'lin_pol1.bas
'y=a0 + a1*x

x(1)=2.1:x(2)=6.22:x(3)=7.17:x(4)=10.52:x(5)=13.68
y(1)=2.9:y(2)=3.83:y(3)=5.98:y(4)= 5.71:y(5)= 7.74

a$(1)="a0 = "
a$(2)="a1 = "

    a=0:a1=0:a2=0:a3=0
    for i=1 to 5
    x=x(i):y=y(i)
     a=a+x
    a1=a1+x^2
    a2=a2+y
    a3=a3+x*y
    next i

    M=2
    C(1,1)=5
    C(2,1)=a
    C(1,2)=a
    C(2,2)=a1
    C(1,3)=a2
    C(2,3)=a3

   N=M+1
     FOR J=1 TO M
         MYI=J
  [LOOPMYI]
         I=MYI
         IF C(I,J)<>0 GOTO [CALC]
         MYI=MYI+1
         IF MYI<=M THEN [LOOPMYI]

        PRINT "SORRY, NO UNIQUE SOLUTION"
        END

  [CALC]
      FOR K=1 TO N
         X=C(J,K)
         C(J,K)=C(I,K)
         C(I,K)=X
      NEXT K
     Y=1/C(J,J)
     FOR K=1 TO N
       C(J,K)=Y*C(J,K)
     NEXT K

     FOR I=1 TO M
       IF I=J GOTO [LEAP]
       Y=C(I,J)*(-1)
         FOR K=1 TO N
           C(I,K)=C(I,K)+Y*C(J,K)
         NEXT K
      [LEAP]
     NEXT I
  NEXT J

     FOR J=1 TO M
   PRINT a$(J);C(J,N)'solution vector
   REM
 NEXT J
 END