axes_grid: initial checkin of curvelinear grid support

svn path=/trunk/matplotlib/; revision=7175

Author: leejjoon

CHANGELOG

@@ -1,3 +1,6 @@
+2009-06-03 axes_grid : Initial check-in of curvelinear grid support. See 
+           examples/axes_grid/demo_curvelinear_grid.py - JJL
+
 2009-06-01 Spine is now derived from Patch - ADS
 
 2009-06-01 use cbook.is_string_like() instead of isinstance() for spines - ADS

examples/axes_grid/demo_curvelinear_grid.py

@@ -0,0 +1,131 @@
+import numpy as np
+#from matplotlib.path import Path
+
+import matplotlib.pyplot as plt
+import matplotlib.cbook as cbook
+
+from  mpl_toolkits.axes_grid.grid_helper_curvelinear import GridHelperCurveLinear
+from mpl_toolkits.axes_grid.axislines import Subplot
+
+from mpl_toolkits.axes_grid.parasite_axes import SubplotHost, \
+     ParasiteAxesAuxTrans
+
+
+def curvelinear_test1(fig):
+    """
+    grid for custom transform.
+    """
+
+    def tr(x, y):
+        x, y = np.asarray(x), np.asarray(y)
+        return x, y-x
+
+    def inv_tr(x,y):
+        x, y = np.asarray(x), np.asarray(y)
+        return x, y+x
+
+
+    grid_helper = GridHelperCurveLinear((tr, inv_tr))
+
+    ax1 = Subplot(fig, 1, 2, 1, grid_helper=grid_helper)
+    # ax1 will have a ticks and gridlines defined by the given
+    # transform (+ transData of the Axes). Note that the transform of
+    # the Axes itself (i.e., transData) is not affected by the given
+    # transform.
+
+    fig.add_subplot(ax1)
+
+    xx, yy = tr([3, 6], [5.0, 10.])
+    ax1.plot(xx, yy)
+
+    ax1.set_aspect(1.)
+    ax1.set_xlim(0, 10.)
+    ax1.set_ylim(0, 10.)
+
+    ax1.grid(True)
+
+
+
+import  mpl_toolkits.axes_grid.angle_helper as angle_helper
+from matplotlib.projections import PolarAxes
+from matplotlib.transforms import Affine2D
+
+def curvelinear_test2(fig):
+    """
+    polar projection, but in a rectangular box.
+    """
+
+    # PolarAxes.PolarTransform takes radian. However, we want our coordinate
+    # system in degree
+    tr = Affine2D().scale(np.pi/180., 1.) + PolarAxes.PolarTransform()
+
+    # polar projection, which involves cycle, and also has limits in
+    # its coordinates, needs a special method to find the extremes
+    # (min, max of the coordinate within the view).
+
+    # 20, 20 : number of sampling points along x, y direction
+    extreme_finder = angle_helper.ExtremeFinderCycle(20, 20,
+                                                     lon_cycle = 360,
+                                                     lat_cycle = None,
+                                                     lon_minmax = None,
+                                                     lat_minmax = (0, np.inf),
+                                                     )
+
+    grid_locator1 = angle_helper.LocatorDMS(12)
+    # Find a grid values appropriate for the coordinate (degree,
+    # minute, second).
+
+    tick_formatter1 = angle_helper.FormatterDMS()
+    # And also uses an appropriate formatter.  Note that,the
+    # acceptable Locator and Formatter class is a bit different than
+    # that of mpl's, and you cannot directly use mpl's Locator and
+    # Formatter here (but may be possible in the future).
+
+    grid_helper = GridHelperCurveLinear(tr,
+                                        extreme_finder=extreme_finder,
+                                        grid_locator1=grid_locator1,
+                                        tick_formatter1=tick_formatter1
+                                        )
+
+
+    ax1 = SubplotHost(fig, 1, 2, 2, grid_helper=grid_helper)
+
+    # make ticklabels of right and top axis visible.
+    ax1.axis["right"].major_ticklabels.set_visible(True)
+    ax1.axis["top"].major_ticklabels.set_visible(True)
+
+    # let right axis shows ticklabels for 1st coordinate (angle)
+    ax1.axis["right"].get_helper().nth_coord_ticks=0
+    # let bottom axis shows ticklabels for 2nd coordinate (radius)
+    ax1.axis["bottom"].get_helper().nth_coord_ticks=1
+
+    fig.add_subplot(ax1)
+
+
+    # A parasite axes with given transform
+    ax2 = ParasiteAxesAuxTrans(ax1, tr, "equal")
+    # note that ax2.transData == tr + ax1.transData
+    # Anthing you draw in ax2 will match the ticks and grids of ax1.
+    ax1.parasites.append(ax2)
+    intp = cbook.simple_linear_interpolation
+    ax2.plot(intp(np.array([0, 30]), 50),
+             intp(np.array([10., 10.]), 50))
+
+    ax1.set_aspect(1.)
+    ax1.set_xlim(-5, 12)
+    ax1.set_ylim(-5, 10)
+
+    ax1.grid(True)
+
+if 1:
+    fig = plt.figure(1, figsize=(7, 4))
+    fig.clf()
+
+    curvelinear_test1(fig)
+    curvelinear_test2(fig)
+
+    plt.draw()
+    plt.show()
+
+
+

lib/mpl_toolkits/axes_grid/ChangeLog

@@ -1,6 +1,7 @@
 2009-06-01  Jae-Joon Lee  <lee.j.joon@gmail.com>
 
 	* axislines.py (Axes.toggle_axisline): fix broken spine support.
+	(AxisArtistHelper): Initial support for curvelinear grid and ticks.
 
 2009-05-04  Jae-Joon Lee  <lee.j.joon@gmail.com>