每个 X 具有多个 Y 值的 Python 散点图 [英] Python Scatter Plot with Multiple Y values for each X

问题描述

我正在尝试使用 Python 创建一个散点图，其中包含两个 X 类别cat1"cat2"，并且每个类别都有多个 Y 值.如果每个 X 值的 Y 值数量相同，我可以使用以下代码使其工作:

 将 numpy 导入为 np导入 matplotlib.pyplot 作为 plty = [(1,1,2,3),(1,1,2,4)]x = [1,2]py.plot(x,y)情节.show()

但是一旦每个 X 值的 Y 值数量不同，我就会收到错误消息.例如这不起作用:

 将 numpy 导入为 np导入 matplotlib.pyplot 作为 plty = [(1,1,2,3,9),(1,1,2,4)]x = [1,2]plt.plot(x,y)情节.show()#注意现在 x=1 有五个值，x=2 只有四个值.错误

如何为每个 X 值绘制不同数量的 Y 值，以及如何将 X 轴从数字 1 和 2 更改为文本类别cat1"和cat2".我将不胜感激！

这是我尝试制作的绘图类型的示例图像:

I am trying to use Python to create a scatter plot that contains two X categories "cat1" "cat2" and each category has multiple Y values. I can get this to work if the number of Y values for each X value is the same by using this following code:

    import numpy as np
    import matplotlib.pyplot as plt

    y = [(1,1,2,3),(1,1,2,4)]
    x = [1,2]
    py.plot(x,y)
    plot.show()

but as soon as the number of Y values for each X value is not the same, I get an error. For example this does not work:

    import numpy as np
    import matplotlib.pyplot as plt

    y = [(1,1,2,3,9),(1,1,2,4)] 
    x = [1,2]
    plt.plot(x,y)
    plot.show()
    #note now there are five values for x=1 and only four for x=2. error

How can I plot different numbers of Y values for each X value and how can I change the X axis from being the numbers 1 and 2 to text categories "cat1" and "cat2". I would greatly appreciate any help on this!

Here is a sample image of the type of plot I am trying to make:

http://s12.postimg.org/fa417oqt9/pic.png

解决方案

How can I plot different numbers of Y values for each X value

Just plot each group separately:

for xe, ye in zip(x, y):
    plt.scatter([xe] * len(ye), ye)

and how can I change the X axis from being the numbers 1 and 2 to text categories "cat1" and "cat2".

Set ticks and tick labels manually:

plt.xticks([1, 2])
plt.axes().set_xticklabels(['cat1', 'cat2'])

Full code:

import matplotlib.pyplot as plt
import numpy as np

y = [(1,1,2,3,9),(1,1,2,4)]
x = [1,2]

for xe, ye in zip(x, y):
    plt.scatter([xe] * len(ye), ye)

plt.xticks([1, 2])
plt.axes().set_xticklabels(['cat1', 'cat2'])

plt.savefig('t.png')

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