#!/usr/bin/gnuplot

#set terminal postscript enhanced
#set output "neumann.ps"
set terminal postscript eps enhanced 26
set output "neumann.eps"

set line style 1 linetype 7 linewidth 1
set line style 2 linetype 1 linewidth 3

# ciary do bodu P
set arrow 1 from -5, graph 0 to -5,-2000 nohead linestyle 1
set arrow 2 from -20,-2000   to -5,-2000 nohead linestyle 1
# vodorovna ciara v bode y = M
set arrow 3 from -20,6500    to 20,6500  nohead linestyle 1
# sipky na osiach x, y
set arrow 4 from graph 0, graph 0 to graph 0, graph 1 head lw 2
set arrow 5 from graph 0, graph 0 to graph 1, graph 0 head lw 2

set label "P" at -4.5,-2000
set label "y = f_{/Symbol x}(x)" at 6,1000
set label "y" at -22,10000

set xtics ("a" -20, "b" 20, "w_1" -5)
set ytics ("M" 6500, "0" -25000, "w_2" -2000)

set nox2tics

set xlabel "x"
#set ylabel "y"

#f(x) = -0.12*x**4 + 40*x**2 - 100*x +5 
f(x) = - 0.25*x**4 + 2*x**3 + 50*x**2 - 600*x 

plot [-20:20] [-25000:10000] f(x) notitle linestyle 2

#pause -1