# --------------------------------------
# CSCI 127: Joy and Beauty of Data
# MatPlotLib Introductory Example
# --------------------------------------

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

# --------------------------------------

def plot_line(x1, y1, x2, y2):
    """Plot a line using the specified points."""
    x = [x1, x2]
    y = [y1, y2]
    plt.plot(x, y)

# --------------------------------------

def plot_sine_wave(start_x, stop_x, amplitude):
    """Plot a sine wave."""
    x_array = np.linspace(start_x, stop_x, 1000)
    y_list = []
    for x in x_array:
        y_list.append(amplitude * math.sin(x))
    plt.plot(x_array, y_list)

# --------------------------------------

def main(graph_min, graph_max):
    
    plt.xlim(graph_min, graph_max)
    plt.ylim(graph_min, graph_max)

    plot_line(graph_min, graph_min, graph_max, graph_max)
    plot_line(graph_min, graph_max, graph_max, graph_min)
    plot_sine_wave(graph_min // 2, graph_max // 2, graph_max // 4)

    plt.show()

# --------------------------------------

main(-100, 100)