#/***********************************************************
#    bifur.rb -- カオスとアトラクタ
#***********************************************************/
require "window.rb"
XMAX = 640

printf("kmin = ");  kmin = gets.to_f
printf("kmax = ");  kmax = gets.to_f
printf("pmin = ");  pmin = gets.to_f
printf("pmax = ");  pmax = gets.to_f
puts "please wait ..."
gr_on();  gr_window(kmin, pmin, kmax, pmax, 0, 0)
gr_plot_start
dk = (kmax - kmin) / (XMAX - 1)
k = kmin; while (k <= kmax)
    p = 0.3
    for i in 1..50; p += k * p * (1 - p); end
    for i in 51..100
        if (p >= pmin && p <= pmax)
            gr_wdot(k, p)
        end
        p += k * p * (1 - p)
    end
    k += dk
end
gr_plot_end
gr_off

exit 0