File: BESS.FC of Tape: Various/ETH/fc1

(.FC,.FO Focal format converted to 'WRITE' listing) 

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C-OS/8 FOCAL, 1972

01.01 C BESSEL FUNCTIONS
01.05 A !,"ORDER [N1]",N1
01.10 A !,"NUMBER OF TERMS N",N
01.20 A !,"ARGUMENT Z",Z;S Z=Z/2
01.30 S  B=-Z*Z
01.35 S N0=0
01.40 S S=1;S P=1
01.50 F K=1,N;S P=P*B/(K*(N0+K));S S=S+P
01.60 S B1=Z^N0*S
01.65 S B0=B1;S N0=1;D 1.4;D 1.5;D 1.6
01.70 I (N1-2)1.9;F I=1,N1-1;S B2=I*B1/Z-B0;S B0=B1;S B1=B2
01.90 I (N1),1.95;S B0=B1
01.95 T !,%8.06,"J[N1](Z)=",B0;G 1.2

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