program spectra
	use kind_defs
	use FourierTransform
	implicit none
	integer, parameter :: N = 32768
	real(dbl) :: t(1:N), x(1:N), P(1:N), f, Ttot
	complex(dbl) :: c(1:N)
	integer :: i

	! Import data:
	print *, ' Importing data from "Data/simpel_short.dat".'
	open(50, file='Data/simpel_short.dat', status='old', action='read')
	do i = 1,N
		read(50, *) t(i), x(i)
	enddo
	close(50)

	print *, ' Making spectrum of data using the FFT for comparison'
	print *, ' with the Least Square-method.'

	! Make spectrum for comparison of FFT and Least Square:
	c = fft(x)
	P = abs(c)*2.0/sqrt(real(N))
	Ttot = maxval(t)-minval(t)
	open(51, file='Spectra.dat', status='replace', action='write')
	do i = 1,N/2
		f = (i-1)*(1e6/Ttot) ! The frequency in microHz
		write(51, *) f, P(i)
	enddo
	close(51)
	
	print *, ' Done. Spectrum saved in Spectra.dat.'
end program