#Exer. 5.11 from "A primer on..."
import numpy as np
import matplotlib.pyplot as plt
import sys

"""
We are asked to seet the lengths of the coordinate axes, and to do
this we need to find the maximum values of t and y. We use
a simple and general method to do this. For this particular case
it could be done much smarter, but the approach shown here is
very general and useful to know about.
"""

v0_list = sys.argv[1:]
g = 9.81

max_t = 0
max_y = 0

for v0 in v0_list:
    v0 = float(v0)
    t_stop = 2*v0/g

    t = np.linspace(0,t_stop,101)
    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.title('Ball plot 2')
plt.xlabel('time (s)')
plt.ylabel('height (m)')
plt.axis([0, max_t, 0, max_y*1.05])


plt.show()

"""
Terminal> python plot_ball3.py 3 5 9
output is a plot
"""