subroutine stat(N,sweepEnergy,ethalpy,sigma)
  use defs; implicit none
  integer(i4b),intent(in)::N
  real(dp),dimension(N),intent(in)::sweepEnergy
  real(dp),intent(out)::ethalpy,sigma
  integer(i4b)::i
  ethalpy = 0.
  do i = 1, N
     ethalpy = ethalpy + sweepEnergy(i)
  end do
  ethalpy = ethalpy/real(N,dp)
  sigma = 0.
  do i = 1, N
     sigma = sigma + (sweepEnergy(i) - ethalpy)**2
  end do
  sigma = sqrt(sigma/real(N*(N-1),dp))
end subroutine stat