19 lines
390 B
Fortran
19 lines
390 B
Fortran
FUNCTION bessy(n,x)
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INTEGER n
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REAL bessy,x
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CU USES bessy0,bessy1
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INTEGER j
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REAL by,bym,byp,tox,bessy0,bessy1
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if(n.lt.2)pause 'bad argument n in bessy'
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tox=2./x
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by=bessy1(x)
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bym=bessy0(x)
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do 11 j=1,n-1
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byp=j*tox*by-bym
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bym=by
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by=byp
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11 continue
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bessy=by
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return
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END
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