Fortran to Matlab, B-Spline,
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
program bspline_fit
use toolbox
implicit none
integer :: ord,typ,ni,no
real :: t,dt
real, allocatable :: nvo(:),nvi(:),crd0(:,:),crd1(:,:)
integer :: i,j
! input data (the number of control points will be equal to the number of data points)
write (*,*) "Enter the number of data points"
read (*,*) ni
write (*,*) "Enter the order of the curve"
read (*,*) ord
no = ni+ord
write (*,*) "Enter the type of the knot vector"
write (*,*) "(1) periodic uniform (2) open uniform (3) nonuniform"
read (*,*) typ
allocate (crd0(ni,2),crd1(ni,2),nvi(ni),nvo(no))
call data_read(ni,crd0) ! input data
call data_vec(ni,crd0,nvi) ! parametric coordinates of the data points
call knot_vec(typ,ord,ni,no,nvo) ! knot vector
call control_vec(ord,ni,no,nvi,nvo,crd0,crd1) ! parametric coordinates of the control points
call curve(ord,ni,no,nvi,nvo,crd1) ! resulting curve
end program bspline_fit
--------------------------------------
module toolbox
contains
subroutine data_read(n,crd)
implicit none
integer,intent(in) :: n
real,intent(out) :: crd(n,2)
integer :: i,j,k
open (1,file = 'in.dat')
do i=1,n ; read (1,*) k,(crd(i,j),j=1,2) ; end do
end subroutine data_read
subroutine data_vec(n,crd,nvi)
implicit none
integer,intent(in) :: n
real,intent(in) :: crd(n,2)
real,intent(out) :: nvi(n)
real :: dif(2),clen(n-1)
integer :: i
do i=1,n-1
dif = crd(i+1,:)-crd(i,:)
clen(i) = sqrt(dif(1)**2+dif(2)**2)
end do
nvi(1) = 0
do i=2,n
nvi(i) = nvi(i-1)+clen(i-1)
end do
nvi = nvi/sum(clen)
write (*,'(20(f5.2,2x))') (nvi(i),i=1,n) ; write (*,*)
end subroutine data_vec
subroutine knot_vec(typ,ord,ni,no,nvo)
integer,intent(in) :: typ,ord,ni,no
real,intent(out) :: nvo(no)
integer :: i
select case(typ)
case(1)
case(2)
do i=1,no
if (i <= ord) then
nvo(i) = 0
else if (i >= ni+1) then
nvo(i) = ni+1-ord
else
nvo(i) = i-ord
end if
end do
case(3)
end select
nvo = nvo/nvo(no)
write (*,'(20(f5.2,2x))') (nvo(i),i=1,no)
end subroutine knot_vec
subroutine control_vec(ord,ni,no,nvi,nvo,crd0,crd1)
integer,intent(in) :: ord,ni,no
real,intent(in) :: nvi(ni),nvo(no),crd0(ni,2)
real,intent(out) :: crd1(ni,2)
real :: cmat(ni,ni)
integer :: i
open (3,file='tmp.dat')
do i=1,ni
call basis_fnc(ord,ni,no,nvo,nvi(i),cmat(i,:))
end do
do i=1,ni ; write (*,'(20(f6.3,2x))') (cmat(i,j),j=1,ni) ; end do ; write (3,*)
call mat_inv(ni,cmat) ; crd1 = matmul(cmat,crd0)
do i=1,ni ; write (3,'(i3,1x,3(f6.3,2x))') i,crd1(i,1),crd1(i,2) ; end do ; write (3,*)
end subroutine control_vec
subroutine basis_fnc(ord,ni,no,x,t,cv)
implicit none
integer,intent(in) :: ord,ni,no
real,intent(in) :: x(no),t
real,intent(out) :: cv(ni)
real :: bf(ord,no-1),r
integer :: i,j,k
bf = 0
k = no-1
do i=1,ord
if (i == 1) then
do j=1,k
if (t >= x(j) .and. t <= x(j+1)) then
bf(i,j) = 1
else
bf(i,j) = 0
end if
end do
else
k = k-1
do j=1,k
r = x(i+j-1)-x(j) ; if (r /= 0) bf(i,j) = (t-x(j))*bf(i-1,j)/r
r = x(i+j)-x(j+1) ; if (r /= 0) bf(i,j) = bf(i,j)+(x(i+j)-t)*bf(i-1,j+1)/r
end do
end if
write (3,'(20(f6.3,2x))') (bf(i,j),j=1,k)
end do
cv = bf(ord,1:ni)
end subroutine basis_fnc
subroutine curve(ord,ni,no,nvi,nvo,crd1)
implicit none
integer,intent(in) :: ord,ni,no
real,intent(in) :: nvi(ni),nvo(no),crd1(ni,2)
real :: cv(ni),crd(2),t
integer :: i,j,k
real,parameter :: dt = 1./20
open (2,file = 'out.dat')
t = 0 ; i = 1
do
call basis_fnc(ord,ni,no,nvo,t,cv)
do j=1,2 ; crd(j) = dot_product(cv,crd1(:,j)) ; end do
write (2,'(i3,2x,2(f5.2,2x))') i,(crd(j),j=1,2)
i = i+1 ; t = t+dt ; if (t > nvi(ni)) exit
end do
end subroutine curve
! matrix inverse
subroutine mat_inv(n,a)
implicit none
integer,intent(in) :: n
real,intent(inout) :: a(n,n)
integer :: i
real :: v1(n),v2(n)
call sgetrf(n,n,a,n,v1,i) ! lapack lu decomposition
call sgetri(n,a,n,v1,v2,n,i) ! lapack matrix inverse
end subroutine mat_inv
end module toolbox
---------------------------------------
Is there anyone can help me to transform this code to Matlab?
0 Kommentare
Antworten (0)
Siehe auch
Kategorien
Mehr zu Interpolation finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!