1000 REM ***** MODIFIED TO RUN ON PDP-11-20 *****
1100 REM ***** PHIL ZUMSTEG ***** 4/20/72
9000 REM ***** LINFIT ***** MATHEMATICS PROGRAM *****
9001 REM ***** VERSION 1 ***** 7/31/69/ *****
9002 REM LINEAR CURVE FIT
9003 DIM P(21,21),Q(21,21),X(22),Y(21),B(21)
9004 READ N
9005 MAT X=CON(N+2)
9006 MAT Y=ZER(N+1)
9008 MAT Q=ZER(N+1,N+1)
9009 MAT B=ZER(N+1)
9010 MAT P=ZER(N+1,N+1)
9011 DEF FNR(Z)=INT(Z*1000+.5)/1000
9012 READ X(2)
9013 IF X(2)=-1.E+09 THEN 9025
9014 FOR I=3 TO N+2
9015 READ X(I)
9016 NEXT I
9017 FOR I=1 TO N+1
9018 FOR J=1 TO N+1
9019 LET P(I,J)=P(I,J)+X(I)*X(J)
9020 NEXT J
9021 LET Y(I)=Y(I)+X(I)*X(N+2)
9022 NEXT I
9023 LET S5=S5+X(N+2)*X(N+2)
9024 GOTO 9012
9025 LET M=P(1,1)
9026 LET S2=Y(1)
9027 FOR I=2 TO N+1
9028 PRINT "FACTOR";I-1,"CORRELATION =";
9029 LET S1=P(1,I)
9030 LET S3=Y(I)
9031 LET S4=P(I,I)
9032 LET A=M*S3-S1*S2
9033 LET B=(M*S4-S1^2)*(M*S5-S2^2)
9034 PRINT FNR(A/SQR(B))
9035 NEXT I
9036 PRINT
9037 MAT Q=INV(P)
9038 MAT B=Q*Y
9039 PRINT "COEFFICIENTS OF BEST LINEAR LIT:"
9040 PRINT
9041 FOR I=2 TO N+1
9042 PRINT FNR(B(I));
9043 NEXT I
9044 PRINT
9045 PRINT
9046 PRINT "CONSTANT TERM ="FNR(B(1))
9900 DATA 2
9901 DATA 1,3,6,2,1,6,.5,1.5,3.5,1.3,1.6,5.2,2.4,3,8.8,2,3.5,8.5
9902 DATA -1.E+09
9999 END