"""
Ex 5.11 in A primer on...
"""


import numpy as np
import matplotlib.pyplot as plt
import sys

g = 9.81
n = 101

max_t = 0
max_y = 0

for v0 in sys.argv[1:]:
    v0 = float(v0)
    t_stop = 2*v0/g
    t = np.linspace(0,t_stop,n)
    y = v0*t - 0.5*g*t**2
    if max(t) > max_t:
        max_t = max(t)
    if max(y) > max_y:
        max_y = max(y)

    plt.plot(t,y)

plt.axis([0, max_t, 0, max_y*1.05])
plt.xlabel('time (s)')
plt.ylabel('height (m)')
plt.show()

"""
Terminal> python plot_ball2.py 2.4 3 4 1.1
output is a plot
"""