yaole
38 lines
998 B
Python
38 lines
998 B
Python
import math
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def loggam(x):
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# double x0, x2, xp, gl, gl0;
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# long k, n;
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a = [8.333333333333333e-02, -2.777777777777778e-03,
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7.936507936507937e-04, -5.952380952380952e-04,
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8.417508417508418e-04, -1.917526917526918e-03,
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6.410256410256410e-03, -2.955065359477124e-02,
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1.796443723688307e-01, -1.39243221690590e+00]
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x *= 1.0
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x0 = x
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n = 0
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if x == 1.0 or x == 2.0:
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return 0.0
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elif x <= 7.0:
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n = int(7 - x)
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x0 = x + n
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x2 = 1.0 / (x0*x0)
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xp = 2 * math.pi
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gl0 = a[9]
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for k in range(8, -1, -1):
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gl0 *= x2
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gl0 += a[k]
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gl = gl0/x0 + 0.5 * math.log(xp) + (x0-0.5) * math.log(x0) - x0
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if x <= 7.0:
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for k in range(1, n + 1):
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gl -= math.log(x0-1.0)
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x0 -= 1.0
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return gl
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print(loggam(2))
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print(loggam(3))
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print(loggam(4))
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print(loggam(5)) |