python - Matplotlib:将不同的线组合成一个可以多次绘制的对象

Question

在matplotlib中，我如何组合一系列 X-Y 值(例如，每个值都在一个数组或列表中)，以便稍后多次绘制在一起(与其他元素一起，这是一个绘制不同事物的一般模式)？

我想计算/提取它们一次，然后将它们合并到一个对象/形状中，以便在一个命令中正确绘制，而不必总是单独绘制它们:

import matplotlib.pyplot as plt
import numpy

# Simple example
numpy.random.seed(4)
x = range(10)
y = numpy.random.rand(10)

# Create three 'lines' (here, as x-y arrays) with different lenghts
a = numpy.array((x, y*10)).T
b = numpy.array((x[:5]*y[:5], y[:5]**2)).T
c = numpy.array((x[3:7], x[3:7])).T

# Combine a, b, and c in one object to be called many times later
# (this is not a good way to do that)
abc = numpy.concatenate((a, b, c))

# Plot
fig = plt.figure(figsize=(9,3))

ax0 = fig.add_subplot(131)
ax0.plot(a[:,0], a[:,1], color='b')
ax0.plot(b[:,0], b[:,1], color='r')
ax0.plot(c[:,0], c[:,1], color='g')
ax0.set_title("3 lines to be combined")

ax1 = fig.add_subplot(132)
ax1.plot(a[:,0], a[:,1], color='b')
ax1.plot(b[:,0], b[:,1], color='b')
ax1.plot(c[:,0], c[:,1], color='b')
ax1.set_title("Desired output")

ax2 = fig.add_subplot(133)
ax2.plot(abc[:,0], abc[:,1], color='b') # 1-line command
ax2.set_title("Wrong (spaghetti plot)")

编辑

汤姆的答案很好地解决了我的问题，建立在我上面的尝试之上(即在单个数组中连接)。任何其他具有不同方法的解决方案仍然欢迎学习新东西(例如，是否可以构建单个 matplotlib 对象(Artist 左右)？)。

Answer 1

如果您想要的是用一行的方式绘制 a、b 和 c，您可以这样做:

ax2.plot(a[:,0], a[:,1], b[:,0], b[:,1], c[:,0], c[:,1], color='b')

编辑:

要使用原始对象之间仍具有换行符的单个对象，您可以使用 numpy.NaN 来换行。

import matplotlib.pyplot as plt
import numpy

# Simple example
numpy.random.seed(4)
x = range(10)
y = numpy.random.rand(10)

# Create three 'lines' (here, as x-y arrays) with different lenghts
a = numpy.array((x, y*10)).T
b = numpy.array((x[:5]*y[:5], y[:5]**2)).T
c = numpy.array((x[3:7], x[3:7])).T

# Use this to break up the original objects. 
# plt.plot does not like NaN's, so will break the line there.
linebreak=[[numpy.NaN,numpy.NaN]]

# Combine a, b, and c in one object to be called many times later
abc = numpy.concatenate((a, linebreak, b, linebreak, c))

# Plot
fig = plt.figure(figsize=(9,3))

ax0 = fig.add_subplot(131)
ax0.plot(a[:,0], a[:,1], color='b')
ax0.plot(b[:,0], b[:,1], color='r')
ax0.plot(c[:,0], c[:,1], color='g')
ax0.set_title("3 lines to be combined")

ax1 = fig.add_subplot(132)
ax1.plot(a[:,0], a[:,1], color='b')
ax1.plot(b[:,0], b[:,1], color='b')
ax1.plot(c[:,0], c[:,1], color='b')
ax1.set_title("Desired output")

ax2 = fig.add_subplot(133)
ax2.plot(abc[:,0], abc[:,1], color='b') # 1-line command
ax2.set_title("Single object with breaks")