set title "Spectrum of function cos(3t) using different sample times demonstrating leakage"
set xlabel "Frequecy"
set ylabel "Re(g(w))"
plot [x=2.3:4.3] [-9:9] "four11.txt" every :::11::11 using 1:2  title "Eight seconds"  with linespoints, \
"four11.txt" every :::13::13 using 1:2 title "Sixteen seconds" with linespoints, \
"four11.txt" every :::15::15 using 1:2 title "Thirty-two seconds" with linespoints, \
"four11.txt" every :::17::17 using 1:2 title "Sixty-four seconds" with linespoints, \
"four11.txt" every :::19::19 using 1:2 title "128 seconds" with linespoints