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pyctq2.F
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1  FUNCTION pyctq2 (Iset, Iprt, X, Q)
2 
3 C...This routine gives the CTEQ 2 parton distribution function sets in
4 C...parametrized form. It is adapted from the revised parametrization
5 C...with extended range of November 12, 1993.
6 C...Authors: J. Botts, H.L. Lai, J.G. Morfin, J.F. Owens, J. Qiu,
7 C...W.K. Tung and H. Weerts.
8  common/ludat2/kchg(500,3),pmas(500,4),parf(2000),vckm(4,4)
9  SAVE /ludat2/
10 
11 C...Data on Lambda values of fits, minimum Q and quark masses.
12  dimension alm(6), qms(4:6)
13  DATA alm / 0.213, 0.208, 0.208, 0.322, 0.190, 0.235 /
14  DATA qmn / 1.60 /, (qms(i), i=4,6) / 1.60, 5.00, 180.0 /
15  qms(6) = pmas(6,1)
16 
17 C....Check flavour thresholds. Set up Qi for SB.
18  ip = iabs(iprt)
19  If (ip .GE. 4) then
20  If (q .LE. qms(ip)) then
21  pyctq2 = 0.0
22  Return
23  Endif
24  qi = qms(ip)
25  Else
26  qi = qmn
27  Endif
28 
29 C...Use "standard lambda" of parametrization program for expansion.
30  alam = alm(iset)
31  sbl = log(q/alam) / log(qi/alam)
32  sb = log(sbl)
33  sb2 = sb*sb
34  sb3 = sb2*sb
35 
36 C...Expansion for run le26 - CTEQ2M
37  If (iset .EQ. 1) then
38  If (iprt .EQ. 2) then
39  a0=exp( 0.2143e+00+0.8417e+00*sb -0.2451e+01*sb2+0.9875e+00*sb3)
40  a1= 0.5209e+00-0.2384e+00*sb +0.5086e+00*sb2-0.2123e+00*sb3
41  a2= 0.3178e+01+0.5258e+01*sb -0.8102e+01*sb2+0.3334e+01*sb3
42  a3=-0.8537e+00+0.5921e+01*sb -0.1007e+02*sb2+0.4146e+01*sb3
43  a4= 0.1821e+01+0.2822e-01*sb +0.1662e+00*sb2-0.1058e+00*sb3
44  a5= 0.0000e+00-0.1090e+01*sb +0.3136e+01*sb2-0.1301e+01*sb3
45  Elseif (iprt .EQ. 1) then
46  a0=exp(-0.1314e+01-0.1342e-01*sb +0.1136e+00*sb2-0.1557e+00*sb3)
47  a1= 0.2780e+00+0.2558e-01*sb +0.4467e-02*sb2-0.2472e-02*sb3
48  a2= 0.3672e+01+0.5324e+00*sb +0.3531e-01*sb2+0.7928e-03*sb3
49  a3= 0.2957e+02-0.2000e+02*sb +0.5929e+01*sb2+0.3390e+00*sb3
50  a4= 0.8069e+00-0.2877e+00*sb +0.3574e-01*sb2+0.5622e-02*sb3
51  a5= 0.0000e+00+0.2287e+00*sb -0.4052e-01*sb2+0.5589e-01*sb3
52  Elseif (iprt .EQ. 0) then
53  a0=exp(-0.1059e+00-0.1461e+01*sb -0.2544e+00*sb2+0.4526e-01*sb3)
54  a1=-0.2578e+00+0.1385e+00*sb -0.1383e+00*sb2+0.3811e-01*sb3
55  a2= 0.5195e+01+0.9648e+00*sb -0.2103e+00*sb2-0.6701e-01*sb3
56  a3= 0.5131e+01+0.2151e+01*sb -0.2880e+01*sb2+0.6608e+00*sb3
57  a4= 0.1118e+01+0.2636e+00*sb -0.5140e+00*sb2+0.1613e+00*sb3
58  a5= 0.0000e+00+0.2456e+01*sb -0.8741e+00*sb2+0.2136e+00*sb3
59  Elseif (iprt .EQ. -1) then
60  a0=exp(-0.2732e+00-0.3523e+01*sb +0.3657e+01*sb2-0.1415e+01*sb3)
61  a1=-0.3807e+00+0.1211e+00*sb -0.1231e+00*sb2+0.3753e-01*sb3
62  a2= 0.9698e+01-0.2596e+01*sb +0.2412e+01*sb2-0.9257e+00*sb3
63  a3=-0.6165e+00+0.1120e+01*sb -0.1708e+01*sb2+0.6383e+00*sb3
64  a4= 0.7292e-01-0.1339e+00*sb +0.2104e+00*sb2-0.7987e-01*sb3
65  a5=-0.1370e+01+0.2452e+01*sb -0.1804e+01*sb2+0.6459e+00*sb3
66  Elseif (iprt .EQ. -2) then
67  a0=exp(-0.2319e+01-0.3182e+01*sb +0.3572e+01*sb2-0.1431e+01*sb3)
68  a1=-0.2622e+00+0.3085e+00*sb -0.4394e+00*sb2+0.1496e+00*sb3
69  a2= 0.9481e+01-0.3627e+01*sb +0.5640e+01*sb2-0.2265e+01*sb3
70  a3= 0.5000e+02-0.1851e+02*sb +0.2640e+01*sb2-0.6001e+00*sb3
71  a4= 0.1566e+01-0.7375e+00*sb +0.8736e+00*sb2-0.3449e+00*sb3
72  a5=-0.7983e-01+0.3236e+01*sb -0.3373e+01*sb2+0.1236e+01*sb3
73  Elseif (iprt .EQ. -3) then
74  a0=exp(-0.1855e+01-0.5302e+01*sb +0.8433e+00*sb2-0.1236e+00*sb3)
75  a1=-0.4000e-02-0.1345e+01*sb +0.1192e+01*sb2-0.3039e+00*sb3
76  a2= 0.6870e+01+0.1246e+01*sb -0.8968e+00*sb2-0.9791e-01*sb3
77  a3= 0.0000e+00+0.4616e+01*sb +0.1026e+02*sb2+0.2844e+02*sb3
78  a4= 0.1000e-02+0.4098e+00*sb -0.4250e+00*sb2+0.1100e+00*sb3
79  a5= 0.0000e+00-0.2151e+01*sb +0.2991e+01*sb2-0.7717e+00*sb3
80  Elseif (iprt .EQ. -4) then
81  a0=sb** 0.7722e+00*exp(-0.7241e+01-0.7885e-01*sb -0.1124e+01*sb2)
82  a1=-0.3971e+00+0.9132e+00*sb -0.1175e+01*sb2+0.3573e+00*sb3
83  a2= 0.6367e+01-0.6565e+01*sb +0.8114e+01*sb2-0.2666e+01*sb3
84  a3= 0.2878e+02-0.2000e+02*sb +0.7000e+00*sb2+0.3000e+02*sb3
85  a4= 0.1010e+00-0.4592e+00*sb +0.5877e+00*sb2-0.1472e+00*sb3
86  a5= 0.1749e+00+0.3875e+01*sb -0.3768e+01*sb2+0.1316e+01*sb3
87  Elseif (iprt .EQ. -5) then
88  a0=sb** 0.1299e+00*exp(-0.4868e+01-0.4339e+01*sb +0.7080e+00*sb2)
89  a1=-0.1705e+00-0.3381e+00*sb +0.5287e+00*sb2-0.2644e+00*sb3
90  a2= 0.5610e+01-0.1365e+01*sb +0.1835e+01*sb2-0.5655e+00*sb3
91  a3=-0.1001e+01+0.3044e+01*sb +0.2680e+01*sb2+0.1426e+02*sb3
92  a4= 0.3814e-02+0.3430e+00*sb -0.6926e+00*sb2+0.3486e+00*sb3
93  a5= 0.1156e+01+0.2016e+01*sb -0.1674e+01*sb2+0.5981e+00*sb3
94  Elseif (iprt .EQ. -6) then
95  a0=sb** 0.9819e+00*exp(-0.7859e+01+0.6819e+00*sb -0.3386e+01*sb2)
96  a1=-0.1055e+00-0.1413e+01*sb +0.3451e+01*sb2-0.2466e+01*sb3
97  a2= 0.4055e+01+0.8107e+01*sb -0.1576e+02*sb2+0.8094e+01*sb3
98  a3= 0.3799e+01+0.9616e+01*sb -0.1984e+02*sb2+0.2641e+02*sb3
99  a4= 0.3619e+00-0.8627e+00*sb -0.9390e-01*sb2+0.9196e+00*sb3
100  a5= 0.3779e+01-0.6073e+01*sb +0.9999e+01*sb2-0.4304e+01*sb3
101  Endif
102 
103 C...Expansion for run sa17 - CTEQ2MS
104  Elseif (iset .EQ. 2) then
105  If (iprt .EQ. 2) then
106  a0=exp( 0.2790e+00+0.7294e+00*sb -0.2202e+01*sb2+0.8599e+00*sb3)
107  a1= 0.5380e+00-0.2261e+00*sb +0.4636e+00*sb2-0.1871e+00*sb3
108  a2= 0.3259e+01+0.2141e+01*sb -0.2947e+01*sb2+0.1245e+01*sb3
109  a3=-0.8390e+00+0.1448e+01*sb -0.2331e+01*sb2+0.8658e+00*sb3
110  a4= 0.1847e+01-0.3943e+01*sb +0.5998e+01*sb2-0.2191e+01*sb3
111  a5= 0.0000e+00-0.9719e+00*sb +0.2830e+01*sb2-0.1137e+01*sb3
112  Elseif (iprt .EQ. 1) then
113  a0=exp(-0.1318e+01+0.2328e-01*sb +0.5179e-01*sb2-0.1305e+00*sb3)
114  a1= 0.2760e+00+0.4429e-01*sb -0.2626e-01*sb2+0.7143e-02*sb3
115  a2= 0.3660e+01+0.5232e+00*sb +0.5491e-01*sb2-0.4115e-02*sb3
116  a3= 0.2910e+02-0.2000e+02*sb +0.6631e+01*sb2-0.3050e-01*sb3
117  a4= 0.8010e+00-0.2688e+00*sb +0.1051e-01*sb2+0.1195e-01*sb3
118  a5= 0.0000e+00+0.2887e+00*sb -0.1398e+00*sb2+0.8194e-01*sb3
119  Elseif (iprt .EQ. 0) then
120  a0=exp(-0.1623e+01-0.7232e+00*sb +0.1889e+00*sb2+0.1140e+00*sb3)
121  a1=-0.5000e+00+0.8611e-01*sb +0.2203e-01*sb2-0.1401e-01*sb3
122  a2= 0.3821e+01+0.8976e+00*sb +0.1400e+00*sb2-0.9163e-01*sb3
123  a3= 0.5809e+01-0.5060e+01*sb +0.3808e+00*sb2+0.2519e+00*sb3
124  a4= 0.4500e+00-0.5121e+00*sb +0.1979e+00*sb2-0.2705e-01*sb3
125  a5= 0.0000e+00+0.1210e+01*sb -0.2921e+00*sb2+0.1240e+00*sb3
126  Elseif (iprt .EQ. -1) then
127  a0=exp(-0.6986e-01-0.5954e+00*sb -0.1582e+01*sb2+0.5104e+00*sb3)
128  a1=-0.8461e+00+0.2127e+00*sb +0.9425e-01*sb2-0.5264e-01*sb3
129  a2= 0.1200e+02+0.1659e+01*sb -0.5354e+01*sb2+0.1795e+01*sb3
130  a3= 0.2958e+02+0.3000e+02*sb +0.3000e+02*sb2-0.1965e+02*sb3
131  a4= 0.4000e+01-0.4865e+00*sb +0.9460e+00*sb2+0.3432e+00*sb3
132  a5=-0.3378e+01+0.1656e+01*sb +0.1123e+01*sb2-0.4667e+00*sb3
133  Elseif (iprt .EQ. -2) then
134  a0=exp(-0.1929e+01-0.2626e+01*sb +0.2926e+01*sb2-0.1297e+01*sb3)
135  a1=-0.6627e+00+0.4561e+00*sb -0.3818e+00*sb2+0.1239e+00*sb3
136  a2= 0.9506e+01-0.2724e+01*sb +0.4283e+01*sb2-0.1804e+01*sb3
137  a3= 0.1897e+02+0.1642e+01*sb -0.8390e+01*sb2+0.3894e+01*sb3
138  a4= 0.1024e+01-0.1786e+00*sb +0.4535e+00*sb2-0.2075e+00*sb3
139  a5=-0.1746e+01+0.3572e+01*sb -0.2908e+01*sb2+0.1093e+01*sb3
140  Elseif (iprt .EQ. -3) then
141  a0=exp(-0.4913e+00-0.6866e+01*sb +0.1432e+01*sb2-0.1749e+00*sb3)
142  a1=-0.1157e+00-0.1567e+01*sb +0.1439e+01*sb2-0.3724e+00*sb3
143  a2= 0.7730e+01+0.9748e+00*sb -0.1157e+01*sb2-0.8358e-02*sb3
144  a3=-0.6050e+00+0.1835e+01*sb +0.3788e+01*sb2+0.3000e+02*sb3
145  a4= 0.1620e-08+0.4590e+00*sb -0.4070e+00*sb2+0.8900e-01*sb3
146  a5=-0.7048e+00-0.2505e+01*sb +0.4000e+01*sb2-0.1161e+01*sb3
147  Elseif (iprt .EQ. -4) then
148  a0=sb** 0.7393e+00*exp(-0.6518e+01-0.3998e+00*sb -0.1111e+01*sb2)
149  a1=-0.6482e+00+0.1125e+01*sb -0.1290e+01*sb2+0.3940e+00*sb3
150  a2= 0.8487e+01-0.9235e+01*sb +0.9353e+01*sb2-0.2913e+01*sb3
151  a3= 0.2265e+02-0.1999e+02*sb +0.4105e+01*sb2+0.2144e+02*sb3
152  a4= 0.8990e-01-0.4372e+00*sb +0.5941e+00*sb2-0.1469e+00*sb3
153  a5=-0.9690e+00+0.5068e+01*sb -0.4368e+01*sb2+0.1503e+01*sb3
154  Elseif (iprt .EQ. -5) then
155  a0=sb** 0.9880e+00*exp(-0.7180e+01-0.2494e+01*sb +0.3561e-01*sb2)
156  a1=-0.4301e+00-0.2611e+00*sb +0.3914e+00*sb2-0.1638e+00*sb3
157  a2= 0.5137e+01+0.1506e+01*sb -0.9588e+00*sb2-0.1596e+00*sb3
158  a3= 0.1483e+02+0.2998e+02*sb +0.2357e+02*sb2-0.9353e+01*sb3
159  a4= 0.2426e+00+0.1371e+00*sb -0.3791e+00*sb2+0.1948e+00*sb3
160  a5= 0.1463e+01+0.1907e+00*sb +0.3557e+00*sb2+0.2097e-01*sb3
161  Elseif (iprt .EQ. -6) then
162  a0=sb** 0.1005e+01*exp(-0.5255e+01-0.9866e-01*sb -0.2737e+01*sb2)
163  a1=-0.3140e+00-0.2055e+00*sb +0.5594e+00*sb2-0.2960e+00*sb3
164  a2= 0.9227e+01-0.4569e+01*sb -0.9724e+01*sb2+0.1026e+02*sb3
165  a3= 0.1131e+02-0.1972e+02*sb -0.1107e+02*sb2+0.2311e+02*sb3
166  a4= 0.1488e+01+0.1737e+01*sb +0.4323e+01*sb2-0.9925e+01*sb3
167  a5= 0.1895e+01-0.7350e+00*sb +0.3780e+01*sb2-0.1408e+01*sb3
168  Endif
169 
170  Elseif (iset .EQ. 3) then
171 C...Expansion for run fa06 - CTEQ2MF
172  If (iprt .EQ. 2) then
173  a0=exp(-0.7913e+00-0.2789e+01*sb -0.7289e-01*sb2+0.1770e+00*sb3)
174  a1= 0.4942e+00-0.7886e-01*sb +0.9057e-01*sb2-0.5259e-01*sb3
175  a2= 0.3727e+01+0.1089e+01*sb -0.1004e+01*sb2+0.4345e+00*sb3
176  a3= 0.1944e+01+0.7846e+01*sb +0.7984e+01*sb2+0.5548e+01*sb3
177  a4= 0.2940e-02+0.8428e-04*sb +0.1266e+00*sb2-0.3517e-01*sb3
178  a5=-0.1060e+00-0.1192e-01*sb +0.1130e+01*sb2-0.4527e+00*sb3
179  Elseif (iprt .EQ. 1) then
180  a0=exp(-0.1344e+01+0.7859e-02*sb +0.4623e-01*sb2-0.1273e+00*sb3)
181  a1= 0.2760e+00+0.4201e-01*sb -0.1795e-01*sb2+0.3212e-02*sb3
182  a2= 0.3660e+01+0.5247e+00*sb +0.4405e-01*sb2+0.1391e-02*sb3
183  a3= 0.2981e+02-0.2000e+02*sb +0.6566e+01*sb2+0.2479e-01*sb3
184  a4= 0.7950e+00-0.2732e+00*sb +0.2470e-01*sb2+0.6157e-02*sb3
185  a5= 0.0000e+00+0.2793e+00*sb -0.9197e-01*sb2+0.5953e-01*sb3
186  Elseif (iprt .EQ. 0) then
187  a0=exp( 0.9746e+00-0.3252e+01*sb +0.1664e+01*sb2-0.6410e+00*sb3)
188  a1=-0.5271e-02-0.3198e+00*sb +0.1279e+00*sb2-0.1256e-02*sb3
189  a2= 0.5740e+01-0.3139e+01*sb +0.3841e+01*sb2-0.1415e+01*sb3
190  a3= 0.7161e-01-0.4363e+01*sb +0.4925e+01*sb2-0.1614e+01*sb3
191  a4= 0.1860e+01+0.1342e+01*sb -0.2234e+01*sb2+0.1047e+01*sb3
192  a5= 0.7409e-01+0.2390e+01*sb -0.1457e+01*sb2+0.5853e+00*sb3
193  Elseif (iprt .EQ. -1) then
194  a0=exp(-0.8454e+00-0.3334e+01*sb +0.3591e+01*sb2-0.1485e+01*sb3)
195  a1=-0.2826e-02-0.2810e+00*sb -0.3809e-01*sb2+0.6585e-01*sb3
196  a2= 0.9139e+01-0.2811e+01*sb +0.4730e+01*sb2-0.2157e+01*sb3
197  a3=-0.3120e+00+0.1217e+01*sb -0.1726e+01*sb2+0.6220e+00*sb3
198  a4= 0.1793e-01-0.4608e-01*sb +0.5294e-01*sb2-0.1709e-01*sb3
199  a5=-0.1471e+00+0.1104e+01*sb -0.1358e+01*sb2+0.7200e+00*sb3
200  Elseif (iprt .EQ. -2) then
201  a0=exp(-0.1398e+01-0.3536e+01*sb +0.3849e+01*sb2-0.1549e+01*sb3)
202  a1=-0.1332e-01-0.2155e-01*sb -0.3404e+00*sb2+0.1569e+00*sb3
203  a2= 0.9981e+01-0.3499e+01*sb +0.5448e+01*sb2-0.2198e+01*sb3
204  a3= 0.3736e+02-0.2000e+02*sb +0.6675e+01*sb2-0.7276e+00*sb3
205  a4= 0.1705e+01-0.1013e+01*sb +0.1122e+01*sb2-0.4057e+00*sb3
206  a5=-0.1189e-01+0.2698e+01*sb -0.3429e+01*sb2+0.1389e+01*sb3
207  Elseif (iprt .EQ. -3) then
208  a0=exp(-0.2979e+01-0.6085e+01*sb +0.2428e+01*sb2-0.6482e+00*sb3)
209  a1=-0.1372e+00-0.1281e+00*sb +0.1587e+00*sb2-0.9637e-01*sb3
210  a2= 0.7009e+01-0.1609e+01*sb +0.2765e+01*sb2-0.1177e+01*sb3
211  a3= 0.1308e+01+0.9583e+01*sb +0.2360e+02*sb2+0.2999e+02*sb3
212  a4= 0.2509e-01+0.2106e+00*sb -0.4405e+00*sb2+0.2075e+00*sb3
213  a5=-0.2069e-01+0.1971e+01*sb -0.1615e+01*sb2+0.6039e+00*sb3
214  Elseif (iprt .EQ. -4) then
215  a0=sb** 0.8072e+00*exp(-0.6920e+01-0.5031e+00*sb -0.9965e+00*sb2)
216  a1=-0.2118e+00+0.7930e+00*sb -0.1101e+01*sb2+0.3302e+00*sb3
217  a2= 0.8039e+01-0.7170e+01*sb +0.8657e+01*sb2-0.2893e+01*sb3
218  a3= 0.2926e+02-0.1993e+02*sb +0.1841e+01*sb2+0.2996e+02*sb3
219  a4= 0.1339e+00-0.5531e+00*sb +0.6505e+00*sb2-0.1595e+00*sb3
220  a5= 0.7439e+00+0.3307e+01*sb -0.3284e+01*sb2+0.1152e+01*sb3
221  Elseif (iprt .EQ. -5) then
222  a0=sb** 0.9925e+00*exp(-0.2190e+01-0.3393e+01*sb -0.8631e+00*sb2)
223  a1=-0.1261e+00-0.2368e+00*sb +0.4143e+00*sb2-0.1577e+00*sb3
224  a2= 0.4585e+01+0.5227e+01*sb -0.3248e+01*sb2-0.2599e+00*sb3
225  a3=-0.1094e+01+0.4927e+00*sb -0.9921e+00*sb2+0.3138e+01*sb3
226  a4= 0.1396e+00+0.2562e+00*sb +0.1844e+00*sb2-0.1599e+00*sb3
227  a5= 0.8621e+00+0.4715e+00*sb +0.2547e+01*sb2-0.8429e+00*sb3
228  Elseif (iprt .EQ. -6) then
229  a0=sb** 0.1016e+01*exp(-0.5397e+01-0.1979e+01*sb -0.2441e+00*sb2)
230  a1=-0.1426e+00-0.2861e+00*sb +0.7434e+00*sb2-0.5214e+00*sb3
231  a2= 0.6363e+01+0.4028e+00*sb -0.8356e+01*sb2+0.6814e+01*sb3
232  a3=-0.2526e+00+0.2425e+01*sb -0.1407e+02*sb2+0.3000e+02*sb3
233  a4= 0.1125e+00-0.1089e+01*sb +0.9977e+01*sb2+0.1000e+02*sb3
234  a5= 0.2669e+01-0.6366e+00*sb +0.4355e+01*sb2-0.2919e+01*sb3
235  Endif
236 
237  Elseif (iset .EQ. 4) then
238 C...Expansion for run ll25 - CTEQ2ML
239  If (iprt .EQ. 2) then
240  a0=exp( 0.3760e+00+0.5491e+00*sb -0.1845e+01*sb2+0.6803e+00*sb3)
241  a1= 0.5650e+00-0.1953e+00*sb +0.3761e+00*sb2-0.1419e+00*sb3
242  a2= 0.3464e+01+0.3817e+01*sb -0.5384e+01*sb2+0.2057e+01*sb3
243  a3=-0.5850e+00+0.5566e+01*sb -0.9000e+01*sb2+0.3433e+01*sb3
244  a4= 0.2322e+01-0.1431e+00*sb +0.3901e+00*sb2-0.1678e+00*sb3
245  a5= 0.0000e+00-0.7370e+00*sb +0.2310e+01*sb2-0.8743e+00*sb3
246  Elseif (iprt .EQ. 1) then
247  a0=exp(-0.1324e+01+0.1169e-01*sb +0.1969e-01*sb2-0.7583e-01*sb3)
248  a1= 0.2890e+00+0.5832e-01*sb -0.2921e-01*sb2+0.4701e-02*sb3
249  a2= 0.3580e+01+0.5291e+00*sb -0.5662e-02*sb2+0.2746e-01*sb3
250  a3= 0.3021e+02-0.1999e+02*sb +0.6250e+01*sb2-0.3035e+00*sb3
251  a4= 0.7990e+00-0.2531e+00*sb +0.5556e-02*sb2+0.8272e-02*sb3
252  a5= 0.0000e+00+0.3674e+00*sb -0.1383e+00*sb2+0.4665e-01*sb3
253  Elseif (iprt .EQ. 0) then
254  a0=exp(-0.1920e+00-0.7015e+00*sb -0.9113e+00*sb2+0.2352e+00*sb3)
255  a1=-0.2120e+00+0.1133e-01*sb -0.1553e-01*sb2+0.2822e-02*sb3
256  a2= 0.4549e+01+0.1250e+01*sb -0.4647e+00*sb2+0.9617e-01*sb3
257  a3= 0.1197e+02-0.4156e+01*sb +0.1413e+00*sb2+0.1607e+00*sb3
258  a4= 0.1616e+01+0.1082e+00*sb -0.6651e+00*sb2+0.2356e+00*sb3
259  a5= 0.0000e+00+0.1824e+01*sb -0.2063e+00*sb2+0.1148e-01*sb3
260  Elseif (iprt .EQ. -1) then
261  a0=exp(-0.1388e+01-0.7408e+00*sb -0.6454e+00*sb2+0.2373e+00*sb3)
262  a1=-0.2928e+00-0.1726e-01*sb +0.4033e-01*sb2-0.2514e-01*sb3
263  a2= 0.9975e+01-0.2048e+01*sb -0.6060e+00*sb2+0.5225e+00*sb3
264  a3= 0.2687e+02-0.4683e+01*sb -0.1999e+02*sb2+0.1188e+02*sb3
265  a4= 0.4000e+01-0.6773e+00*sb +0.4301e+00*sb2+0.4524e+00*sb3
266  a5=-0.7164e+00+0.7488e+00*sb +0.5766e+00*sb2-0.2609e+00*sb3
267  Elseif (iprt .EQ. -2) then
268  a0=exp(-0.2272e+01-0.2998e+01*sb +0.3282e+01*sb2-0.1203e+01*sb3)
269  a1=-0.2062e+00+0.3320e+00*sb -0.5074e+00*sb2+0.1655e+00*sb3
270  a2= 0.9667e+01-0.3497e+01*sb +0.5271e+01*sb2-0.1984e+01*sb3
271  a3= 0.4996e+02-0.3241e+01*sb -0.1425e+02*sb2+0.3849e+01*sb3
272  a4= 0.1619e+01-0.5354e+00*sb +0.5753e+00*sb2-0.2238e+00*sb3
273  a5= 0.8755e-01+0.3195e+01*sb -0.3496e+01*sb2+0.1197e+01*sb3
274  Elseif (iprt .EQ. -3) then
275  a0=exp(-0.1864e+01-0.5258e+01*sb +0.1034e+01*sb2-0.1550e+00*sb3)
276  a1= 0.1000e-02-0.1090e+01*sb +0.8345e+00*sb2-0.1887e+00*sb3
277  a2= 0.6898e+01-0.4951e+00*sb +0.4279e+00*sb2-0.2727e+00*sb3
278  a3= 0.0000e+00+0.4322e+01*sb +0.8181e+01*sb2+0.2309e+02*sb3
279  a4= 0.1000e-02+0.3550e+00*sb -0.3220e+00*sb2+0.7294e-01*sb3
280  a5= 0.0000e+00-0.1347e+01*sb +0.1896e+01*sb2-0.4491e+00*sb3
281  Elseif (iprt .EQ. -4) then
282  a0=sb** 0.7528e+00*exp(-0.7684e+01+0.6791e-01*sb -0.9094e+00*sb2)
283  a1=-0.3732e+00+0.8408e+00*sb -0.1020e+01*sb2+0.3046e+00*sb3
284  a2= 0.4984e+01-0.5534e+01*sb +0.6418e+01*sb2-0.1856e+01*sb3
285  a3= 0.3761e+02-0.1999e+02*sb -0.3358e+01*sb2+0.2999e+02*sb3
286  a4= 0.1161e+00-0.4680e+00*sb +0.5567e+00*sb2-0.1633e+00*sb3
287  a5= 0.3028e+00+0.3339e+01*sb -0.3004e+01*sb2+0.9160e+00*sb3
288  Elseif (iprt .EQ. -5) then
289  a0=sb** 0.1011e+01*exp(-0.7217e+01-0.2288e+01*sb +0.3450e+00*sb2)
290  a1=-0.1955e+00-0.3371e+00*sb +0.5111e+00*sb2-0.2210e+00*sb3
291  a2= 0.4302e+01-0.1214e+01*sb +0.3104e+01*sb2-0.1408e+01*sb3
292  a3= 0.1487e+02+0.1549e+02*sb +0.2875e+02*sb2-0.1922e+02*sb3
293  a4= 0.8935e-02+0.3571e+00*sb -0.6668e+00*sb2+0.3037e+00*sb3
294  a5= 0.1570e+01+0.7105e+00*sb -0.6070e+00*sb2+0.3796e+00*sb3
295  Elseif (iprt .EQ. -6) then
296  a0=sb** 0.9986e+00*exp(-0.5847e+01-0.2798e+00*sb -0.9882e+00*sb2)
297  a1=-0.2154e+00-0.8282e-01*sb +0.3611e-01*sb2+0.2623e-01*sb3
298  a2= 0.3250e+01+0.9635e+01*sb -0.1274e+02*sb2+0.4453e+01*sb3
299  a3=-0.2594e+01+0.9097e+01*sb +0.1581e+02*sb2-0.9123e+01*sb3
300  a4= 0.1768e+01-0.2749e+01*sb +0.9999e+01*sb2+0.9995e+01*sb3
301  a5= 0.2521e+01-0.1802e-01*sb +0.4820e+00*sb2+0.2004e+00*sb3
302  Endif
303 
304  Elseif (iset .EQ. 5) then
305 C...Expansion for run lo24 - CTEQ2L
306  If (iprt .EQ. 2) then
307  a0=exp( 0.7248e-01+0.3941e+00*sb -0.1772e+01*sb2+0.7629e+00*sb3)
308  a1= 0.4964e+00-0.1224e+00*sb +0.3646e+00*sb2-0.1685e+00*sb3
309  a2= 0.3000e+01+0.2780e+01*sb -0.4028e+01*sb2+0.1816e+01*sb3
310  a3=-0.1064e+01+0.3062e+01*sb -0.5927e+01*sb2+0.2785e+01*sb3
311  a4= 0.3193e+01+0.1499e+01*sb -0.2765e+01*sb2+0.1019e+01*sb3
312  a5= 0.1524e-01-0.4541e+00*sb +0.2281e+01*sb2-0.1033e+01*sb3
313  Elseif (iprt .EQ. 1) then
314  a0=exp(-0.1794e+01-0.2055e+00*sb -0.3350e-01*sb2-0.5084e-01*sb3)
315  a1= 0.1748e+00+0.4637e-01*sb -0.2048e-01*sb2+0.2596e-02*sb3
316  a2= 0.3321e+01+0.6253e+00*sb +0.2148e-01*sb2+0.1288e-01*sb3
317  a3= 0.4355e+02-0.2000e+02*sb +0.5486e+01*sb2+0.1536e+00*sb3
318  a4= 0.9586e+00-0.3217e+00*sb +0.4458e-01*sb2-0.1404e-03*sb3
319  a5=-0.6595e-02+0.3499e+00*sb -0.7048e-01*sb2+0.2619e-01*sb3
320  Elseif (iprt .EQ. 0) then
321  a0=exp(-0.6194e+00-0.2643e+00*sb -0.1875e+01*sb2+0.6011e+00*sb3)
322  a1=-0.2600e+00+0.8704e-01*sb -0.7375e-01*sb2+0.1876e-01*sb3
323  a2= 0.4620e+01+0.1578e+01*sb -0.8411e+00*sb2+0.1527e+00*sb3
324  a3= 0.1604e+02-0.1230e+02*sb +0.6939e+01*sb2-0.2012e+01*sb3
325  a4= 0.1255e+01+0.4769e+00*sb -0.9915e+00*sb2+0.3439e+00*sb3
326  a5= 0.1116e-02+0.2409e+01*sb -0.4442e+00*sb2+0.3431e-01*sb3
327  Elseif (iprt .EQ. -1) then
328  a0=exp(-0.1571e+01-0.1905e+00*sb -0.8672e+00*sb2+0.2070e+00*sb3)
329  a1=-0.3266e+00+0.6428e-01*sb -0.8694e-01*sb2+0.1778e-01*sb3
330  a2= 0.8921e+01-0.5010e+00*sb -0.9658e+00*sb2+0.3893e+00*sb3
331  a3= 0.1329e+02+0.4652e+01*sb -0.2000e+02*sb2+0.1001e+02*sb3
332  a4= 0.3283e+01-0.3400e+00*sb -0.1957e+00*sb2+0.8063e+00*sb3
333  a5=-0.5701e+00+0.4042e+00*sb +0.5239e+00*sb2-0.1665e+00*sb3
334  Elseif (iprt .EQ. -2) then
335  a0=exp(-0.2281e+01-0.2768e+01*sb +0.3137e+01*sb2-0.1278e+01*sb3)
336  a1=-0.2624e+00+0.4142e+00*sb -0.5936e+00*sb2+0.1937e+00*sb3
337  a2= 0.9438e+01-0.3179e+01*sb +0.5107e+01*sb2-0.2179e+01*sb3
338  a3= 0.5000e+02-0.1802e+02*sb -0.7515e+01*sb2+0.2991e+01*sb3
339  a4= 0.1809e+01-0.9121e+00*sb +0.8854e+00*sb2-0.3582e+00*sb3
340  a5= 0.4056e-01+0.3033e+01*sb -0.3431e+01*sb2+0.1253e+01*sb3
341  Elseif (iprt .EQ. -3) then
342  a0=exp(-0.2318e+01-0.4104e+01*sb -0.1502e+00*sb2+0.1693e+00*sb3)
343  a1=-0.2251e-01-0.1101e+01*sb +0.1037e+01*sb2-0.3290e+00*sb3
344  a2= 0.6989e+01+0.1794e+01*sb -0.1811e+01*sb2+0.3061e+00*sb3
345  a3= 0.7972e+00+0.7806e+01*sb +0.1869e+02*sb2+0.2999e+02*sb3
346  a4= 0.4795e-01+0.1622e+00*sb -0.3977e+00*sb2+0.1920e+00*sb3
347  a5=-0.5275e-01-0.2616e+01*sb +0.3076e+01*sb2-0.7425e+00*sb3
348  Elseif (iprt .EQ. -4) then
349  a0=sb** 0.8431e+00*exp(-0.6539e+01-0.1875e+00*sb -0.1346e+01*sb2)
350  a1=-0.4970e+00+0.9062e+00*sb -0.1169e+01*sb2+0.3703e+00*sb3
351  a2= 0.4939e+01-0.2995e+01*sb +0.4483e+01*sb2-0.1704e+01*sb3
352  a3= 0.3113e+02-0.1997e+02*sb +0.1540e+01*sb2+0.3000e+02*sb3
353  a4= 0.1349e+00-0.5418e+00*sb +0.6142e+00*sb2-0.1360e+00*sb3
354  a5=-0.8590e+00+0.3956e+01*sb -0.3612e+01*sb2+0.1401e+01*sb3
355  Elseif (iprt .EQ. -5) then
356  a0=sb** 0.2639e-01*exp(-0.2099e+01-0.2681e+01*sb +0.2925e+00*sb2)
357  a1=-0.2243e+00-0.5343e-01*sb -0.1953e-01*sb2+0.1586e-01*sb3
358  a2= 0.4294e+01+0.1102e+01*sb -0.1822e+00*sb2-0.2481e+00*sb3
359  a3=-0.9998e+00+0.8275e-01*sb +0.5494e+00*sb2-0.1982e+00*sb3
360  a4= 0.5904e-04+0.9222e-01*sb -0.9293e-01*sb2+0.9159e-01*sb3
361  a5= 0.2657e+00+0.1770e+01*sb -0.7111e+00*sb2+0.2525e+00*sb3
362  Elseif (iprt .EQ. -6) then
363  a0=sb** 0.1009e+01*exp(-0.7032e+01+0.4562e+01*sb -0.9081e+01*sb2)
364  a1=-0.1412e+00-0.5076e+00*sb +0.9513e+00*sb2-0.4326e+00*sb3
365  a2= 0.5385e+01+0.3023e+01*sb -0.1162e+02*sb2+0.7006e+01*sb3
366  a3= 0.4997e+01-0.1600e+02*sb +0.1342e+02*sb2+0.1197e+02*sb3
367  a4= 0.5825e+00+0.3994e+00*sb -0.1255e+01*sb2+0.6486e+00*sb3
368  a5= 0.3365e+01-0.4026e+01*sb +0.8385e+01*sb2-0.2260e+01*sb3
369  Endif
370 
371  Elseif (iset .EQ. 6) then
372 C...Expansion for run da06 - CTEQ2D
373  If (iprt .EQ. 2) then
374  a0=exp( 0.1590e+00+0.5580e+00*sb -0.1838e+01*sb2+0.7018e+00*sb3)
375  a1= 0.5110e+00-0.1625e+00*sb +0.3547e+00*sb2-0.1412e+00*sb3
376  a2= 0.3158e+01+0.3962e+01*sb -0.5866e+01*sb2+0.2375e+01*sb3
377  a3=-0.6000e+00+0.6144e+01*sb -0.1056e+02*sb2+0.4345e+01*sb3
378  a4= 0.2306e+01-0.4669e-01*sb +0.2711e+00*sb2-0.1640e+00*sb3
379  a5= 0.0000e+00-0.6638e+00*sb +0.2239e+01*sb2-0.8843e+00*sb3
380  Elseif (iprt .EQ. 1) then
381  a0=exp(-0.1182e+01+0.1449e+00*sb +0.2753e-01*sb2-0.1009e+00*sb3)
382  a1= 0.2540e+00+0.2686e-01*sb -0.1546e-01*sb2+0.5396e-02*sb3
383  a2= 0.3442e+01+0.5576e+00*sb +0.1937e-01*sb2+0.6696e-02*sb3
384  a3= 0.2545e+02-0.2000e+02*sb +0.7355e+01*sb2-0.7058e+00*sb3
385  a4= 0.9170e+00-0.3090e+00*sb +0.1705e-01*sb2+0.8534e-02*sb3
386  a5= 0.0000e+00+0.1449e+00*sb -0.7821e-01*sb2+0.6405e-01*sb3
387  Elseif (iprt .EQ. 0) then
388  a0=exp(-0.3410e+00-0.9613e+00*sb -0.4969e+00*sb2+0.9360e-01*sb3)
389  a1=-0.2400e+00+0.1473e+00*sb -0.1593e+00*sb2+0.4538e-01*sb3
390  a2= 0.4841e+01+0.9311e+00*sb +0.1601e-03*sb2-0.1331e+00*sb3
391  a3= 0.7427e+01-0.1397e+01*sb +0.1489e+00*sb2-0.2848e+00*sb3
392  a4= 0.9600e+00+0.3697e+00*sb -0.4246e+00*sb2+0.1032e+00*sb3
393  a5= 0.0000e+00+0.2484e+01*sb -0.9908e+00*sb2+0.2568e+00*sb3
394  Elseif (iprt .EQ. -1) then
395  a0=exp( 0.1176e+00-0.3418e+01*sb +0.3529e+01*sb2-0.1367e+01*sb3)
396  a1=-0.3654e+00+0.1914e+00*sb -0.2192e+00*sb2+0.6933e-01*sb3
397  a2= 0.1099e+02-0.4281e+01*sb +0.3729e+01*sb2-0.1254e+01*sb3
398  a3=-0.7514e+00+0.7696e+00*sb -0.1134e+01*sb2+0.4245e+00*sb3
399  a4= 0.7690e-01-0.6558e-01*sb +0.8726e-01*sb2-0.3345e-01*sb3
400  a5=-0.1447e+01+0.2617e+01*sb -0.2094e+01*sb2+0.7536e+00*sb3
401  Elseif (iprt .EQ. -2) then
402  a0=exp(-0.2412e+01-0.2522e+01*sb +0.3126e+01*sb2-0.1305e+01*sb3)
403  a1=-0.2353e+00+0.3118e+00*sb -0.4864e+00*sb2+0.1689e+00*sb3
404  a2= 0.9017e+01-0.2437e+01*sb +0.4659e+01*sb2-0.2044e+01*sb3
405  a3= 0.5000e+02-0.1158e+02*sb -0.9260e+01*sb2+0.2847e+01*sb3
406  a4= 0.1726e+01-0.6849e+00*sb +0.7864e+00*sb2-0.3300e+00*sb3
407  a5= 0.5080e-01+0.2858e+01*sb -0.3297e+01*sb2+0.1246e+01*sb3
408  Elseif (iprt .EQ. -3) then
409  a0=exp(-0.1966e+01-0.4405e+01*sb +0.2436e+00*sb2+0.4576e-01*sb3)
410  a1=-0.4000e-02-0.1229e+01*sb +0.1118e+01*sb2-0.2988e+00*sb3
411  a2= 0.6902e+01+0.1266e+01*sb -0.1068e+01*sb2+0.3062e-01*sb3
412  a3= 0.0000e+00+0.3987e+01*sb +0.9389e+01*sb2+0.1881e+02*sb3
413  a4= 0.1000e-02+0.3528e+00*sb -0.4201e+00*sb2+0.1248e+00*sb3
414  a5= 0.0000e+00-0.2149e+01*sb +0.2925e+01*sb2-0.7609e+00*sb3
415  Elseif (iprt .EQ. -4) then
416  a0=sb** 0.7561e+00*exp(-0.6960e+01+0.5634e-01*sb -0.1170e+01*sb2)
417  a1=-0.4232e+00+0.9269e+00*sb -0.1161e+01*sb2+0.3470e+00*sb3
418  a2= 0.6057e+01-0.5790e+01*sb +0.7352e+01*sb2-0.2435e+01*sb3
419  a3= 0.2941e+02-0.1999e+02*sb -0.8345e+00*sb2+0.3000e+02*sb3
420  a4= 0.1069e+00-0.4620e+00*sb +0.5614e+00*sb2-0.1336e+00*sb3
421  a5=-0.1865e+00+0.3953e+01*sb -0.3791e+01*sb2+0.1315e+01*sb3
422  Elseif (iprt .EQ. -5) then
423  a0=sb** 0.5661e-02*exp(-0.2123e+01-0.3026e+01*sb +0.1912e+00*sb2)
424  a1=-0.2011e+00-0.1338e-01*sb -0.3974e-01*sb2+0.1948e-01*sb3
425  a2= 0.4906e+01+0.1740e+01*sb -0.1387e+01*sb2+0.1263e+00*sb3
426  a3=-0.1000e+01+0.5767e-01*sb +0.6377e+00*sb2+0.4736e-01*sb3
427  a4= 0.5927e-04+0.1039e+00*sb -0.9797e-01*sb2+0.6881e-01*sb3
428  a5= 0.4017e+00+0.1981e+01*sb -0.7758e+00*sb2+0.2916e+00*sb3
429  Elseif (iprt .EQ. -6) then
430  a0=sb** 0.1008e+01*exp(-0.7211e+01+0.3273e+01*sb -0.6979e+01*sb2)
431  a1=-0.1026e+00-0.4948e+00*sb +0.1188e+01*sb2-0.8016e+00*sb3
432  a2= 0.5397e+01+0.2135e+01*sb -0.9531e+01*sb2+0.6115e+01*sb3
433  a3= 0.4966e+01-0.1111e+02*sb +0.4732e+01*sb2+0.1568e+02*sb3
434  a4= 0.5345e+00-0.1935e+00*sb +0.5816e+00*sb2-0.6794e+00*sb3
435  a5= 0.3569e+01-0.3477e+01*sb +0.8756e+01*sb2-0.4139e+01*sb3
436  Endif
437  Endif
438 
439 C...Calculation of x * f(x, Q).
440  pyctq2 = max(0., a0 *(x**a1) *((1.-x)**a2) *(1.+a3*(x**a4))
441  & *(log(1.+1./x))**a5 )
442 
443  RETURN
444  END