set terminal postscript eps color enhanced font "Helvetica,16pt" size 8.6cm,6cm 

#set terminal pngcairo enhanced font "Helvetica,48pt" size 4000,3000

set output 'multiplot_fftspectra.eps'

set multiplot

# common settings
set format x "%2.0f"
#set format y "%2.0f"
set format y "10^{%T}"
set logscale y 10
set yr[1:2000]
set xr [440:580]
set xtics 20
set tics scale 1
set tics nomirror
set border linewidth 1

# bottom figure
set origin 0.02,0.0
set size 1.00,0.54
set ytics (1,10,100,1000)

set ylabel 'Intensity [a.u.]' offset -1.5
set xlabel 'Wavelength {/Symbol l} [nm]'
plot 'spectra.txt' using 2:($4*0.1) notitle w l lw 1 lc rgb 'red'

unset label
unset xtics
unset logscale y

# top figure
set origin 0.02,0.46
set size 1.00,0.54

set format y "%2.0f"
set format x2 "%2.1f"
set xr [0.00002:0.5] #GHz for data
set x2r [0.00002:0.5] #GHz for label
set yr[0.01:10.0] #microvolts
set ytics 5
#set ytics (0.0001,0.00001,0.000001)
set x2tics 0.1
set border linewidth 1
set x2label 'Timing Frequency [GHz]'
set xlabel ""
set ylabel 'Power [{/Symbol m}V]' offset -1.5

plot 'fft.txt' using ($1*0.000000001):($2*1000000) notitle w l lw 1 lc rgb 'red'

#plot 'fft.txt' using ($1*0.000000001):($2*1000000) notitle w points pt 1 ps 1 lc rgb 'red'


unset multiplot

reset