今回は今、人気急上昇中であるプログラミング言語の「Python」を使って、
ばねのプログラムを作成しました。
■ プログラム
from tkinter import *
from tkinter import messagebox
import numpy as np
import time, math
class Weight:
pos = np.array([0.0, 0.0]);
vel = np.array([0.0, 0.0]);
acc = np.array([0.0, 0.0]);
natural = np.array([0.0, 0.0]);
d = 0;
m = 0;
l = 0;
k = 0;
g = 0;
# コンストラクタの定義
def __init__(self, x, y):
self.pos = np.array([x, y]);
self.vel = np.array([0.0, 0.0]);
self.acc = np.array([0.0, 0.0]);
self.d = 40; # おもりの大きさ
self.m = 5; # おもりの重さ
self.l = 50; # ばねの自然長
self.k = 0.1; # ばね定数
self.g = 0.1; # 重力加速度
def display(self, canvas):
# おもりの描画
canvas.create_oval(self.pos[0]-10, self.pos[1]-10, self.pos[0]+10, self.pos[1]+10, fill="red", tag="DT")
def move(self, w):
# 計算
# 自然長での位置を計算
self.natural = self.pos - w.pos;
self.natural = self.natural / np.linalg.norm(self.natural);
self.natural = self.natural * self.l;
self.natural = self.natural + w.pos;
self.acc[0] = -1 * self.k * (self.pos[0] - self.natural[0]) / self.m; # 加速度 (x成分)
self.acc[1] = -1 * self.k * (self.pos[1] - self.natural[1]) / self.m; # 加速度 (y成分)
self.vel = self.vel + self.acc; # 速度
#self.vel = self.vel * 0.99; # 減衰
self.pos = self.pos + self.vel; # 位置
def decay(self):
self.vel *= 0.99; # 減衰
def gravity(self):
self.vel[1] += self.g; # 重力
def draw(canvas):
global n
canvas.delete("DT")
# ばねの描画
nn = n - 1
for num in range(nn):
canvas.create_line(weights[num].pos[0], weights[num].pos[1], weights[num+1].pos[0], weights[num+1].pos[1], fill="blue", tag="DT", width=1)
# おもりの描画
for num in range(n):
weights[num].display(canvas);
# 計算
weights[1].move(weights[0]);
weights[1].move(weights[2]);
weights[2].move(weights[1]);
weights[2].move(weights[3]);
weights[3].move(weights[2]);
weights[3].move(weights[4]);
weights[4].move(weights[3]);
weights[4].move(weights[5]);
weights[5].move(weights[4]);
weights[5].move(weights[6]);
weights[6].move(weights[5]);
weights[6].move(weights[7]);
weights[7].move(weights[6]);
weights[7].move(weights[8]);
weights[8].move(weights[7]);
weights[8].move(weights[9]);
weights[9].move(weights[8]);
# 減衰、重力
for num in range(n):
weights[num].decay();
weights[num].gravity();
#■メイン処理
n = 10;
weights = [] # 配列の宣言
# ■複数のインスタンスを生成する
weights.append(Weight(250, 2)) # インスタンスを生成し配列に格納する
weights.append(Weight(200, 100))
weights.append(Weight(300, 200))
weights.append(Weight(400, 300))
weights.append(Weight(500, 400))
weights.append(Weight(400, 500))
weights.append(Weight(300, 600))
weights.append(Weight(300, 700))
weights.append(Weight(300, 800))
weights.append(Weight(300, 900))
root=Tk(); root.title("ばねの運動")
canvas=Canvas(root,width=500, height=500)
canvas.pack()
while True:
while True:
draw(canvas);
root.update()
time.sleep(0.002)
if not messagebox.askokcancel("シミュレーション終了",
"再開しますか?"):break
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■ 参考サイト