Python科学计算-Matplotlib

Author：Xie Zhong-zhao Date： 2017/8/3 Running Environment: Python3.5

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1、Introduction to Matplotlib and basic line

import matplotlib.pyplot as plt fig = plt.figure(figsize = (10,6)) ax1 = fig.add_subplot(221) ax2 = fig.add_subplot(222) ax3 = fig.add_subplot(212) x = [1, 2, 3] y = [5, 7, 4] ax1.plot(x,x,'r') ax1.grid(True, color = 'g') ax2.plot(x,y,'b') ax2.grid(True, color = 'g') ax3.plot(x,y,'y') ax3.grid(True, color = 'g') plt.show()

2、Legends, Titles, and Labels with Matplotlib

import matplotlib.pyplot as plt x = [1,2,3] y = [5,7,4] x2 = [1,2,3] y2 = [10,14,12] fig = plt.figure(figsize = (8,5) ) plt.plot(x, y, label='First Line') plt.plot(x2, y2, label='Second Line') plt.xlabel('Plot Number') plt.ylabel('Important var') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.legend(loc = 'upper left') plt.show()

3、Bar Charts and Histograms with Matplotlib

import matplotlib.pyplot as plt fig = plt.figure(figsize = (10,6) ) plt.bar([1,3,5,7,9],[5,2,7,8,2], label="Example one") plt.bar([2,4,6,8,10],[8,6,2,5,6], label="Example two", color='g') plt.legend() plt.xlabel('bar number') plt.ylabel('bar height') plt.title('Epic Graph\nAnother Line! Whoa') plt.show()

import matplotlib.pyplot as plt population_ages = [22,55,62,45,21,22,34,42,42,4,99,102,110,120,121,122,130,111,115,112,80,75,65,54,44,43,42,48] bins = [0,10,20,30,40,50,60,70,80,90,100,110,120,130] plt.hist(population_ages, bins, histtype='bar', rwidth=0.8) plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.show() C:\Users\xxz\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py:531: UserWarning: No labelled objects found. Use label='...' kwarg on individual plots. warnings.warn("No labelled objects found. "

4、Scatter Plots with Matplotlib

import matplotlib.pyplot as plt import numpy as np plt.figure(figsize=(9, 6)) n = 1024 #rand and randn rand is uniform distribution randn means Gussian distribution X = np.random.randn(1, n) Y = np.random.randn(1, n) T = np.arctan2(Y, X) #alpha is transparent ability of dots #c reprensents color of dots plt.scatter(X, Y, s=50, c=T, alpha=.4, marker='o') plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.show() C:\Users\xxz\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py:531: UserWarning: No labelled objects found. Use label='...' kwarg on individual plots. warnings.warn("No labelled objects found. "

5、Stack Plots with Matplotlib

import matplotlib.pyplot as plt days = [1,2,3,4,5] sleeping = [7,8,6,11,7] eating = [2,3,4,3,2] working = [7,8,7,2,2] playing = [8,5,7,8,13] plt.stackplot(days, sleeping,eating,working,playing, colors=['m','c','r','k']) plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.show()

import matplotlib.pyplot as plt days = [1,2,3,4,5] sleeping = [7,8,6,11,7] eating = [2,3,4,3,2] working = [7,8,7,2,2] playing = [8,5,7,8,13] plt.plot([],[],color='m', label='Sleeping', linewidth=5) plt.plot([],[],color='c', label='Eating', linewidth=5) plt.plot([],[],color='r', label='Working', linewidth=5) plt.plot([],[],color='k', label='Playing', linewidth=5) plt.stackplot(days, sleeping,eating,working,playing, colors=['m','c','r','k']) plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.show()

6、Pie Charts with Matplotlib

import matplotlib.pyplot as plt slices = [7,2,2,13] activities = ['sleeping','eating','working','playing'] cols = ['c','m','r','b'] plt.pie(slices, labels=activities, colors=cols, startangle=90, shadow= True, explode=(0,0.1,0,0), autopct='%1.1f%%') plt.title('Interesting Graph\nCheck it out') plt.show()

7、Loading Data from Files for Matplotlib

import matplotlib.pyplot as plt import csv fig = plt.figure(figsize = (10,6)) x = [] y = [] with open('example.txt','r') as csvfile: plots = csv.reader(csvfile, delimiter=',') for row in plots: x.append(int(row[0])) print(x) y.append(int(row[1])) print(y) plt.plot(x,y, label='Loaded from file!') plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.show() import matplotlib.pyplot as plt import numpy as np fig = plt.figure(figsize = (10,6)) x, y = np.loadtxt('example.txt', delimiter=',', unpack=True) plt.plot(x,y, label='Loaded from file!') plt.xlabel('x') plt.ylabel('y') plt.title('Interesting Graph\nCheck it out') plt.legend() plt.show() [1] [5] [1, 2] [5, 2] [1, 2, 3] [5, 2, 4] [1, 2, 3, 4] [5, 2, 4, 8] [1, 2, 3, 4, 5] [5, 2, 4, 8, 3] [1, 2, 3, 4, 5, 6] [5, 2, 4, 8, 3, 6] [1, 2, 3, 4, 5, 6, 7] [5, 2, 4, 8, 3, 6, 8] [1, 2, 3, 4, 5, 6, 7, 8] [5, 2, 4, 8, 3, 6, 8, 3] [1, 2, 3, 4, 5, 6, 7, 8, 9] [5, 2, 4, 8, 3, 6, 8, 3, 2] [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] [5, 2, 4, 8, 3, 6, 8, 3, 2, 6]

8、3D graphs with Matplotlib

from mpl_toolkits.mplot3d import axes3d import matplotlib.pyplot as plt from matplotlib import style fig = plt.figure(figsize = (10,6)) style.use('fivethirtyeight') fig = plt.figure() ax1 = fig.add_subplot(111, projection='3d') x = [1,2,3,4,5,6,7,8,9,10] y = [5,6,7,8,2,5,6,3,7,2] z = [1,2,6,3,2,7,3,3,7,2] ax1.plot_wireframe(x,y,z) ax1.set_xlabel('x axis') ax1.set_ylabel('y axis') ax1.set_zlabel('z axis') plt.show() <matplotlib.figure.Figure at 0x1ca32b7d9e8>

9、3D Scatter Plot with Matplotlib

from mpl_toolkits.mplot3d import axes3d import matplotlib.pyplot as plt from matplotlib import style fig = plt.figure(figsize = (10,6)) style.use('ggplot') fig = plt.figure() ax1 = fig.add_subplot(111, projection='3d') x = [1,2,3,4,5,6,7,8,9,10] y = [5,6,7,8,2,5,6,3,7,2] z = [1,2,6,3,2,7,3,3,7,2] x2 = [-1,-2,-3,-4,-5,-6,-7,-8,-9,-10] y2 = [-5,-6,-7,-8,-2,-5,-6,-3,-7,-2] z2 = [1,2,6,3,2,7,3,3,7,2] ax1.scatter(x, y, z, c='g', marker='o') ax1.scatter(x2, y2, z2, c ='r', marker='o') ax1.set_xlabel('x axis') ax1.set_ylabel('y axis') ax1.set_zlabel('z axis') plt.show() <matplotlib.figure.Figure at 0x1ca30e80f60>

10、3D Bar Chart with Matplotlib

from mpl_toolkits.mplot3d import axes3d import matplotlib.pyplot as plt import numpy as np from matplotlib import style style.use('ggplot') fig = plt.figure(figsize = (10,6)) fig = plt.figure() ax1 = fig.add_subplot(111, projection='3d') x3 = [1,2,3,4,5,6,7,8,9,10] y3 = [5,6,7,8,2,5,6,3,7,2] z3 = np.zeros(10) dx = np.ones(10) dy = np.ones(10) dz = [1,2,3,4,5,6,7,8,9,10] ax1.bar3d(x3, y3, z3, dx, dy, dz) ax1.set_xlabel('x axis') ax1.set_ylabel('y axis') ax1.set_zlabel('z axis') plt.show() <matplotlib.figure.Figure at 0x1ca31048e48>

11、Conclusion with Matplotlib

from mpl_toolkits.mplot3d import axes3d import matplotlib.pyplot as plt import numpy as np from matplotlib import style #style.use('fivethirtyeight') style.use('bmh') fig = plt.figure() ax1 = fig.add_subplot(111, projection='3d') x, y, z = axes3d.get_test_data() print(axes3d.__file__) ax1.plot_wireframe(x,y,z, rstride = 5, cstride = 5) ax1.set_xlabel('x axis') ax1.set_ylabel('y axis') ax1.set_zlabel('z axis') plt.show() fig.savefig("conclusion.png", dpi=300) #save graph C:\Users\xxz\Anaconda3\lib\site-packages\mpl_toolkits\mplot3d\axes3d.py

12、 Text Annotation

import matplotlib.pyplot as plt import numpy as np fig = plt.figure(figsize = (10,6)) ax = fig.add_subplot(111) xx = np.arange(0,15,0.1) ax.plot(xx, xx**2, xx, xx**3) ax.text(13, 300, r"$y=x^2$", fontsize=20, color="blue"); ax.text(13, 3000, r"$y=x^3$", fontsize=20, color="green"); plt.show()

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