如何显示 matplotlib 图？

Question

I am sure the configuration of matplotlib for python is correct since I have used it to plot some figures.

But today it just stop working for some reason. I tested it with really simple code like:

import matplotlib.pyplot as plt
import numpy as np
x = np.arange(0, 5, 0.1)
y = np.sin(x)
plt.plot(x, y)

There's no error but just no figure shown up.

I am using python 2.6, Eclipse in Ubuntu

Answer 1

In matplotlib you have two main options:

1. Create your plots and draw them at the end:

    import matplotlib.pyplot as plt plt.plot(x, y) plt.plot(z, t) plt.show() 

2. Create your plots and draw them as soon as they are created:

    import matplotlib.pyplot as plt from matplotlib import interactive interactive(True) plt.plot(x, y) raw_input('press return to continue') plt.plot(z, t) raw_input('press return to end') 

Answer 2

您必须在末尾使用plt.show()才能看到图

Answer 3

In case anyone else ends up here using Jupyter Notebooks, you just need

%matplotlib inline

Purpose of "%matplotlib inline"

Answer 4

将图表保存为png

plt.savefig("temp.png")

Answer 5

You have to use show() methode when you done all initialisations in your code in order to see the complet version of plot:

import matplotlib.pyplot as plt

plt.plot(x, y)
................
................
plot.show()

Answer 6

plt.plot(X,y) function just draws the plot on the canvas. In order to view the plot, you have to specify plt.show() after plt.plot(X,y) . So,

import matplotlib.pyplot as plt
X = //your x
y = //your y
plt.plot(X,y)
plt.show()

Answer 7

import numpy as np

import matplotlib.pyplot as plt

x1 = 5 * np.random.rand(50)

x2 = 5 * np.random.rand(50) + 25

x3 = 30 * np.random.rand(25)

x = np.concatenate((x1, x2, x3))

y1 = 5 * np.random.rand(50)

y2 = 5 * np.random.rand(50) + 25

y3 = 30 * np.random.rand(25)

y = np.concatenate((y1, y2, y3))

color_array = ['b'] * 50 + ['g'] * 50 + ['r'] * 25

plt.scatter(x, y, s=[50], marker='D', c=color_array)

plt.show()