subroutine CAtrace(nres,thecoord,CAatomnumber,theCA)
use defs; implicit none ! makes CA trace
integer(i4b), intent(in) :: nres
real(dp), dimension(:,:), intent(in) :: thecoord ! angstroms
integer(i4b), dimension(:), intent(in) :: CAatomnumber
real(dp), dimension(:,:), intent(out) :: theCA
integer(i4b) :: i

do i = 1, nres
  theCA(:,i) = thecoord(:,CAatomnumber(i))
end do
end subroutine CAtrace