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POFORTRAN IV/66 program stalls in DO loops
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  1. POFORTRAN IV/66 program stalls in DO loops
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    copied!<p>I copied a FORTRAN IV program from a thesis, so it presumably worked at the time it was written. I compiled it with gfortran. When running, it stalls in an integration subroutine. I have tried easing off the residuals but to no avail. I am asking for help because (presuming no mistakes in code) gfortran might not like the archaic 66/IV code, and updating it is outside my abilities.</p> <p>The program gets stuck by line 9, so I wonder if the DO loops are responsible. Note, lines 1 and 6 are unusual to me because ',1' has been added to the ends: e.g. =1,N,1. </p> <p>I don't think it's necessary to show the FUNC subroutine called on line 5 but am happy to provide it if necessary.</p> <p>If you need more detailed information I am happy to provide it.</p> <pre><code>00000001 13 DO 22 TDP=QDP,7,1 00000002 TD=TDP-1 00000003 X=X0+H0 00000004 IF(TD.EQ.QD) GOTO 15 00000005 CALL FUNC(N,DY,X,Y,J) 00000006 15 DO 21 RD=1,N,1 00000007 GOTO (120,121,122,123,124,125,126),TDP 00000008 120 RK(5*N*RD)=Y(RD) 00000009 GOTO 21 00000010 121 RK(RD)=HD*DY(RD) 00000011 H0=0.5*HD 00000012 F0=0.5*RK(RD) 00000013 GOTO 20 00000014 122 RK(N+RD)=HD*DY(RD) 00000015 F0=0.25*(RK(RD)+RK(N+RD)) 00000016 GOTO 20 00000017 123 RK(2*N+RD)=HD*DY(RD) 00000018 H0=HD 00000019 F0=-RK(N+RD)+2.*RK(2*N+RD) 00000020 GOTO 20 00000021 124 RK(3*N+RD)=HD*DY(RD) 00000022 H0=0.66666666667*HD 00000023 F0=(7.*RK(RD)+10.*RK(N+RD)+RK(3*N+RD))/27. 00000024 GOTO 20 00000025 125 RK(4*N+RD)=HD*DY(RD) 00000026 H0=0.2*HD 00000027 F0=(28.*RK(RD)-125.*RK(N+RD)+546.*RK(2*N+RD)+54.*RK(3*N+RD)- 00000028 1378.*RK(4*N+RD))/625. 00000029 GOTO 20 00000030 126 RK(6*N+RD)=HD*DY(RD) 00000031 F0=0.1666666667*(RK(RD)+4.*RK(2*N+RD)+RK(3*N+RD)) 00000032 X=X0+HD 00000033 ER=(-42.*RK(RD)-224.*RK(2*N+RD)-21.*RK(3*N+RD)+162.*RK(4*N+RD) 00000034 1+125.*RK(6*N+RD))/67.2 00000035 YN=RK(5*N+RD)+F0 00000036 IF(ABS(YN).LT.1E-8) YN=1 00000037 ER=ABS(ER/YN) 00000038 IF(ER.GT.G0) GOTO 115 00000039 IF(ED.GT.ER) GOTO 20 00000040 QD=-1 00000041 20 Y(RD)=RK(5*N+RD)+F0 00000042 21 CONTINUE 00000043 22 CONTINUE </code></pre>
 

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