使用 Matplotlib 的 Python 简单绘图
原文:https://www.geesforgeks.org/simple-plot-in-python-using-matplotlib/
Matplotlib 是一个 Python 库，它有助于可视化和分析数据，并借助于可以使用 Matplotlib 库进行模拟的图形化可视化来帮助更好地理解数据。Matplotlib 是一个用于静态、动画和交互式可视化的综合库。
matplotlib 库的安装
第一步:打开命令管理器(只需在窗口开始搜索栏中键入“cmd”) 第二步:在终端中键入以下命令。
cd Desktop
步骤 3: 然后键入以下命令。
pip install matplotlib
创建简单的绘图
蟒蛇 3
# importing the required module
import matplotlib.pyplot as plt
# x axis values
x = [1,2,3]
# corresponding y axis values
y = [2,4,1]
# plotting the points
plt.plot(x, y)
# naming the x axis
plt.xlabel('x - axis')
# naming the y axis
plt.ylabel('y - axis')
# giving a title to my graph
plt.title('My first graph!')
# function to show the plot
plt.show()
输出:
代码似乎不言自明。遵循了以下步骤:
-
将 x 轴和相应的 y 轴值定义为列表。
-
使用在画布上绘制它们。plot()函数。
-
使用给 x 轴和 y 轴命名。xlabel()和。ylabel()函数。
-
使用给你的情节一个标题。title()函数。
-
Finally, to view your plot, we use .show() function.
我们来看看 matplotlib 中经常用到的一些基本函数。
注意:试着一个一个去掉添加的特征，了解输出结果是如何变化的 例 1:
蟒蛇 3
import matplotlib.pyplot as plt
a = [1, 2, 3, 4, 5]
b = [0, 0.6, 0.2, 15, 10, 8, 16, 21]
plt.plot(a)
# o is for circles and r is
# for red
plt.plot(b, "or")
plt.plot(list(range(0, 22, 3)))
# naming the x-axis
plt.xlabel('Day ->')
# naming the y-axis
plt.ylabel('Temp ->')
c = [4, 2, 6, 8, 3, 20, 13, 15]
plt.plot(c, label = '4th Rep')
# get current axes command
ax = plt.gca()
# get command over the individual
# boundary line of the graph body
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
# set the range or the bounds of
# the left boundary line to fixed range
ax.spines['left'].set_bounds(-3, 40)
# set the interval by which
# the x-axis set the marks
plt.xticks(list(range(-3, 10)))
# set the intervals by which y-axis
# set the marks
plt.yticks(list(range(-3, 20, 3)))
# legend denotes that what color
# signifies what
ax.legend(['1st Rep', '2nd Rep', '3rd Rep', '4th Rep'])
# annotate command helps to write
# ON THE GRAPH any text xy denotes
# the position on the graph
plt.annotate('Temperature V / s Days', xy = (1.01, -2.15))
# gives a title to the Graph
plt.title('All Features Discussed')
plt.show()
输出:
例 2:
蟒蛇 3
import matplotlib.pyplot as plt
a = [1, 2, 3, 4, 5]
b = [0, 0.6, 0.2, 15, 10, 8, 16, 21]
c = [4, 2, 6, 8, 3, 20, 13, 15]
# use fig whenever u want the
# output in a new window also
# specify the window size you
# want ans to be displayed
fig = plt.figure(figsize =(10, 10))
# creating multiple plots in a
# single plot
sub1 = plt.subplot(2, 2, 1)
sub2 = plt.subplot(2, 2, 2)
sub3 = plt.subplot(2, 2, 3)
sub4 = plt.subplot(2, 2, 4)
sub1.plot(a, 'sb')
# sets how the display subplot
# x axis values advances by 1
# within the specified range
sub1.set_xticks(list(range(0, 10, 1)))
sub1.set_title('1st Rep')
sub2.plot(b, 'or')
# sets how the display subplot x axis
# values advances by 2 within the
# specified range
sub2.set_xticks(list(range(0, 10, 2)))
sub2.set_title('2nd Rep')
# can directly pass a list in the plot
# function instead adding the reference
sub3.plot(list(range(0, 22, 3)), 'vg')
sub3.set_xticks(list(range(0, 10, 1)))
sub3.set_title('3rd Rep')
sub4.plot(c, 'Dm')
# similarly we can set the ticks for
# the y-axis range(start(inclusive),
# end(exclusive), step)
sub4.set_yticks(list(range(0, 24, 2)))
sub4.set_title('4th Rep')
# without writing plt.show() no plot
# will be visible
plt.show()
输出:
