PROGRAM nag_lin_reg_ex01

      ! Example Program Text for nag_lin_reg
      ! NAG fl90, Release 4. NAG Copyright 2000.

      ! .. Use Statements ..
      USE nag_examples_io, ONLY : nag_std_out, nag_std_in
      USE nag_lin_reg, ONLY : nag_simple_lin_reg
      ! .. Implicit None Statement ..
      IMPLICIT NONE
      ! .. Intrinsic Functions ..
      INTRINSIC KIND
      ! .. Parameters ..
      INTEGER, PARAMETER :: wp = KIND(1.0D0)
      REAL (wp), PARAMETER :: x_miss = 0.0_wp
      REAL (wp), PARAMETER :: y_miss = 99.0_wp
      ! .. Local Scalars ..
      INTEGER :: i, n
      ! .. Local Arrays ..
      REAL (wp) :: result(21)
      REAL (wp), ALLOCATABLE :: x(:), y(:)
      ! .. Executable Statements ..
      WRITE (nag_std_out,*) 'Example Program Results for nag_lin_reg_ex01'

      READ (nag_std_in,*)          ! Skip heading in data file
      READ (nag_std_in,*) n

      ALLOCATE (x(n),y(n))         ! Allocate storage

      DO i = 1, n
        READ (nag_std_in,*) x(i), y(i)
      END DO

      CALL nag_simple_lin_reg(x,y,result,x_miss=x_miss,y_miss=y_miss)

      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) &
       '              ***** Descriptive Statistics *****           '
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) 'Variable             Mean        Std-deviation'
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,'(1x,a,5x,f8.4,7x,f10.4)') 'response (Y) ', &
       result(2), result(4), 'predictor (X)', result(1), result(3)
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) &
       '             ***** Analysis of variance (ANOVA) table *****       '
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) 'Source of variation      D.F      &
       &Sum of squares      Mean square     F-value'
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,'(1x,a,15x,f3.0,6x,f14.4,6x,f11.4,4x,f8.4)') &
       'Regression', result(13), result(12), result(14:15), 'Error     ', &
       result(17), result(16), result(18)
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,'(1x,a,15x,f3.0,6x,f14.4)') 'Total     ', result(20), &
       result(19)
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,'(a,f7.4)') ' Coeff. of determination (R^2)= ', &
       result(5)**2
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) &
       '            ***** Estimates of regression parameters *****      '
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,*) &
       '              Estimate          std-error         t-value  '
      WRITE (nag_std_out,*)
      WRITE (nag_std_out,'(1x,a,5x,f8.4,9x,f9.4,9x,f7.4)') 'intercept', &
       result(7), result(9), result(11), 'slope    ', result(6), result(8), &
       result(10)

      DEALLOCATE (x,y)             ! Deallocate storage

    END PROGRAM nag_lin_reg_ex01