matplotlib学习

matplotlib学习
在docker中不能显示show，所以，需要save之后打开看
保存空白的
>>> import matplotlib as mpl
>>> mpl.use('Agg')
>>> import matplotlib.pyplot as plt
>>> plt.savefig('a.png')
>>> plt.savefig('a.jpg')


简单演示
import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(-1,1,50)
y = 2*x + 1
plt.plot(x,y) #plt相当于一个画板软件plot和savefig都是上面的按钮
plt.savefig('a.png')




一个图显示多个曲线
import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(-1,1,50)
y1 = 2*x + 1
y2 = 2**x + 1
plt.figure() #显示坐标轴
plt.plot(x,y1) 
plt.plot(x,y2)
plt.xlabel('I am x') #显示坐标轴名称
plt.ylabel('I am y')
plt.savefig('a.png')




显示多图
import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import numpy as np


plt.figure()
plt.subplot(2,2,1)
plt.plot([0,1],[0,1])


plt.subplot(222)
plt.plot([0,1],[0,2])


plt.subplot(223)
plt.plot([0,1],[0,3])


plt.subplot(224)
plt.plot([0,1],[0,4])
plt.savefig('a.png')


读取图像
import pdb
import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import numpy as np
import skimage.io
image = skimage.io.imread('girl.jpg')
plt.imshow(image) 
plt.savefig('a.png')
注意是imshow和savefig


ax
fig = ax.get_figure()
ax.imshow(masked_image.astype(np.uint8))
fig.savefig('masked.png')






[1] 参考资料 https://blog.csdn.net/Notzuonotdied/article/details/77876080