matplotlib基础画线

%matplotlib notebook提供一个交互的环境
1 %matplotlib notebook

import matplotlib as mpl
mpl.get_backend()

'nbAgg'

%plt.plot查询plot的帮助
1 import matplotlib.pyplot as plt
plt.plot?

#因为默认线的风格为'-'
#如果只进过一个点的话没有东西会被画出来
plt.plot(3, 2)

 

#使用'.'时可以显示
1 # we can pass in '.' to plt.plot to indicate that we want
# the point (3,2) to be indicated with a marker '.'
plt.plot(3, 2, '.')

# First let's set the backend without using mpl.use() from the scripting layer
from matplotlib.backends.backend_agg import FigureCanvasAgg
from matplotlib.figure import Figure

# create a new figure
fig = Figure()

# associate fig with the backend
canvas = FigureCanvasAgg(fig)

# add a subplot to the fig
ax = fig.add_subplot(111)

# plot the point (3,2)
ax.plot(3, 2, '.')

# save the figure to test.png
# you can see this figure in your Jupyter workspace afterwards by going to
# https://hub.coursera-notebooks.org/
canvas.print_png('test.png')

%%html
<img src='test.png' />

ax.axis设置坐标边界
 1 # create a new figure
plt.figure()

# plot the point (3,2) using the circle marker
plt.plot(3, 2, 'o')

# get the current axes
ax = plt.gca()

# Set axis properties [xmin, xmax, ymin, ymax]
ax.axis([0,6,0,10])

每次使用plt.plot画出来得颜色不同
1 # create a new figure
plt.figure()

# plot the point (1.5, 1.5) using the circle marker
plt.plot(1.5, 1.5, 'o')
# plot the point (2, 2) using the circle marker
plt.plot(2, 2, 'o')
# plot the point (2.5, 2.5) using the circle marker
plt.plot(2.5, 2.5, 'o')

1 # get current axes
ax = plt.gca()
# get all the child objects the axes contains
ax.get_children()