19 lines
393 B
Fortran
19 lines
393 B
Fortran
FUNCTION bessk(n,x)
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INTEGER n
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REAL bessk,x
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CU USES bessk0,bessk1
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INTEGER j
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REAL bk,bkm,bkp,tox,bessk0,bessk1
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if (n.lt.2) pause 'bad argument n in bessk'
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tox=2.0/x
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bkm=bessk0(x)
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bk=bessk1(x)
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do 11 j=1,n-1
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bkp=bkm+j*tox*bk
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bkm=bk
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bk=bkp
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11 continue
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bessk=bk
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return
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END
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