EFFECTIVE
C                           COLLISION STRENGTH PAIRS FOR A GIVEN
C                           TRANSITION.
C
C OUTPUT:
C
C       (R*8) X           = THE X ARRAY ASSOCIATED WITH THE
C                           BURGESS AND TULLY TRANSFORMATION.
C       (R*8) Y           = THE Y ARRAY ASSOCIATED WITH THE
C                           BURGESS AND TULLY TRANSFORMATION.
C
C
C       (R*8) E           = THE MATHEMATICAL CONSTANT E.
C       (R*8) CONST       = CLUSTER OF PHYSICAL CONSTANTS.
C                           SEE PAGE 12 OF REFERENCE (2).
C       (R*8) EIJIN       = THE TRANSITION ENERGY (RYD).
C       (R*8) FIJIN       = THE OSCILLATOR STRENGTH.
C       (R*8) ET          = GENERAL CONSTANT.
C       (R*8) C           = THE BURGESS C PARAMETER.
C       (R*8) DY          = DERIVATIVES AT INPUT KNOTS.
C                           SEE XXSPLN FOR FUTHER DETAILS.
C       (R*8) XOUT        = X ARRAY ASSOCIATED WITH THE
C                           BURGESS AND TULLY TRANSFORMATION.
C       (R*8) YOUT        = Y ARRAY ASSOCIATED WITH THE
C                           BURGESS AND TULLY TRANSFORMATION.
C       (I*4) NVMAX       = THE MAXIMUM NUMBER OF TEMPERTURES
C                           THAT CAN BE READ.
C       (I*4) IOPT        = GENERAL PARAMETER ASSOCIATED WITH
C                           THE SUBROUTINE XXSPLN.
C       (I*4) I           = GENERAL VARIABLE WHICH IS USED AS
C                           A COUNTER.
C       (LOG) LSETX       = PARAMETER ASSOCIATED WITH THE
C                           SUBROUTINE XXSPLN.
C
C AUTHOR:   H. P. SUMMERS, UNIVERSITY OF STRATHCLYDE
C           JA8.08
C           TEL.  0141-553-4196
C
C DATE:    04/06/98
C
C
C VERSION  : 1.1                          DATE: 17/03/1999
C MODIFIED : MARTIN O'MULLANE
C            FIRST VERSION.
C
C----------------------------------------------------------------
      CHARACTER           TYP
      INTEGER             NV
      REAL*8              AIN,         C,           TEIN(NV)
      REAL*8              UPSIN(NV),   WTL,         WTU,         WVNOL
      REAL*8              WVNOU,       X(NVMAX),    Y(NVMAX)