! D02JAF Example Program Text
! Mark 26.1 Release. NAG Copyright 2016.
Module d02jafe_mod
! D02JAF Example Program Module:
! Parameters and User-defined Routines
! .. Use Statements ..
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: bc, cf
! .. Parameters ..
Integer, Parameter, Public :: nin = 5, nout = 6
Contains
Function cf(j,x)
! .. Function Return Value ..
Real (Kind=nag_wp) :: cf
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: x
Integer, Intent (In) :: j
! .. Executable Statements ..
If (j==2) Then
cf = 0.0E0_nag_wp
Else
cf = 1.0E0_nag_wp
End If
Return
End Function cf
Subroutine bc(i,j,rhs)
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (Out) :: rhs
Integer, Intent (In) :: i
Integer, Intent (Out) :: j
! .. Executable Statements ..
rhs = 0.0E0_nag_wp
If (i==1) Then
j = 1
Else
j = -1
End If
Return
End Subroutine bc
End Module d02jafe_mod
Program d02jafe
! D02JAF Example Main Program
! .. Use Statements ..
Use d02jafe_mod, Only: bc, cf, nin, nout
Use nag_library, Only: d02jaf, e02akf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Real (Kind=nag_wp) :: dx, x, x0, x1, y
Integer :: i, ia1, ifail, k1, k1max, kp, kpmax, &
lw, m, n
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: c(:), w(:)
Integer, Allocatable :: iw(:)
! .. Intrinsic Procedures ..
Intrinsic :: real
! .. Executable Statements ..
Write (nout,*) 'D02JAF Example Program Results'
! Skip heading in data file
Read (nin,*)
! n: order of the differential equation
! k1: number of coefficients to be returned
! kp: number of collocation points
Read (nin,*) n, k1max, kpmax
lw = 2*(kpmax+n)*(k1max+1) + 7*k1max
Allocate (iw(k1max),c(k1max),w(lw))
! x0: left-hand boundary, x1: right-hand boundary.
Read (nin,*) x0, x1
Write (nout,*)
Write (nout,*) ' KP K1 Chebyshev coefficients'
Do kp = 10, kpmax, 5
Do k1 = 4, k1max, 2
! ifail: behaviour on error exit
! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call d02jaf(n,cf,bc,x0,x1,k1,kp,c,w,lw,iw,ifail)
Write (nout,99999) kp, k1, c(1:k1)
End Do
End Do
k1 = 8
m = 9
ia1 = 1
Write (nout,*)
Write (nout,99998) 'Last computed solution evaluated at', m, &
' equally spaced points'
Write (nout,*)
Write (nout,*) ' X Y'
dx = (x1-x0)/real(m-1,kind=nag_wp)
x = x0
Do i = 1, m
ifail = 0
Call e02akf(k1,x0,x1,c,ia1,k1max,x,y,ifail)
Write (nout,99997) x, y
x = x + dx
End Do
99999 Format (1X,2(I3,1X),8F8.4)
99998 Format (1X,A,I5,A)
99997 Format (1X,2F10.4)
End Program d02jafe