* rndsrc -- by CDHW -- writes a gausian random voltage source
*
* Note: see also the frontend command 'compose'
*
.control
begin
    setplot new
	set outfile = "PWL_File.inc"
	if ($argc = 2)
		let step = $argv[1]
		let duration =  $argv[2]
	else
		echo "usage  - rndsrc timestep duration"
		echo "effect - gaussian source written to file -- $outfile"
		unset outfile
		goto done
	endif
	
	set parity = true
	let time = 0
	echo "VpwlT OUT 0 PWL(" > $outfile
	
	while time < duration
		let time = time + step
		if $parity
		  let X1 = (1+rnd(32768))/32769
		  let X2 = rnd(32768)/32768*8*atan(1)
		  let Vnoise = sqrt(-2*ln(X1))*cos(X2)
		  set parity = false
		else
		  let Vnoise = sqrt(-2*ln(X1))*sin(X2)
		  set parity = true
		endif
		echo "+ $&time $&Vnoise" >> $outfile
	end
	echo "+ )" >> $outfile
	unset outfile parity
	label done
	destroy
end
.endc