我怎样才能从我的情节中删除多余的线？

Question

I want to plot some data:

u1 = []

for i in range(12):
    u1.append(10)

f = [14.04, 13.31, 12.71, 11.89, 9.92, 8.53, 14.04, 14.92, 15.42, 16.14, 17.42, 20.78]

u2 = [5.8, 4.8, 3.8, 2.8, 1.8, 0.8, 5.8, 4.8, 3.8, 2.8, 1.8, 0.8]

Ku = [round(i/j, 2)*100 for i, j in zip(u2, u1)]

plt.plot(f, Ku)
plt.show()

When I use scatter plot everything seems to work fine:

However when I use plot function it adds an extra line that connects first point and a maximum point. But I need only one curve that connects these points .

Answer 1

You have to sort the x and y values.

x,y = zip(*[(a,b) for a,b in sorted(zip(f,Ku))])
plt.plot(x,y)
plt.show()

Answer 2

If you look at the f list, which you use as your x axis, you'll see that the values are not ordered. Matplotlib just follows the line in the order of the points you give it.

You can do the following before the plotting to sort the values in the correct order:

import numpy as np
ord = np.flip(np.argsort(f))
f_orderd = np.array(f)[ord]
Ku_ordered =np.array(Ku)[ord]
plt.plot(f_ordered,Ku_ordered); 
plt.show()