C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Adds the given input(s) till a zero input is found.
        WRITE(*,*)'                      Give your input(s) now : '
        SUM = 0.0
  1     READ(*,*)X
        IF (X.EQ.0.0) THEN
        GO TO 1000
        ELSE
        SUM = SUM + X
        WRITE(*,*)'NEXT ? '
        GO TO 1
        ENDIF
 1000   WRITE(*,*)'------------------------------------------------ '
        WRITE(*,*)'Your result is :                   ', SUM   
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds the two unknowns for a pair of linear  Co-Equations.
  1     WRITE(*,*)'Give your inputs now : A1, B1, C1, A2, B2, C2 '
        READ(*,*)A1, B1, C1, A2, B2, C2
        DENOM = A1*B2 - A2*B1
        IF (DENOM.EQ.0.0) THEN
        WRITE(*,*)'Inputs are not valid'
        GO TO 1001
        ELSE
        X = (B1*C2 - B2*C1)/DENOM
        Y = (C1*A2 - C2*A1)/DENOM
        WRITE(*,*)'Your results are :'
        WRITE(*,*)'x =',X,'              y = ',Y
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Solves a system of simultaneous linear equations by the Gaussian
C       Elimination Method
C       C
        DIMENSION COEFF(20,20),TEMPOR(21,21),EQUALS(20),RESULT(20)
        REAL MINUTE
        MINUTE = 1.0E-32
        WRITE(*,*)'Enter the number of unknowns ( maximum 20 ) :'
        READ(*,*)N
        CHECKN = ABS(FLOAT(N) - 11.0)
        IF (CHECKN.GT.9.0) THEN
          WRITE(*,*)'    I am in no mood of a joke ! '
          GO TO 1001
        ENDIF
C       C
C       Reading the equations :
        WRITE(*,*) 'Reading the equations :'
        DO 1 I = 1,N,1
        WRITE(*,*) ' '
        WRITE(*,*)'Reading Equation No.',I
        DO 2 J = 1,N,1
        WRITE(*,*)'Enter the coefficient of the',J,'th variable now :'
        READ(*,*) COEFF(I,J)
        TEMPOR(I,J) = COEFF(I,J) 
    2   CONTINUE
        WRITE(*,*)'Enter the R.H.S. of the',I,'th equation now :'
        READ(*,*) EQUALS(I)
        TEMPOR(I,N+1) = EQUALS(I) 
    1   CONTINUE
C       C
C       Forming the upper triangular matrix :
        WRITE(*,*) 'Forming the upper triangular matrix : '
        WRITE(*,*) ' '
        K = 1
    3   DO 4 L = K+1,N,1
        IF (ABS(TEMPOR(L,K)).GT.ABS(TEMPOR(K,K))) THEN
        DO 5 M = 1,N+1,1
        TEMPOR(21,M) = TEMPOR(K,M)
        TEMPOR(K,M)  = TEMPOR(L,M)
        TEMPOR(L,M)  = TEMPOR(21,M)
    5   CONTINUE
        ENDIF
    4   CONTINUE
        IF (ABS(TEMPOR(K,K)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        DO 6 I = K+1,N,1
        FACTOR = (-1.0)*TEMPOR(I,K)/TEMPOR(K,K)
        DO 7 J = 1,N+1,1
        TEMPOR(I,J) =  TEMPOR(I,J) + FACTOR * TEMPOR(K,J) 
    7   CONTINUE
    6   CONTINUE
        K = K + 1
        IF (K.LT.N) GO TO 3
        IF (ABS(TEMPOR(N,N)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        WRITE(*,*) 'Formed.'
        WRITE(*,*)' '
C       C
C       Solving the upper triangular system of equations :
        WRITE(*,*)'Solving the upper triangular system of equations :'
        WRITE(*,*) ' '
        RESULT(N) = TEMPOR(N,N+1)/TEMPOR(N,N)
        DO 8 I = N-1,1,-1
        REMAIN = 0.0
        DO 9 J = I+1,N,1
        REMAIN = REMAIN + RESULT(J)*TEMPOR(I,J)
    9   CONTINUE
        RESULT(I) = (TEMPOR(I,N+1) - REMAIN)/TEMPOR(I,I)
    8   CONTINUE
        DO 10 I = 1,N,1
        WRITE(*,*)'The',I,'th variable is : ', RESULT(I)
   10   CONTINUE
        WRITE(*,*) ' '
        WRITE(*,*)'Enter any number ( say, 0 ) to continue :'
        READ(*,*) EXACT
C       C
C       Verifying the results now :
        WRITE(*,*) 'Verifying the results now : '
        WRITE(*,*) ' '
        EXACT = 1.0
        DO 11 I = 1,N,1
        ALHS = 0.0
        DO 12 J = 1,N,1
        ALHS = ALHS + COEFF(I,J) * RESULT(J)
   12   CONTINUE
        WRITE(*,*) 'Equation No.',I,'gives : ',ALHS,'=',EQUALS(I)
        IF (ALHS.NE.EQUALS(I)) THEN
        EXACT = 0.0
        ENDIF
   11   CONTINUE
        WRITE(*,*) ' '
        IF (EXACT.EQ.0.0) THEN
        WRITE(*,*) 'So the results are not exact.'
        ENDIF
        IF (EXACT.EQ.1.0) THEN
        WRITE(*,*) 'So the results are exact.'
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds the  EMI for a loan from the Housing Dev. Fin. Corp., India
  1     WRITE(*,*)'Give your inputs now : AMLOAN, PCRATE, YEARS'
        READ(*,*) AMLOAN, PCRATE, YEARS
        FACTOR = 1.0 + PCRATE/100.0
        FINAMT = AMLOAN * ( FACTOR ** YEARS)
        EYI = FINAMT * ( FACTOR - 1.0)/ ( FACTOR ** YEARS - 1.0 )
        IEMI = IFIX (EYI/12.0 + 1.0)
 999    WRITE(*,*)'Your result is :'
 1000   WRITE(*,*)'EMI =  Rs.',IEMI
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C       Calculates integral of a function by trapezoidal rule.
C2345   To change the integrand, change statements 1 & 3
        WRITE(*,*)'Give the lower and upper limit of x :'
        READ(*,*) DN, UP
        WRITE(*,*)'Give the number of divisions :'
        READ(*,*) DIV
        N = IFIX(DIV)
        ICOUNT = 0
        RANGE = UP - DN
        DIFF = RANGE/DIV
  1     SUM = 0.5 * DIFF * ( SIN(DN) + SIN(UP) )
  2     ICOUNT = ICOUNT + 1
        IF(ICOUNT.GE.N) THEN
        GO TO 1000
        ELSE
        X = DN + RANGE * (FLOAT(ICOUNT))/DIV
  3     SUM = SUM + SIN(X) * DIFF
        GO TO 2
        ENDIF
 1000   WRITE(*,*)'The integral is :', SUM
        STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C       Calculates integral of a function by trapezoidal rule.
C2345   To change the integrand, change statements 1 & 3
        WRITE(*,*)'Give the initial and final limit of x :'
        READ(*,*) STARTX, ENDX
        WRITE(*,*)'Give the No. of great divisions and of fine ones:'
        READ(*,*) GDIV, DIV
        NGREAT = IFIX(GDIV)
        N = IFIX(DIV)
        TOTSUM = 0.0
        IGREAT = 0
        GRANGE = ENDX - STARTX
 100    DN = STARTX + GRANGE * FLOAT(IGREAT)/GDIV
        UP = DN + GRANGE/GDIV
        ICOUNT = 0
        RANGE = UP - DN
        DIFF = RANGE/DIV
  1     SUM = 0.5 * DIFF * ( EXP(-DN) + EXP(-UP) )
  2     ICOUNT = ICOUNT + 1
        IF(ICOUNT.GE.N) THEN
        GO TO 1000
        ELSE
        X = DN + RANGE * (FLOAT(ICOUNT))/DIV
  3     SUM = SUM + EXP(-X) * DIFF
        GO TO 2
        ENDIF
 1000   TOTSUM = TOTSUM + SUM
        IGREAT = IGREAT + 1
        WRITE(*,*)'The current value of integral is :', TOTSUM
        WRITE (*,*)'at the upper limit :', UP
        WRITE(*,*)'.'
        IF(IGREAT.GE.NGREAT) THEN
        WRITE(*,*)'The complete integral is :', TOTSUM
        ELSE
        GO TO 100
        ENDIF
        STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   To solve some other equation iteratively, change statement 1
        WRITE(*,*)'Give your input now, i.e., X (it must not be zero)'
        READ(*,*)X
        ICOUNT = 1
  1     Y = COS(X)
        RELERR = (Y-X)/X
        REABS = ABS(RELERR)
        IF (REABS.LT.0.000002) THEN
        X = (X + Y)/2.0
        WRITE(*,*)'The solution is X =',X,'(At',ICOUNT,'th operation)'
        GO TO 1001
        ELSE
        ICOUNT = ICOUNT + 1
        ENDIF
        IF (ICOUNT.GT.1000) THEN
        WRITE(*,*)'   One thousand operations have been performed.'
        WRITE(*,*)'   Not yet converging to a solution.'
        GO TO 1001
        ELSE
        X = Y
        GO TO 1
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Performs linear least-square fitting.
        SUMX = 0.0
        SUMY = 0.0
        SUMXY = 0.0
        SUMXSQ = 0.0
        SUMYSQ = 0.0
        WRITE(*,*)'How many points are there ? '
        READ(*,*)EN
        EN2 = EN - 2.0
        WAEN2 = ANINT(ABS(EN2))
        IF (WAEN2.NE.EN2) THEN
        GO TO 1000
        ELSE
        N = IFIX(EN)
        ICOUNT = 0
        ENDIF
        WRITE(*,*)'         O.K., Give the pairs (x,y) now '
  1     ICOUNT = ICOUNT + 1
        IF (ICOUNT.GT.N) THEN
        GO TO 999
        ELSE
        WRITE(*,*)' Give a pair now : '
        READ(*,*) X, Y
        SUMX = SUMX + X
        SUMY = SUMY + Y
        SUMXY = SUMXY + X*Y
        SUMXSQ = SUMXSQ + X*X
        SUMYSQ = SUMYSQ + Y*Y
        GO TO 1
        ENDIF
  999   DIFF = EN*SUMXY - SUMX*SUMY 
        DIFFX = EN*SUMXSQ - SUMX*SUMX 
        DIFFY = EN*SUMYSQ - SUMY*SUMY
        IF(DIFFX.EQ.0.0) GO TO 1000
        IF(DIFFY.EQ.0.0) GO TO 1000
        WRITE(*,*)'The number of data is :', N
        AVEX = SUMX/EN
        AVEY = SUMY/EN
        WRITE(*,*)'The averages are :', AVEX , AVEY
        DEVX = SQRT(DIFFX)/EN
        DEVY = SQRT(DIFFY)/EN
        WRITE(*,*)'The standard deviations are :', DEVX , DEVY
        CORREL = DIFF/SQRT(DIFFX*DIFFY)
        EM = DIFF/DIFFX
        C = (SUMY*SUMXSQ - SUMX*SUMXY)/DIFFX
        WRITE(*,*)'The coefficient of correlation is :', CORREL
        WRITE(*,*)'The least-square fitting is given by : '
        WRITE(*,*)'m =  ', EM, '                   c = ',C
        GO TO 1001
 1000   WRITE(*,*)'    I am in no mood of a joke ! '
 1001   STOP
        END



C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Performs a polynomial fitting for a curve given by points
C       C
        DIMENSION POINTS(20,2),COEFF(20,20),TEMPOR(21,21),RESULT(20)
        REAL MINUTE
        MINUTE = 1.0E-32
        WRITE(*,*)'Enter the number of points ( maximum 20 ) :'
        READ(*,*)N
        CHECKN = ABS(FLOAT(N) - 11.0)
        IF (CHECKN.GT.9.0) THEN
          WRITE(*,*)'    I am in no mood of a joke ! '
          GO TO 1001
        ENDIF
C       C
C       Reading the points :
        WRITE(*,*) 'Reading the points :'
        DO 101 I = 1,N,1
        WRITE(*,*) ' '
        WRITE(*,*)'Enter the 2 Coordinates of Point No.',I
        READ(*,*) POINTS(I,1),POINTS(I,2)
        TEMPOR(I,N+1) = POINTS(I,2)
  101   CONTINUE
C       C
C       Forming the coefficient matrix :
        WRITE(*,*) 'Forming the coefficient matrix : '
        WRITE(*,*) ' '
        DO 102 I = 1,N,1
        COEFF(I,1)  = 1.0
        TEMPOR(I,1) = 1.0
        DO 103 J = 2,N,1
        COEFF(I,J) = POINTS(I,1) ** (J-1)
        TEMPOR(I,J) = COEFF(I,J)
  103   CONTINUE
  102   CONTINUE
        WRITE(*,*) 'Formed.'
        WRITE(*,*)' '
C       C
C       Forming the upper triangular matrix :
        WRITE(*,*) 'Forming the upper triangular matrix : '
        WRITE(*,*) ' '
        K = 1
    3   DO 4 L = K+1,N,1
        IF (ABS(TEMPOR(L,K)).GT.ABS(TEMPOR(K,K))) THEN
        DO 5 M = 1,N+1,1
        TEMPOR(21,M) = TEMPOR(K,M)
        TEMPOR(K,M)  = TEMPOR(L,M)
        TEMPOR(L,M)  = TEMPOR(21,M)
    5   CONTINUE
        ENDIF
    4   CONTINUE
        IF (ABS(TEMPOR(K,K)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        DO 6 I = K+1,N,1
        FACTOR = (-1.0)*TEMPOR(I,K)/TEMPOR(K,K)
        DO 7 J = 1,N+1,1
        TEMPOR(I,J) =  TEMPOR(I,J) + FACTOR * TEMPOR(K,J) 
    7   CONTINUE
    6   CONTINUE
        K = K + 1
        IF (K.LT.N) GO TO 3
        IF (ABS(TEMPOR(N,N)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        WRITE(*,*) 'Formed.'
        WRITE(*,*)' '
C       C
C       Solving the upper triangular system of equations :
        WRITE(*,*)'Solving the upper triangular system of equations :'
        WRITE(*,*) ' '
        RESULT(N) = TEMPOR(N,N+1)/TEMPOR(N,N)
        DO 8 I = N-1,1,-1
        REMAIN = 0.0
        DO 9 J = I+1,N,1
        REMAIN = REMAIN + RESULT(J)*TEMPOR(I,J)
    9   CONTINUE
        RESULT(I) = (TEMPOR(I,N+1) - REMAIN)/TEMPOR(I,I)
    8   CONTINUE
        DO 10 I = 1,N,1
        WRITE(*,*)'The',I,'th variable is : ', RESULT(I)
   10   CONTINUE
        WRITE(*,*) ' '
C       C
C       Verifying the results now :
        WRITE(*,*) 'Verifying the results now : '
        WRITE(*,*) ' '
        EXACT = 1.0
        DO 11 I = 1,N,1
        ALHS = 0.0
        DO 12 J = 1,N,1
        ALHS = ALHS + COEFF(I,J) * RESULT(J)
   12   CONTINUE
        WRITE(*,*) 'Equation No.',I,'gives : ',ALHS,'=',POINTS(I,2)
        IF (ALHS.NE.POINTS(I,2)) THEN
        EXACT = 0.0
        ENDIF
   11   CONTINUE
        WRITE(*,*) ' '
        IF (EXACT.EQ.0.0) THEN
        WRITE(*,*) '( So the results are not exact. )'
        ENDIF
        IF (EXACT.EQ.1.0) THEN
        WRITE(*,*) '( So the results are exact. )'
        ENDIF
        WRITE(*,*) ' '
        WRITE(*,*) 'Hence the polynomial suggested is :'
        WRITE(*,*) ' '
        WRITE(*,*) RESULT(1)
        DO 104 K = 2,N,1
        WRITE(*,*) 'PLUS',RESULT(K),'  INTO X TO THE POWER',K-1
  104   CONTINUE
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds whether a given natural number is prime or not.
        WRITE(*,*)'Give your input now i.e., the number : '
        READ(*,*)A
        A2 = A - 2.0
        AA2 = ABS(A2)
        WAA2 = ANINT (AA2)
        IF (WAA2.NE.A2) THEN
        WRITE(*,*)'Cannot you give a proper input ?'
        GO TO 1001
        ELSE
        DIVSOR = 2.0
        ENDIF
  1     RATIO = A/DIVSOR
        IF(DIVSOR.GT.RATIO) THEN
        WRITE(*,*)'              Prime'
        GO TO 1001
        ELSE
        QUOTNT = ANINT(RATIO)
        ENDIF
        IF (QUOTNT.EQ.RATIO) THEN
        WRITE(*,*)'          Not prime'
        GO TO 1001
        ELSE
        DIVSOR = DIVSOR + 1.0
        GO TO 1
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Performs quadratic least-square fitting.
        DIMENSION COEFF(3,3),EQUALS(3),TEMPOR(4,4),RESULT(3)
        REAL MINUTE
        MINUTE = 1.0E-32
        SUMX   = 0.0
        SUMX2  = 0.0
        SUMX3  = 0.0
        SUMX4  = 0.0
        SUMY   = 0.0
        SUMXY  = 0.0
        SUMX2Y = 0.0
        WRITE(*,*)'How many points are there ? '
        READ(*,*)EN
        EN3 = EN - 3.0
        WAEN3 = ANINT(ABS(EN3))
        IF (WAEN3.NE.EN3) THEN
         WRITE(*,*)'    I am in no mood of a joke ! '
         GO TO 1001
        ELSE
         N = IFIX(EN)
         ICOUNT = 0
        ENDIF
        WRITE(*,*)'     Enter the Coordinates of the Points now :'
        WRITE(*,*) ' '
  1     ICOUNT = ICOUNT + 1
        IF (ICOUNT.GT.N) THEN
        GO TO 999
        ELSE
        WRITE(*,*)'     Enter the Coordinates of the Point No.',ICOUNT
        READ(*,*) X, Y
        SUMX  = SUMX  + X
        SUMX2 = SUMX2 + X*X
        SUMX3 = SUMX3 + X*X*X
        SUMX4 = SUMX4 + X*X*X*X
        SUMY  = SUMY  + Y
        SUMXY = SUMXY + X*Y
        SUMX2Y= SUMX2Y+ X*X*Y
        GO TO 1
        ENDIF
C       C
C       Forming the coefficient matrix :
  999   WRITE(*,*) 'Forming the coefficient matrix :'
        WRITE(*,*) ' '
        N = 3
        COEFF(1,1)  = EN
        COEFF(1,2)  = SUMX
        COEFF(1,3)  = SUMX2
        COEFF(2,1)  = SUMX
        COEFF(2,2)  = SUMX2
        COEFF(2,3)  = SUMX3
        COEFF(3,1)  = SUMX2
        COEFF(3,2)  = SUMX3
        COEFF(3,3)  = SUMX4
        EQUALS(1)   = SUMY
        EQUALS(2)   = SUMXY
        EQUALS(3)   = SUMX2Y
        DO 101 I = 1,3,1
        DO 102 J = 1,3,1
        TEMPOR(I,J) = COEFF(I,J) 
 102    CONTINUE
        TEMPOR(I,4) = EQUALS(I)
 101    CONTINUE
        WRITE(*,*) 'Formed.'
        WRITE(*,*)' '
C       C
C       Forming the upper triangular matrix :
        WRITE(*,*) 'Forming the upper triangular matrix : '
        WRITE(*,*) ' '
        K = 1
    3   DO 4 L = K+1,N,1
        IF (ABS(TEMPOR(L,K)).GT.ABS(TEMPOR(K,K))) THEN
        DO 5 M = 1,N+1,1
        TEMPOR(4,M) = TEMPOR(K,M)
        TEMPOR(K,M)  = TEMPOR(L,M)
        TEMPOR(L,M)  = TEMPOR(4,M)
    5   CONTINUE
        ENDIF
    4   CONTINUE
        IF (ABS(TEMPOR(K,K)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        DO 6 I = K+1,N,1
        FACTOR = (-1.0)*TEMPOR(I,K)/TEMPOR(K,K)
        DO 7 J = 1,N+1,1
        TEMPOR(I,J) =  TEMPOR(I,J) + FACTOR * TEMPOR(K,J) 
    7   CONTINUE
    6   CONTINUE
        K = K + 1
        IF (K.LT.N) GO TO 3
        IF (ABS(TEMPOR(N,N)).LT.MINUTE) THEN
        WRITE(*,*)' '
        WRITE(*,*)'Sorry, unable to solve this system of equations !'
        GO TO 1001
        ENDIF
        WRITE(*,*) 'Formed.'
        WRITE(*,*)' '
C       C
C       Solving the upper triangular system of equations :
        WRITE(*,*)'Solving the upper triangular system of equations :'
        WRITE(*,*) ' '
        RESULT(N) = TEMPOR(N,N+1)/TEMPOR(N,N)
        DO 8 I = N-1,1,-1
        REMAIN = 0.0
        DO 9 J = I+1,N,1
        REMAIN = REMAIN + RESULT(J)*TEMPOR(I,J)
    9   CONTINUE
        RESULT(I) = (TEMPOR(I,N+1) - REMAIN)/TEMPOR(I,I)
    8   CONTINUE
        DO 10 I = 1,N,1
        WRITE(*,*)'The',I,'th variable is : ', RESULT(I)
   10   CONTINUE
        WRITE(*,*) ' '
C       C
C       Verifying the results now :
        WRITE(*,*) 'Verifying the results now : '
        WRITE(*,*) ' '
        EXACT = 1.0
        DO 11 I = 1,N,1
        ALHS = 0.0
        DO 12 J = 1,N,1
        ALHS = ALHS + COEFF(I,J) * RESULT(J)
   12   CONTINUE
        WRITE(*,*) 'Equation No.',I,'gives : ',ALHS,'=',EQUALS(I)
        IF (ALHS.NE.EQUALS(I)) THEN
        ENDIF
   11   CONTINUE
        WRITE(*,*) ' '
        WRITE(*,*) 'Hence the quadratic polynomial suggested is :'
        WRITE(*,*) ' '
        WRITE(*,*) 'Y equals '
        WRITE(*,*) ' '
        WRITE(*,*) '    ',RESULT(1)
        WRITE(*,*) 'PLUS',RESULT(2),'  INTO X TO THE POWER  1 '
        WRITE(*,*) 'PLUS',RESULT(3),'  INTO X TO THE POWER  2 '
        WRITE(*,*) ' '
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds the real roots, if any, of a quadratic equation.
  1     WRITE(*,*)'Give your inputs now : a, b,c '
        READ(*,*)A,B,C
        IF (A.EQ.0.0) THEN
          WRITE(*,*) 'Equation not quadratic'
          GO TO 1001
        ELSE
          B2 = B * B
          AC4 = 4.0 * A * C
        ENDIF
        IF ( B2.LT.AC4 ) THEN
          WRITE(*,*) 'Roots are complex'
          GO TO 1001
        ELSE
          SR = SQRT(B2 - AC4)
          ROOT1 = ( -B + SR )/(2.0 * A)
          ROOT2 = ( -B - SR )/(2.0 * A)
 999      WRITE(*,*)'Your results are :'
 1000     WRITE(*,*)ROOT1,ROOT2
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds the final amount of an STDR at the State Bank of India.
  1     WRITE(*,*)'Give your inputs now : DEPOSIT, PCRATE, YEARS'
        READ(*,*) DEPSIT, PCRATE, YEARS
        FACTOR = 1.0 + PCRATE/400.0
        QUARTS = 4.0 * YEARS
        FINAMT = DEPSIT * (FACTOR ** QUARTS)
        FINAMT = ANINT(FINAMT)
        INTFIN = IFIX(FINAMT)
 999    WRITE(*,*)'Your result is :'
 1000   WRITE(*,*)'The final amount is Rs.', INTFIN
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Sums a given series : to change the series change statement 2
        EN = 1.0
        TERM = 1.0
        SUM = 1.0
  1     IF (EN.GT.10000.0) THEN
        WRITE(*,*)'Ten thousand operations were performed ;'
        WRITE(*,*)'Not yet converging to a solution.'
        WRITE(*,*) SUMOLD , SUM
        GO TO 1001
        ELSE
        SUMOLD = SUM
        EN = EN + 1.0
  2     TERM = TERM/(EN - 1.0)
        SUM = SUM + TERM
        ENDIF
        IF (SUM.EQ.SUMOLD) THEN
 1000   WRITE(*,*)'The series converges to :', SUM
        GO TO 1001
        ELSE
        GO TO 1
        ENDIF
 1001   STOP
        END




C       T1  RULER  2  RULER  3  RULER  4  RULER  5  RULER  6  RULER  7
C2345   Finds some statistical parameters for a simple set of data.
        ICOUNT = 0
        SUMX = 0.0
        SUMXSQ = 0.0
        WRITE(*,*)'     How many data are there ? '
        READ(*,*)EN
        IF (EN.LT.2.0) THEN
        GO TO 1001
        ELSE
        N = IFIX(EN)
        ENDIF
  1     ICOUNT = ICOUNT + 1
        IF (ICOUNT.GT.N) THEN
        GO TO 1000
        ELSE
        WRITE(*,*)'     Data Please ! '
        READ(*,*) X
        SUMX = SUMX + X
        SUMXSQ = SUMXSQ + X*X
        GO TO 1
        ENDIF
 1000   AVE = SUMX/FLOAT(N)
        VAR = SUMXSQ/FLOAT(N) - AVE * AVE
        SD = SQRT(VAR)
        WRITE(*,*)'Number of data is',N
        WRITE(*,*)'Average is',AVE,'     Population std. dev.is',SD
        WRITE(*,*)'Sum is',SUMX,'          Sum of squares is',SUMXSQ
 1001   STOP
        END