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TA貢獻(xiàn)1887條經(jīng)驗(yàn) 獲得超5個(gè)贊
我在你的代碼中做了一些更正。下面的代碼將繪制任何拋物線。您可以在繪圖中添加零點(diǎn)和極值點(diǎn)。
import matplotlib.pyplot as plt
import math
import numpy as np
a = int(input('Input a: '))
b = int(input('Input b: '))
c = int(input('Input c: '))
# calculate delta and zero points
delta = b**2 - 4*a*c
if delta > 0:
x_1 = (-b + math.sqrt(delta))/(2*a)
x_2 = (-b - math.sqrt(delta))/(2*a)
if delta == 0:
x_0 = -b/(2*a)
else:
pass
# calculate parabola extreme coordinates
p = -b/(2*a)
q = -delta/(4*a)
extreme = [p,q]
# define parabola function
def parabola(x,a,b,c):
y = a*x**2 + b*x + c
return y
# plot function
x = np.linspace(int(p)-5,int(p)+5,100)
y = parabola(x,a,b,c)
plt.plot(x,y)
plt.axhline(y=0, color='black', linestyle='-')
plt.axvline(x=0, color='black', linestyle='-')
plt.text(p-0.5, q-3, '[' + str(round(p,2)) +',' + str(round(q,2)) + ']',color='orange', fontsize=9)
plt.plot(p, q, marker="o")
if delta > 0:
plt.plot(x_1, 0, marker="o", color='green')
plt.text(x_1 - 0.5, 2, '[' + str(round(x_1,2)) + ']', color='green', fontsize=9)
plt.plot(x_2, 0, marker="o", color='green')
plt.text(x_2 - 0.5, 2, '[' + str(round(x_2,2)) + ']', color='green', fontsize=9)
if delta == 0:
plt.plot(x_0, 0, marker="o", color='green')
plt.text(x_0 - 0.5, 2, '[' + str(round(x_0,2)) + ']', color='green', fontsize=9)
plt.show()
樣本結(jié)果:
https://i.stack.imgur.com/bNprP.png
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