绘图的线型、颜色、标记

绘图：.plot()

plt.plot()：绘制点和线^[1]

from numpy.random import randn
plt.plot(randn(50).cumsum(),'k--')   # 生成50个正态分布的数

• randn函数返回一个或一组样本，具有标准正态分布；
• cumsum函数计算各行的累加值^[2]；
• in：

import numpy as np
a = np.array([1,2,3,4,5,6])
a.cumsum()

• out：

array([ 1, 3, 6, 10, 15, 21])

k-- 是线性选项，指定黑色虚线；

颜色（color），标记(marker)，线型(linestyle)

指定绿色虚线：

ax.plot(x,y,'g--')  # 一样的效果，更简洁
ax.plot(x,y,linestyle='--',color='g')

指定黑色虚线，标记类型：

plt.plot(randn(50).cumsum(),'ko--')
plt.plot(randn(50).cumsum(),color='k',linestyle='dashed',marker='o')

用字符串指定时，颜色一定在最前面，可规范顺序：color+marker+line style

Color^[3]：

Long Name	Short Name	RGB Triplet
blue	b	[0,0,1]
black	k	[0,0,0]
red	r	[1,0,0]
green	g	[0,1,0]
yellow	y	[1,1,0]
cyan	c	[0,1,1]
magenta	m	[1,0,1]
white	w	[1,1,1]

Marker^[4]：

Marker	Description	Resulting Marker
"o"	Circle
"+"	Plus sign
"*"	Asterisk
"."	Point
"x"	Cross
"_"	Horizontal line
" | "	Vertical line
"square"	Square
"diamond"	Diamond
"^"	Upward-pointing triangle
"v"	Downward-pointing triangle
">"	Right-pointing triangle
"<"	Left-pointing triangle
"pentagram"	Pentagram
"hexagram"	Hexagram

Line Style^[4]：

Line Style	Description	Resulting Line
"-"	Solid line
"- -"	Dashed line
":"	Dotted line
"-."	Dash-dotted line

Draw Style：在线型图中，可按非线性插值；

plt.plot(randn(50),'ko--',drawstyle='steps-post',label='steps-post')  
plt.legend(loc="best")  # 给图像加图例

image

目前有三种可选：steps、steps-mid、steps-post 具体差别还待探究；

image
该图出处：https://matplotlib.org/stable/gallery/lines_bars_and_markers/step_demo.html

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1. https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html#matplotlib.pyplot.plot ↩

2. https://blog.csdn.net/banana1006034246/article/details/78841461 ↩

3. http://math.loyola.edu/~loberbro/matlab/html/colorsInMatlab.html ↩

4. https://www.mathworks.com/help/matlab/creating_plots/specify-line-and-marker-appearance-in-plots.html ↩ ↩