24 lines
518 B
Fortran
24 lines
518 B
Fortran
FUNCTION gasdev(idum)
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INTEGER idum
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REAL gasdev
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CU USES ran1
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INTEGER iset
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REAL fac,gset,rsq,v1,v2,ran1
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SAVE iset,gset
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DATA iset/0/
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if (iset.eq.0) then
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1 v1=2.*ran1(idum)-1.
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v2=2.*ran1(idum)-1.
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rsq=v1**2+v2**2
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if(rsq.ge.1..or.rsq.eq.0.)goto 1
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fac=sqrt(-2.*log(rsq)/rsq)
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gset=v1*fac
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gasdev=v2*fac
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iset=1
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else
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gasdev=gset
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iset=0
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endif
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return
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END
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