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ianthomas23ianthomas23
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Added TriFinder and TrapezoidMapTriFinder classes.
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Lines changed: 1806 additions & 27 deletions

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‎doc/api/tri_api.rst‎

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:mod:`matplotlib.tri`
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=====================
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.. automodule:: matplotlib.tri
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:members: Triangulation
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.. autoclass:: matplotlib.tri.Triangulation
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:members:
1010

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.. autoclass:: matplotlib.tri.TriFinder
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:members:
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.. autoclass:: matplotlib.tri.TrapezoidMapTriFinder
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:members: __call__

‎examples/event_handling/trifinder_event_demo.py‎

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"""
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Example showing the use of a TriFinder object. As the mouse is moved over the
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triangulation, the triangle under the cursor is highlighted and the index of
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the triangle is displayed in the plot title.
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"""
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import matplotlib.pyplot as plt
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from matplotlib.tri import Triangulation
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from matplotlib.patches import Polygon
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import numpy as np
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import math
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def update_polygon(tri):
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if tri == -1:
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points = [0, 0, 0]
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else:
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points = triangulation.triangles[tri]
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xs = triangulation.x[points]
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ys = triangulation.y[points]
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polygon.set_xy(zip(xs, ys))
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def motion_notify(event):
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if event.inaxes is None:
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tri = -1
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else:
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tri = trifinder(event.xdata, event.ydata)
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update_polygon(tri)
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plt.title('In triangle %i' % tri)
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event.canvas.draw()
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# Create a Triangulation.
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n_angles = 16
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n_radii = 5
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min_radius = 0.25
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radii = np.linspace(min_radius, 0.95, n_radii)
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angles = np.linspace(0, 2*math.pi, n_angles, endpoint=False)
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angles = np.repeat(angles[..., np.newaxis], n_radii, axis=1)
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angles[:, 1::2] += math.pi / n_angles
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x = (radii*np.cos(angles)).flatten()
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y = (radii*np.sin(angles)).flatten()
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triangulation = Triangulation(x, y)
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xmid = x[triangulation.triangles].mean(axis=1)
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ymid = y[triangulation.triangles].mean(axis=1)
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mask = np.where(xmid*xmid + ymid*ymid < min_radius*min_radius, 1, 0)
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triangulation.set_mask(mask)
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# Use the triangulation's default TriFinder object.
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trifinder = triangulation.get_trifinder()
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# Setup plot and callbacks.
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plt.subplot(111, aspect='equal')
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plt.triplot(triangulation, 'bo-')
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polygon = Polygon([[0, 0], [0, 0]], facecolor='y') # dummy data for xs,ys
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update_polygon(-1)
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plt.gca().add_patch(polygon)
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plt.gcf().canvas.mpl_connect('motion_notify_event', motion_notify)
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plt.show()

‎lib/matplotlib/tests/test_triangulation.py‎

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@@ -131,3 +131,91 @@ def test_no_modify():
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tri = mtri.Triangulation(points[:,0], points[:,1], triangles)
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edges = tri.edges
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assert_array_equal(old_triangles, triangles)
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def test_trifinder():
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# Test points within triangles of masked triangulation.
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x,y = np.meshgrid(np.arange(4), np.arange(4))
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x = x.ravel()
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y = y.ravel()
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triangles = [[0,1,4], [1,5,4], [1,2,5], [2,6,5], [2,3,6], [3,7,6], [4,5,8],
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[5,9,8], [5,6,9], [6,10,9], [6,7,10], [7,11,10], [8,9,12],
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[9,13,12], [9,10,13], [10,14,13], [10,11,14], [11,15,14]]
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mask = np.zeros(len(triangles))
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mask[8:10] = 1
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triang = mtri.Triangulation(x, y, triangles, mask)
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trifinder = triang.get_trifinder()
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xs = [0.25, 1.25, 2.25, 3.25]
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ys = [0.25, 1.25, 2.25, 3.25]
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xs,ys = np.meshgrid(xs,ys)
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xs = xs.ravel()
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ys = ys.ravel()
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [0,2,4,-1,6,-1,10,-1,12,14,16,-1,-1,-1,-1,-1])
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tris = trifinder(xs-0.5, ys-0.5)
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assert_array_equal(tris, [-1,-1,-1,-1,-1,1,3,5,-1,7,-1,11,-1,13,15,17])
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# Test points exactly on boundary edges of masked triangulation.
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xs = [0.5, 1.5, 2.5, 0.5, 1.5, 2.5, 1.5, 1.5, 0.0, 1.0, 2.0, 3.0]
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ys = [0.0, 0.0, 0.0, 3.0, 3.0, 3.0, 1.0, 2.0, 1.5, 1.5, 1.5, 1.5]
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [0,2,4,13,15,17,3,14,6,7,10,11])
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# Test points exactly on boundary corners of masked triangulation.
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xs = [0.0, 3.0]
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ys = [0.0, 3.0]
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [0,17])
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# Test triangles with horizontal colinear points. These are not valid
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# triangulations, but we try to deal with the simplest violations.
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delta = 0.0 # If +ve, triangulation is OK, if -ve triangulation invalid,
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# if zero have colinear points but should pass tests anyway.
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x = [1.5, 0, 1, 2, 3, 1.5, 1.5]
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y = [-1, 0, 0, 0, 0, delta, 1]
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triangles = [[0,2,1], [0,3,2], [0,4,3], [1,2,5], [2,3,5], [3,4,5], [1,5,6],
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[4,6,5]]
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triang = mtri.Triangulation(x, y, triangles)
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trifinder = triang.get_trifinder()
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xs = [-0.1, 0.4, 0.9, 1.4, 1.9, 2.4, 2.9]
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ys = [-0.1,0.1]
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xs,ys = np.meshgrid(xs, ys)
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [[-1,0,0,1,1,2,-1],[-1,6,6,6,7,7,-1]])
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# Test triangles with vertical colinear points. These are not valid
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# triangulations, but we try to deal with the simplest violations.
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delta = 0.0 # If +ve, triangulation is OK, if -ve triangulation invalid,
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# if zero have colinear points but should pass tests anyway.
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x = [-1, -delta, 0, 0, 0, 0, 1]
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y = [1.5, 1.5, 0, 1, 2, 3, 1.5]
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triangles = [[0,1,2], [0,1,5], [1,2,3], [1,3,4], [1,4,5], [2,6,3], [3,6,4],
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[4,6,5]]
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triang = mtri.Triangulation(x, y, triangles)
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trifinder = triang.get_trifinder()
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xs = [-0.1,0.1]
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ys = [-0.1, 0.4, 0.9, 1.4, 1.9, 2.4, 2.9]
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xs,ys = np.meshgrid(xs, ys)
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [[-1,-1], [0,5], [0,5], [0,6], [1,6], [1,7],
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[-1,-1]])
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# Test that changing triangulation by setting a mask causes the trifinder
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# to be reinitialised.
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x = [0, 1, 0, 1]
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y = [0, 0, 1, 1]
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triangles = [[0,1,2], [1,3,2]]
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triang = mtri.Triangulation(x, y, triangles)
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trifinder = triang.get_trifinder()
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xs = [-0.2, 0.2, 0.8, 1.2]
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ys = [0.5, 0.5, 0.5, 0.5]
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [-1, 0, 1, -1])
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triang.set_mask([1, 0])
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assert_equal(trifinder, triang.get_trifinder())
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tris = trifinder(xs, ys)
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assert_array_equal(tris, [-1, -1, 1, -1])

‎lib/matplotlib/tri/__init__.py‎

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from __future__ import print_function
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from triangulation import *
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from tricontour import *
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from trifinder import *
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from tripcolor import *
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from triplot import *

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