线段集合

使用Matplotlib绘制线条。

LineCollection 允许在图上绘制多条线。 下面我们展示它的一些属性。

  1. import matplotlib.pyplot as plt
  2. from matplotlib.collections import LineCollection
  3. from matplotlib import colors as mcolors
  5. import numpy as np
  7. # In order to efficiently plot many lines in a single set of axes,
  8. # Matplotlib has the ability to add the lines all at once. Here is a
  9. # simple example showing how it is done.
  11. x = np.arange(100)
  12. # Here are many sets of y to plot vs x
  13. ys = x[:50, np.newaxis] + x[np.newaxis, :]
  15. segs = np.zeros((50, 100, 2))
  16. segs[:, :, 1] = ys
  17. segs[:, :, 0] = x
  19. # Mask some values to test masked array support:
  20. segs = np.ma.masked_where((segs > 50) & (segs < 60), segs)
  22. # We need to set the plot limits.
  23. fig, ax = plt.subplots()
  24. ax.set_xlim(x.min(), x.max())
  25. ax.set_ylim(ys.min(), ys.max())
  27. # colors is sequence of rgba tuples
  28. # linestyle is a string or dash tuple. Legal string values are
  29. #          solid|dashed|dashdot|dotted.  The dash tuple is (offset, onoffseq)
  30. #          where onoffseq is an even length tuple of on and off ink in points.
  31. #          If linestyle is omitted, 'solid' is used
  32. # See :class:`matplotlib.collections.LineCollection` for more information
  33. colors = [mcolors.to_rgba(c)
  34.           for c in plt.rcParams['axes.prop_cycle'].by_key()['color']]
  36. line_segments = LineCollection(segs, linewidths=(0.5, 1, 1.5, 2),
  37.                                colors=colors, linestyle='solid')
  38. ax.add_collection(line_segments)
  39. ax.set_title('Line collection with masked arrays')
  40. plt.show()

线段集合示例

为了在一组轴中有效地绘制多条线，Matplotlib能够一次性添加所有线。 这是一个简单的例子，展示了它是如何完成的。

  1. N = 50
  2. x = np.arange(N)
  3. # Here are many sets of y to plot vs x
  4. ys = [x + i for i in x]
  6. # We need to set the plot limits, they will not autoscale
  7. fig, ax = plt.subplots()
  8. ax.set_xlim(np.min(x), np.max(x))
  9. ax.set_ylim(np.min(ys), np.max(ys))
  11. # colors is sequence of rgba tuples
  12. # linestyle is a string or dash tuple. Legal string values are
  13. #          solid|dashed|dashdot|dotted.  The dash tuple is (offset, onoffseq)
  14. #          where onoffseq is an even length tuple of on and off ink in points.
  15. #          If linestyle is omitted, 'solid' is used
  16. # See :class:`matplotlib.collections.LineCollection` for more information
  18. # Make a sequence of x,y pairs
  19. line_segments = LineCollection([np.column_stack([x, y]) for y in ys],
  20.                                linewidths=(0.5, 1, 1.5, 2),
  21.                                linestyles='solid')
  22. line_segments.set_array(x)
  23. ax.add_collection(line_segments)
  24. axcb = fig.colorbar(line_segments)
  25. axcb.set_label('Line Number')
  26. ax.set_title('Line Collection with mapped colors')
  27. plt.sci(line_segments)  # This allows interactive changing of the colormap.
  28. plt.show()

线段集合示例2

参考

此示例中显示了以下函数，方法，类和模块的使用：

  1. import matplotlib
  2. matplotlib.collections
  3. matplotlib.collections.LineCollection
  4. matplotlib.cm.ScalarMappable.set_array
  5. matplotlib.axes.Axes.add_collection
  6. matplotlib.figure.Figure.colorbar
  7. matplotlib.pyplot.colorbar
  8. matplotlib.pyplot.sci

下载这个示例