Plotting a Parabolic Trajectory in Python: Step‑by‑Step Guide

Introduction

Based on a follower's request, this tutorial shows how to use Python to plot the solid line of a projectile's parabolic trajectory (horizontal launch with initial speed v).

1. Idea

The solution hinges on two points: calculating x and y coordinates from acceleration formulas, and then plotting these points. The physics formula for projectile motion is illustrated below.

2. Analysis

Previously we stored coordinates in a list; here we improve the approach by using a list comprehension to generate all points at once. The total height can be set arbitrarily, and horizontal and vertical positions are computed from the formulas before calling the plotting function.

3. Implementation

# coding: utf-8
import matplotlib.pyplot as plt
import numpy as np
import math

def pwx(v0, h):
    g = 9.8
    H = 5 * h
    t = math.sqrt(H/g)
    x = [v0 * t for t in np.arange(0, t, 0.1)]
    y = [H - 0.5 * g * t * t for t in np.arange(0, t, 0.1)]
    plt.title("Parabolic trajectory curve")
    plt.xlabel("x")
    plt.ylabel("y")
    plt.plot(x, y)  # plotting x and y
    plt.show()

if __name__ == "__main__":
    v = int(input("请输入初速度v:  "))
    h = int(input("请输入绘制行数h:  "))
    pwx(v, h)

Running the script in PyCharm and entering an initial speed of 5 and a plot height of 10 produces the following execution screenshot:

The Matplotlib library then displays a perfect parabolic curve:

Conclusion

This guide demonstrates one practical method to generate and plot the parabolic trajectory of a projectile using Python, fulfilling the follower's request and providing a foundation for further enhancements.