LHAPDF/lhapdf5.2.2/inputPDF.f

   1
   2       subroutine weightPDF(x)
   3       implicit none
   4       integer nset,imem,nfmax
   5       real*8 x,Q
   6       nset=1
   7       call weightPDFM(nset,x)
   8       return
   9
  10       entry GetNF(nfmax)
  11       nset=1
  12       call GetNFM(nset,nfmax)
  13       return
  14
  15       entry GetThreshold(imem,Q)
  16       nset=1
  17       call GetThresholdM(nset,imem,Q)
  18       return
  19
  20       end
  21
  22       subroutine parmPDF(nset,x,pdf)
  23       implicit none
  24       include 'parmsetup.inc'
  25       integer nset
  26       character*16 name(nmxset)
  27       integer nmem(nmxset),ndef(nmxset),mem
  28       common/NAME/name,nmem,ndef,mem
  29       real*4 xp(40),x4,fgdis4
  30       character*16 s1,s2
  31       integer i,j,imem,nop,parmN,Nfunc(nmxset),Fw(nmxset),nfmax,M
  32       real*8 x,N,b0,Poly,pdf(-6:6),Fparm(nopmax),F(nofmax)
  33       real*8 Ccoef(nmxset,-6:6,nofmax),Fpow(nmxset,nofmax)
  34       real*8 Q,Treshold(nmxset,-6:6)
  35 c      data Treshold/39*0d0/
  36       integer Fmap(nmxset,nofmax,npfmax)
  37       integer Ftype(nmxset,nofmax),Fn(nmxset,nofmax),Ctype(nmxset,-6:6)
  38       integer lhasilent
  39       common/lhasilent/lhasilent
  40       logical first
  41       data first/.true./
  42       save Nfunc,Fn,Fw,Fpow,Fmap,Ccoef,Fparm,Ftype,Ctype,first,Treshold
  43
  44       do i=1,Nfunc(nset)
  45          if (Ftype(nset,i).eq.1) then
  46             Poly=1.0
  47
  48             do j=4,Fn(nset,i)
  49          Poly=Poly+Fparm(Fmap(nset,i,j))*x**(float(j-3)/Fpow(nset,i))
  50             enddo
  51             Poly=Fparm(Fmap(nset,i,1))*Poly
  52        F(i)=x**Fparm(Fmap(nset,i,2))*(1.0-x)**Fparm(Fmap(nset,i,3))*Poly
  53          endif
  54          if (Ftype(nset,i).eq.2) then
  55             if (x.lt.0.9999999) then
  56       Poly=Fparm(Fmap(nset,i,2))*log(x)+Fparm(Fmap(nset,i,3))*log(1.0-x)
  57      .      +Fparm(Fmap(nset,i,4))*x
  58      .      +Fparm(Fmap(nset,i,6))*log(1.0+x*exp(Fparm(Fmap(nset,i,5))))
  59          F(i)=Fparm(Fmap(nset,i,1))*exp(Poly)
  60             else
  61                F(i)=0d0
  62             endif
  63          endif
  64          if (Ftype(nset,i).eq.101) then
  65        Poly=exp(Fparm(Fmap(nset,i,1)))*x**(Fparm(Fmap(nset,i,2))-1)
  66      .       *(1d0-x)**Fparm(Fmap(nset,i,3))
  67        Poly=
  68      . Poly+(1d0+Fparm(Fmap(nset,i,4))*x)*(1d0-x)**Fparm(Fmap(nset,i,5))
  69             b0=10d0
  70             if (Poly.gt.b0) then
  71                F(i)=Poly
  72             elseif (Poly.lt.-b0) then
  73                F(i)=0d0
  74             else
  75                F(i)=Poly+log(1d0+exp(-b0*Poly)-exp(-b0))/b0
  76             endif
  77          endif
  78 c - to add the mrst2004 gluon convolution
  79          if (Ftype(nset,i).eq.201) then
  80            xp(2) = Fparm(Fmap(nset,i,1))
  81            xp(3) = Fparm(Fmap(nset,i,2))
  82            xp(23)= Fparm(Fmap(nset,i,3))
  83            xp(16)= Fparm(Fmap(nset,i,4))
  84            xp(5) = Fparm(Fmap(nset,i,5))
  85            xp(40)= Fparm(Fmap(nset,i,6))
  86            xp(24)= Fparm(Fmap(nset,i,7))
  87            xp(20)= Fparm(Fmap(nset,i,8))
  88            xp(4) = Fparm(Fmap(nset,i,9))
  89            xp(1) = Fparm(Fmap(nset,i,10))
  90            x4 = x
  91            call gconv(x4,xp,fgdis4)
  92           F(i) = FGDIS4
  93          endif
  94 c--
  95       enddo
  96       do i=-6,6
  97          pdf(i)=0.0
  98          if (Ctype(nset,i).gt.0) then
  99             if (Ctype(nset,i).eq.1) then
 100                do j=1,Nfunc(nset)
 101                   pdf(i)=pdf(i)+Ccoef(nset,i,j)*F(j)
 102 c                 print *,i,j,Ccoef(i,j),F(j)
 103                enddo
 104             endif
 105             if (Ctype(nset,i).eq.101) then
 106                if (i.eq.-2) then
 107        pdf(i)=F(int(Ccoef(nset,i,1)))/(F(int(Ccoef(nset,i,2)))+1d0)
 108                endif
 109                if (i.eq.-1) then
 110       pdf(i)=
 111      .F(int(Ccoef(nset,i,1)))/(1d0/F(int(Ccoef(nset,i,2)))+1d0)
 112                endif
 113                if (i.eq.1) then
 114                   pdf(i)=F(1)+pdf(-1)
 115                endif
 116                if (i.eq.2) then
 117                   pdf(i)=F(2)+pdf(-2)
 118                endif
 119             endif
 120          endif
 121       enddo
 122 c      print *,pdf
 123       return
 124 *
 125       entry weightPDFM(nset,x)
 126       if (Fw(nset).ge.0) then
 127          x=Fparm(Fw(nset))
 128       else
 129          call numberPDF(nop)
 130          x=1.0/float(nop)
 131       endif
 132       return
 133 *
 134 c      entry GetParmPDFM(nset,imem,x)
 135       entry GetParmPDF(nset,imem,x)
 136       x=Fparm(imem)
 137       return
 138 *
 139       entry GetNfM(nset,nfmax)
 140       nfmax=0
 141       do i=1,6
 142          if (Treshold(nset,-i).ge.0d0) nfmax=nfmax+1
 143          if (Treshold(nset,i).ge.0d0) nfmax=nfmax+1
 144       enddo
 145       nfmax=nfmax/2
 146       return
 147 *
 148       entry GetThresholdM(nset,imem,Q)
 149       Q=Treshold(nset,imem)
 150       return
 151 *
 152 c      entry InitEvolvePDFM(nset,imem)
 153       entry InitEvolvePDF(nset,imem)
 154 c      print*, 'calling listPDF',nset,imem
 155       call listPDF(nset,imem,Fparm)
 156 c      print *,Fparm
 157       return
 158 *
 159 c      entry initInputPDFM(nset)
 160       entry initInputPDF(nset)
 161
 162       if(first) then
 163         do i=1,nmxset
 164           do j=-6,6
 165              Treshold(i,j)=0.0d0
 166           enddo
 167         enddo
 168         first=.false.
 169       endif
 170       read(1,*) s1,Fw(nset),Nfunc(nset)
 171 c      print *,s1,Fw,Nfunc
 172       if(lhasilent.eq.0) then
 173         write(*,*) 'Parametrization: ',s1
 174         write(*,*)
 175       endif
 176       do i=1,Nfunc(nset)
 177          Ftype(nset,i)=-1
 178          read(1,*) s1,s2
 179          if (index(s2,'x-taylor').eq.1) then
 180             Ftype(nset,i)=1
 181             read(1,*) FPow(nset,i),Fn(nset,i)
 182             read(1,*) (Fmap(nset,i,j),j=1,Fn(nset,i))
 183          endif
 184          if (index(s2,'log-pade').eq.1) then
 185             Ftype(nset,i)=2
 186             FPow(nset,i)=0d0
 187             read(1,*) Fn(nset,i)
 188             read(1,*) (Fmap(nset,i,j),j=1,Fn(nset,i))
 189          endif
 190          if (index(s2,'cteq6-ratio').eq.1) then
 191             Ftype(nset,i)=101
 192             Fpow(nset,i)=0d0
 193             Fn(nset,i)=5
 194             read(1,*) (Fmap(nset,i,j),j=1,Fn(nset,i))
 195          endif
 196          if (index(s2,'convol').eq.1) then
 197             Ftype(nset,i)=201
 198             read(1,*) Fn(nset,i)
 199             read(1,*) (Fmap(nset,i,j),j=1,Fn(nset,i))
 200          endif
 201          if (Ftype(nset,i).lt.0) then
 202             write(*,*) 'File description error:'
 203             write(*,*) 'Unknown functional ',s2
 204             stop
 205          endif
 206       enddo
 207       read(1,*) s1
 208       do i=-6,6
 209          Ctype(nset,i)=-1
 210          read(1,*) s1,s2
 211 c        print *,s1,s2
 212          if (index(s2,'none').eq.1) then
 213             Ctype(nset,i)=0
 214             Treshold(nset,i)=-1d0
 215          endif
 216          if (index(s2,'treshold').eq.1) then
 217             Ctype(nset,i)=0
 218             read(1,*) Treshold(nset,i)
 219          endif
 220          if (index(s2,'composite').eq.1) then
 221             Ctype(nset,i)=1
 222             Treshold(nset,i)=0d0
 223             read(1,*) (Ccoef(nset,i,j),j=1,Nfunc(nset))
 224          endif
 225          if (index(s2,'cteq6-ratio').eq.1) then
 226             Ctype(nset,i)=101
 227             Treshold(nset,i)=0d0
 228             read(1,*) (Ccoef(nset,i,j),j=1,3)
 229          endif
 230          if (Ctype(nset,i).lt.0) then
 231             write(*,*) 'File description error:'
 232             write(*,*) 'Unknown composit type ',s2
 233             stop
 234          endif
 235       enddo
 236       if (Fw(nset).ge.0) then
 237          write(*,*) '***********************************************'
 238          write(*,*) '* Note that this is a weigthed PDF set.       *'
 239          write(*,*) '* See manual for proper use.                  *'
 240          write(*,*) '***********************************************'
 241       endif
 242       return
 243 *
 244       end
 245
 246       FUNCTION BETA_LHA(X1,X2)
 247       CALL GAMMA_LHA(X1,G1,IER)
 248       IF(IER.NE.0) write(16,*) 'GAMMA_LHA ERROR: IER= ',IER,X1,X2
 249       CALL GAMMA_LHA(X2,G2,IER)
 250       IF(IER.NE.0) write(16,*) 'GAMMA_LHA ERROR: IER= ',IER,X1,X2
 251       X3=X1+X2
 252       CALL GAMMA_LHA(X3,G3,IER)
 253       IF(IER.NE.0) write(16,*) 'GAMMA_LHA ERROR: IER= ',IER,X1,X2
 254       BETA_LHA=G1*G2/G3
 255       RETURN
 256       END
 257
 258       SUBROUTINE GAMMA_LHA(XX,GX,IER)
 259       IF(XX-34.5)6,6,4
 260     4 IER=2
 261       GX=1.E38
 262       RETURN
 263     6 X=XX
 264       ERR=1.0E-6
 265       IER=0
 266       GX=1.0
 267       IF(X-2.0)50,50,15
 268    10 IF(X-2.0)110,110,15
 269    15 X=X-1.0
 270       GX=GX*X
 271       GO TO 10
 272    50 IF(X-1.0)60,120,110
 273 C        SEE IF X IS NEAR NEGATIVE INTEGER OR ZERO
 274    60 IF(X-ERR)62,62,80
 275    62 K=X
 276       Y=FLOAT(K)-X
 277       IF(ABS(Y)-ERR)130,130,64
 278    64 IF(1.0-Y-ERR)130,130,70
 279 C        X NOT NEAR A NEGATIVE INTEGER OR ZERO
 280    70 IF(X-1.0)80,80,110
 281    80 GX=GX/X
 282       X=X+1.0
 283       GO TO 70
 284   110 Y=X-1.0
 285       GY=1.0+Y*(-0.5771017+Y*(+0.9858540+Y*(-0.8764218+Y*(+0.8328212+
 286      1Y*(-0.5684729+Y*(+0.2548205+Y*(-0.05149930)))))))
 287       GX=GX*GY
 288   120 RETURN
 289   130 IER=1
 290       RETURN
 291       END
 292
 293       FUNCTION  ALPHA(T,AL)
 294       COMMON/AINPUT/IORD,QSCT,QSDT
 295       COMMON/PARAM/PARA(40)
 296       DATA PI/3.14159/
 297       DATA TOL/.0005/
 298       ITH=0
 299       TT=T
 300       qsctt=qsct/4.
 301       qsdtt=qsdt/4.
 302 c      AL=para(1)
 303       AL2=AL*AL
 304       FLAV=4.
 305       QS=AL2*EXP(T)
 306
 307       if(qs.lt.0.5d0) then   !!  running stops below 0.5
 308           qs=0.5d0
 309           t=alog(qs/al2)
 310           tt=t
 311       endif
 312
 313       IF(QS.gt.QSCTT) GO        TO 12
 314       IF(QS.lt.QSDTT) GO        TO 312
 315    11 CONTINUE
 316       B0=11-2.*FLAV/3.
 317       IF(IORD)1,1,2
 318 c     IF(IORD)2,2,2     !TAKE CARE !!
 319     1 CONTINUE
 320       ALPHA=4.*PI/B0/T
 321       RETURN
 322     2 CONTINUE
 323       X1=4.*PI/B0
 324       B1=102.-38.*FLAV/3.
 325       X2=B1/B0**2
 326       AS=X1/T*(1.-X2*aLOG(T)/T)
 327     5 CONTINUE
 328       F=-T+X1/AS-X2*aLOG(X1/AS+X2)
 329       FP=-X1/AS**2*(1.-X2/(X1/AS+X2))
 330       AS2=AS-F/FP
 331       DEL=ABS(F/FP/AS)
 332       IF(DEL-TOL)3,3,4
 333     3 CONTINUE
 334       ALPHA=AS2
 335       IF(ITH.EQ.0) RETURN
 336       GO TO (13,14,15) ITH
 337     4 CONTINUE
 338       AS=AS2
 339       GO TO 5
 340    12 ITH=1
 341       T=aLOG(QSCTT/AL2)
 342       GO TO 11
 343    13 ALFQC4=ALPHA
 344       FLAV=5.
 345       ITH=2
 346       GO TO 11
 347    14 ALFQC5=ALPHA
 348       ITH=3
 349       T=TT
 350       GO TO 11
 351    15 ALFQS5=ALPHA
 352       ALFINV=1./ALFQS5+1./ALFQC4-1./ALFQC5
 353       ALPHA=1./ALFINV
 354       RETURN
 355
 356   311 CONTINUE
 357       B0=11-2.*FLAV/3.
 358       IF(IORD)31,31,32
 359 c     IF(IORD)32,32,32  !TAKE CARE !!
 360    31 CONTINUE
 361       ALPHA=4.*PI/B0/T
 362       RETURN
 363    32 CONTINUE
 364       X1=4.*PI/B0
 365       B1=102.-38.*FLAV/3.
 366       X2=B1/B0**2
 367       AS=X1/T*(1.-X2*aLOG(T)/T)
 368    35 CONTINUE
 369       F=-T+X1/AS-X2*aLOG(X1/AS+X2)
 370       FP=-X1/AS**2*(1.-X2/(X1/AS+X2))
 371       AS2=AS-F/FP
 372       DEL=ABS(F/FP/AS)
 373       IF(DEL-TOL)33,33,34
 374    33 CONTINUE
 375       ALPHA=AS2
 376       IF(ITH.EQ.0) RETURN
 377       GO TO (313,314,315) ITH
 378    34 CONTINUE
 379       AS=AS2
 380       GO TO 35
 381   312 ITH=1
 382       T=aLOG(QSDTT/AL2)
 383       GO TO 311
 384   313 ALFQC4=ALPHA
 385       FLAV=3.
 386       ITH=2
 387       GO TO 311
 388   314 ALFQC3=ALPHA
 389       ITH=3
 390       T=TT
 391       GO TO 311
 392   315 ALFQS3=ALPHA
 393       ALFINV=1./ALFQS3+1./ALFQC4-1./ALFQC3
 394       ALPHA=1./ALFINV
 395       RETURN
 396       END
 397
 398       SUBROUTINE WATE96
 399 C*******************************************************************
 400 C*****                                                         *****
 401 C***** THE X(I) AND W(I) ARE THE DIRECT OUTPUT FROM A PROGRAM  *****
 402 C***** USING NAG ROUTINE D01BCF TO CALCULATE THE               *****
 403 C***** GAUSS-LEGENDRE WEIGHTS FOR 96 POINT INTEGRATION.        *****
 404 C***** THEY AGREE TO TYPICALLY 14 DECIMAL PLACES WITH THE      *****
 405 C***** TABLE IN ABRAMOWITZ & STEGUN, PAGE 919.                 *****
 406 C*****                                                         *****
 407 C***** ---->   PETER HARRIMAN, APRIL 3RD 1990.                 *****
 408 C*****                                                         *****
 409 C*******************************************************************
 410       DIMENSION X(48),W(48)
 411       COMMON/GAUS96/XI(96),WI(96),nterms,XX(97)
 412       NTERMS=96
 413
 414       X( 1)=   0.01627674484960183561
 415       X( 2)=   0.04881298513604856015
 416       X( 3)=   0.08129749546442434360
 417       X( 4)=   0.11369585011066471632
 418       X( 5)=   0.14597371465489567682
 419       X( 6)=   0.17809688236761733390
 420       X( 7)=   0.21003131046056591064
 421       X( 8)=   0.24174315616383866556
 422       X( 9)=   0.27319881259104774468
 423       X(10)=   0.30436494435449495954
 424       X(11)=   0.33520852289262397655
 425       X(12)=   0.36569686147231213885
 426       X(13)=   0.39579764982890709712
 427       X(14)=   0.42547898840729897474
 428       X(15)=   0.45470942216774136446
 429       X(16)=   0.48345797392059470382
 430       X(17)=   0.51169417715466604391
 431       X(18)=   0.53938810832435567233
 432       X(19)=   0.56651041856139533470
 433       X(20)=   0.59303236477757022282
 434       X(21)=   0.61892584012546672523
 435       X(22)=   0.64416340378496526886
 436       X(23)=   0.66871831004391424358
 437       X(24)=   0.69256453664216964528
 438       X(25)=   0.71567681234896561582
 439       X(26)=   0.73803064374439816819
 440       X(27)=   0.75960234117664555964
 441       X(28)=   0.78036904386743123629
 442       X(29)=   0.80030874413913884180
 443       X(30)=   0.81940031073792957139
 444       X(31)=   0.83762351122818502758
 445       X(32)=   0.85495903343459936363
 446       X(33)=   0.87138850590929436968
 447       X(34)=   0.88689451740241818933
 448       X(35)=   0.90146063531585023110
 449       X(36)=   0.91507142312089592706
 450       X(37)=   0.92771245672230655266
 451       X(38)=   0.93937033975275308073
 452       X(39)=   0.95003271778443564022
 453       X(40)=   0.95968829144874048809
 454       X(41)=   0.96832682846326217918
 455       X(42)=   0.97593917458513455843
 456       X(43)=   0.98251726356301274934
 457       X(44)=   0.98805412632962202890
 458       X(45)=   0.99254390032376081654
 459       X(46)=   0.99598184298720747465
 460       X(47)=   0.99836437586317963722
 461       X(48)=   0.99968950388322870559
 462       W( 1)=   0.03255061449236316962
 463       W( 2)=   0.03251611871386883307
 464       W( 3)=   0.03244716371406427668
 465       W( 4)=   0.03234382256857594104
 466       W( 5)=   0.03220620479403026124
 467       W( 6)=   0.03203445623199267876
 468       W( 7)=   0.03182875889441101874
 469       W( 8)=   0.03158933077072719007
 470       W( 9)=   0.03131642559686137819
 471       W(10)=   0.03101033258631386231
 472       W(11)=   0.03067137612366917839
 473       W(12)=   0.03029991542082762553
 474       W(13)=   0.02989634413632842385
 475       W(14)=   0.02946108995816795100
 476       W(15)=   0.02899461415055528410
 477       W(16)=   0.02849741106508543861
 478       W(17)=   0.02797000761684838950
 479       W(18)=   0.02741296272602931385
 480       W(19)=   0.02682686672559184485
 481       W(20)=   0.02621234073567250055
 482       W(21)=   0.02557003600534944960
 483       W(22)=   0.02490063322248370695
 484       W(23)=   0.02420484179236479915
 485       W(24)=   0.02348339908592633665
 486       W(25)=   0.02273706965832950717
 487       W(26)=   0.02196664443874448477
 488       W(27)=   0.02117293989219144572
 489       W(28)=   0.02035679715433347898
 490       W(29)=   0.01951908114014518992
 491       W(30)=   0.01866067962741165898
 492       W(31)=   0.01778250231604547316
 493       W(32)=   0.01688547986424539715
 494       W(33)=   0.01597056290256253144
 495       W(34)=   0.01503872102699521608
 496       W(35)=   0.01409094177231515264
 497       W(36)=   0.01312822956696188190
 498       W(37)=   0.01215160467108866759
 499       W(38)=   0.01116210209983888144
 500       W(39)=   0.01016077053500880978
 501       W(40)=   0.00914867123078384552
 502       W(41)=   0.00812687692569928101
 503       W(42)=   0.00709647079115442616
 504       W(43)=   0.00605854550423662775
 505       W(44)=   0.00501420274292825661
 506       W(45)=   0.00396455433844564804
 507       W(46)=   0.00291073181793626202
 508       W(47)=   0.00185396078894924657
 509       W(48)=   0.00079679206555731759
 510       DO 1 I=1,48
 511       XI(I)=-X(49-I)
 512       WI(I)=W(49-I)
 513       XI(I+48)=X(I)
 514       WI(I+48)=W(I)
 515     1 CONTINUE
 516       DO 2 I=1,96
 517     2 XX(I)=0.5*(XI(I)+1.)
 518       XX(97)=1.0
 519       EXPON=1.0
 520       DO 3 I=1,96
 521       YI=2.*(0.5*(1.+XI(I)))**EXPON-1.
 522       WI(I)=WI(I)/(1.+XI(I))*(1.+YI)*EXPON
 523       XI(I)=YI
 524       XX(I)=0.5*(1.+YI)
 525     3 CONTINUE
 526       RETURN
 527       END
 528
 529       subroutine gconv(x,xp,fgdis)
 530       COMMON/AINPUT/IORD,QSCT,QSDT
 531       common/GAUS96/XI(96),WI(96),NTERMS,XX(97)
 532       dimension xp(40)
 533       logical first
 534       data first/.true./
 535       if(first) then
 536          call wate96
 537          first=.false.
 538       endif
 539       PI = 3.14159
 540       PI2 = PI*PI
 541       iord = 1
 542       qsdt=8.18    !!  This is the value of 4m_c^2
 543       qsct=74.0    !!  This is the value of 4m_b^2
 544       cf = 4./3.
 545       eta4 = xp(40)
 546       T=alog(1/xp(1)**2)
 547 c      AL = 0.550/(4.* 3.14159)
 548       AL=ALPHA(T,xp(1))/(4.* pi)
 549       rx=sqrt(x)
 550       FF1=BETA_LHA(XP(2),XP(3)+1.)+XP(16)*BETA_LHA(XP(2)+1.,XP(3)+1.)+
 551      XXP(23)*BETA_LHA(XP(2)+0.5,XP(3)+1.)
 552       FF2=BETA_LHA(XP(2)+1.,XP(3)+1.)+
 553      XXP(16)*BETA_LHA(XP(2)+2.,XP(3)+1.)+
 554      XXP(23)*BETA_LHA(XP(2)+1.5,XP(3)+1.)
 555       FF3=BETA_LHA(XP(5),ETA4+1.)+XP(20)*BETA_LHA(XP(5)+1.,ETA4+1.)+
 556      XXP(24)*BETA_LHA(XP(5)+0.5,ETA4+1.)
 557       FF4=BETA_LHA(XP(5)+1.,ETA4+1.)+XP(20)*BETA_LHA(XP(5)+2.,ETA4+1.)+
 558      XXP(24)*BETA_LHA(XP(5)+1.5,ETA4+1.)
 559       COEFU=2.*XP(4)/FF1
 560       COEFD=   XP(4)/FF3
 561 c          print *,'coefu ',coefu
 562 c          print *,'coefd ',coefd
 563       UV=coefu*X**XP(2)*(1.-X)**XP(3)*(1.+XP(16)*X+XP(23)*SQRT(X))
 564       DV=coefd*X**XP(5)*(1.-X)**ETA4*(1.+XP(20)*X+XP(24)*SQRT(X))
 565       FGDIS=al*CF*(-9.-2.*PI2/3.+alog(1.-x)*(-3.+
 566      .2.*alog(1.-x)))*(UV+DV)
 567
 568       DO 23 M=1,NTERMS
 569       Y=0.5*(1.-X)*XI(M)+0.5*(1.+X)
 570       XY=X/Y
 571       UVXY=coefu*XY**XP(2)*(1.-XY)**XP(3)*(1.+XP(16)*XY
 572      .+XP(23)*SQRT(XY))
 573       DVXY=coefd*XY**XP(5)*(1.-XY)**ETA4*(1.+XP(20)*XY
 574      .+XP(24)*SQRT(XY))
 575       AL1=ALOG(1.-Y)
 576       C22=CF*(6.+4.*Y-2.*(1.+Y*Y)/(1.-Y)*ALOG(Y)-2.*(1.+Y)*ALOG(1.-Y))
 577       C23=CF*(-3.+4.*ALOG(1.-Y))/(1.-Y)
 578
 579       FGDIS=FGDIS+.5*(1.-X)*WI(M)*al*
 580      .(C22*(uvxy+dvxy)+C23*(uvxy+dvxy-uv-dv))
 581
 582    23 CONTINUE
 583
 584       return
 585       end