define N (8*4096)
	set x=1,$N
	erase
	window 1 1 1 1

	limits 0 1024 -5 5
	box
	ptype 1 1
	# generate a lot of points to uniformly cover -0.5 to 0.5
	# -and- at the same time do averages of 10 samples => pseudo-gaussian
	set y=x*0
	do i=1,10 {
		set t=random($N)-0.5
		set y=y+t
	}

	# prepare and plot the pseudo gaussian points
	set y[0]=0
	set y[$($N-1)]=0
	set y=y/1.5
	set s=0.01*cos(6.2832*x/128)
	set s= 50-(x%128)==0? 0.5:0
	set s= abs(50-(x%128))==1? 0.4:s
	set s= abs(50-(x%128))==2? 0.3:s
	set s= abs(50-(x%128))==3? 0.2:s
	set s= abs(50-(x%128))==4? 0.1:s
	set y=y+s

#	print data.6 {y }

# FIRST PLOT:  a bit of the data
#
        connect x y
	cursor

# SECOND PLOT:  the whole power spectrum
        set yi=0*y
	set ynew=y*-1.0**int(x)
	fft 1 ynew yi re im
	set a=(re*re+im*im)
	limits x a
	erase
	box
	connect x a
	stats  a ave  sig kur
        	echo ...
	echo stats a ave sig kur
	echo ave=$ave    sigma=$sig
	echo ...
	echo vecminmax a mn mx
	vecminmax a mn mx
	echo min=$mn   max=$mx
	echo
	cursor
# THIRD PLOT:  the positive, low frequency power spectrum.
	erase
	set x=x-(1+$N/2)
	limits 0 2048 a
	box
	connect x a