演示Curvelinear网格

自定义网格和记号行。

此示例演示如何通过在网格上应用转换，使用GridHelperCurve线性来定义自定义网格和注释行。这可以用作第二个打印上的演示，用于在矩形框中创建极轴投影。

Curvelinear网格示例

  1. import numpy as np
  3. import matplotlib.pyplot as plt
  4. import matplotlib.cbook as cbook
  6. from mpl_toolkits.axisartist import Subplot
  7. from mpl_toolkits.axisartist import SubplotHost, \
  8.     ParasiteAxesAuxTrans
  9. from mpl_toolkits.axisartist.grid_helper_curvelinear import \
  10.     GridHelperCurveLinear
  13. def curvelinear_test1(fig):
  14.     """
  15.     grid for custom transform.
  16.     """
  18.     def tr(x, y):
  19.         x, y = np.asarray(x), np.asarray(y)
  20.         return x, y - x
  22.     def inv_tr(x, y):
  23.         x, y = np.asarray(x), np.asarray(y)
  24.         return x, y + x
  26.     grid_helper = GridHelperCurveLinear((tr, inv_tr))
  28.     ax1 = Subplot(fig, 1, 2, 1, grid_helper=grid_helper)
  29.     # ax1 will have a ticks and gridlines defined by the given
  30.     # transform (+ transData of the Axes). Note that the transform of
  31.     # the Axes itself (i.e., transData) is not affected by the given
  32.     # transform.
  34.     fig.add_subplot(ax1)
  36.     xx, yy = tr([3, 6], [5.0, 10.])
  37.     ax1.plot(xx, yy, linewidth=2.0)
  39.     ax1.set_aspect(1.)
  40.     ax1.set_xlim(0, 10.)
  41.     ax1.set_ylim(0, 10.)
  43.     ax1.axis["t"] = ax1.new_floating_axis(0, 3.)
  44.     ax1.axis["t2"] = ax1.new_floating_axis(1, 7.)
  45.     ax1.grid(True, zorder=0)
  48. import mpl_toolkits.axisartist.angle_helper as angle_helper
  50. from matplotlib.projections import PolarAxes
  51. from matplotlib.transforms import Affine2D
  54. def curvelinear_test2(fig):
  55.     """
  56.     polar projection, but in a rectangular box.
  57.     """
  59.     # PolarAxes.PolarTransform takes radian. However, we want our coordinate
  60.     # system in degree
  61.     tr = Affine2D().scale(np.pi/180., 1.) + PolarAxes.PolarTransform()
  63.     # polar projection, which involves cycle, and also has limits in
  64.     # its coordinates, needs a special method to find the extremes
  65.     # (min, max of the coordinate within the view).
  67.     # 20, 20 : number of sampling points along x, y direction
  68.     extreme_finder = angle_helper.ExtremeFinderCycle(20, 20,
  69.                                                      lon_cycle=360,
  70.                                                      lat_cycle=None,
  71.                                                      lon_minmax=None,
  72.                                                      lat_minmax=(0, np.inf),
  73.                                                      )
  75.     grid_locator1 = angle_helper.LocatorDMS(12)
  76.     # Find a grid values appropriate for the coordinate (degree,
  77.     # minute, second).
  79.     tick_formatter1 = angle_helper.FormatterDMS()
  80.     # And also uses an appropriate formatter.  Note that,the
  81.     # acceptable Locator and Formatter class is a bit different than
  82.     # that of mpl's, and you cannot directly use mpl's Locator and
  83.     # Formatter here (but may be possible in the future).
  85.     grid_helper = GridHelperCurveLinear(tr,
  86.                                         extreme_finder=extreme_finder,
  87.                                         grid_locator1=grid_locator1,
  88.                                         tick_formatter1=tick_formatter1
  89.                                         )
  91.     ax1 = SubplotHost(fig, 1, 2, 2, grid_helper=grid_helper)
  93.     # make ticklabels of right and top axis visible.
  94.     ax1.axis["right"].major_ticklabels.set_visible(True)
  95.     ax1.axis["top"].major_ticklabels.set_visible(True)
  97.     # let right axis shows ticklabels for 1st coordinate (angle)
  98.     ax1.axis["right"].get_helper().nth_coord_ticks = 0
  99.     # let bottom axis shows ticklabels for 2nd coordinate (radius)
  100.     ax1.axis["bottom"].get_helper().nth_coord_ticks = 1
  102.     fig.add_subplot(ax1)
  104.     # A parasite axes with given transform
  105.     ax2 = ParasiteAxesAuxTrans(ax1, tr, "equal")
  106.     # note that ax2.transData == tr + ax1.transData
  107.     # Anything you draw in ax2 will match the ticks and grids of ax1.
  108.     ax1.parasites.append(ax2)
  109.     intp = cbook.simple_linear_interpolation
  110.     ax2.plot(intp(np.array([0, 30]), 50),
  111.              intp(np.array([10., 10.]), 50),
  112.              linewidth=2.0)
  114.     ax1.set_aspect(1.)
  115.     ax1.set_xlim(-5, 12)
  116.     ax1.set_ylim(-5, 10)
  118.     ax1.grid(True, zorder=0)
  120. if 1:
  121.     fig = plt.figure(1, figsize=(7, 4))
  122.     fig.clf()
  124.     curvelinear_test1(fig)
  125.     curvelinear_test2(fig)
  127.     plt.show()

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