logistic.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Tue Nov 17 15:51:35 2020

@author: Nolte
"""

import numpy as np
from matplotlib import pyplot as plt

plt.close('all')
print('logistic.py')

# model_case 1 = logistic
# model_case 2 = cosine
# model_case 3 = cubed
model_case = int(input('Enter the Model Case (1-3)'))

if model_case == 1:
    ming = 2.9
    maxg = 4.0
    grep = 900
    ymin = 0
    ymax = 1
    xold = 0.231
    def logis(g,xin):
        xout = g*xin*(1.0-xin)
        return xout
elif model_case == 2:
    ming = 1
    maxg = 10
    grep = 900
    ymin = -1.2
    ymax = 1.2
    xold = 0.231
    def logis(g,xin):
        xout = np.cos(g*xin)
        return xout
else:
    ming = 1
    maxg = 3
    grep = 900
    xold = 0.231
    def logis(g,xin):
        xout = g*xin*(1-xin**2)
        return xout


rep = 64;

plt.figure(1)
plt.axes(xlim=(ming, maxg), ylim=(ymin, ymax))

for gainloop in range(grep):

    g=(maxg-ming)*gainloop/grep + ming;

    for sloop in range(100):			# settle-down loop
        xnew = logis(g,xold)        
        xold = xnew
    						    
    x = np.zeros(shape = (rep))
    y = np.zeros(shape = (rep))
    ind = 0
    for rloop in range(rep-1):
        xnew = logis(g,xold)  
        xold = xnew

        ind = ind + 1
        x[ind] = g + (maxg-ming)*(rloop-1)/(grep*rep);
        y[ind] = xnew;



    lines = plt.plot(x,y,'o',ms=1)
    plt.pause(0.05)
    plt.show()