# -*- coding: utf-8 -*-
"""
Created on Tue Oct 15 13:47:44 2019

@author: nvanderkroon
"""

import matplotlib.pyplot as plt
import numpy as np

f = 1.5 #N
m = 2 #kg
a_haas = f/m
v_0 = 1.3 #ms^-1
a_schildpad = -0.1 #ms^-2
s_0 = 15 #m

t = np.linspace(0, 10, 1000)

def shaas(a, t):
    return 0.5*a*t**2

def sschildpad(s0, v0, a, t):
    return s0+(v0+a*0.5*t)*t

def verschil(sh, ss):
    return sh - ss

s_haas = shaas(a_haas, t)
s_schildpad = sschildpad(s_0, v_0, a_schildpad, t)
vschl = verschil(s_haas, s_schildpad)

#index = np.argwhere(np.diff(np.sign(s_haas - s_schildpad)))

def getindex(haas, schildpad):
    for i in range(len(haas)):
        if haas[i] >= schildpad[i]:
            return i



index = getindex(s_haas, s_schildpad)

plt.plot(t, s_haas) #plot van haas
plt.plot(t, s_schildpad)

plt.plot(t[index], s_schildpad[index], 'rx')

tijd = np.round(float(t[index]), 3)

print('De haas kruist de schildpad op t = ', tijd, 'seconden en haalt hem hierna dus in')