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| from Tkinter import *
MAXTIME = 50
INIT_GROWTHRATE = 0.3
MAXY = 500
CARRYING_CAPACITY = 200
# --------------------------------------------
# GRAPHICS STUFF
win = Tk()
can = Canvas(win, width = 600, height = 400, background = "white")
yax = can.create_line(20,20,20,380, width=2,fill='black')
xax = can.create_line(20,380,580,380, width=2,fill='black')
for i in range(0,MAXY,100):
can.create_text(20,380-((float(i)/MAXY)*380),text=str(i))
for i in range(0,MAXTIME,50):
can.create_text(20+(float(i)/float(MAXTIME))*580, 390,text=str(i))
can.pack()
def graph_it(prev,t, v):
x = ((float(t) / float(MAXTIME)) * 580) + 20
y = 380 - ((float(v) / MAXY)*380 + 20)
can.create_rectangle(x-1,y-1,x+2,y+2,width=0,fill='blue')
can.create_line(prev[0],prev[1],x,y,width=1,fill='blue')
can.pack()
return [x,y]
# GRAPHICS STUFF
# --------------------------------------------
def growthrate(p):
return (-INIT_GROWTHRATE/CARRYING_CAPACITY)*popsize + INIT_GROWTHRATE
popsize = 5.0
prev = [20,380 - ((popsize / MAXY)*380 + 20)]
for t in range(0,MAXTIME):
popsize += popsize * growthrate(popsize)
prev = graph_it(prev,t, popsize)
win.mainloop() |
