X-Git-Url: https://scm.cri.ensmp.fr/git/linpy.git/blobdiff_plain/997e3c68590b274c372a6785cda5a69887683891..98edd00eb4b05e85f7cb1b85cff2f4d733909c57:/doc/examples.rst diff --git a/doc/examples.rst b/doc/examples.rst deleted file mode 100644 index 13c59fc..0000000 --- a/doc/examples.rst +++ /dev/null @@ -1,96 +0,0 @@ -LinPy Examples -============== - -Basic Examples -------------- - To create any polyhedron, first define the symbols used. Then use the polyhedron functions to define the constraints. The following is a simple running example illustrating some different operations and properties that can be performed by LinPy with two squares. - - >>> from linpy import * - >>> x, y = symbols('x y') - >>> # define the constraints of the polyhedron - >>> square1 = Le(0, x) & Le(x, 2) & Le(0, y) & Le(y, 2) - >>> print(square1) - And(Ge(x, 0), Ge(-x + 2, 0), Ge(y, 0), Ge(-y + 2, 0)) - - Binary operations and properties examples: - - >>> square2 = Le(2, x) & Le(x, 4) & Le(2, y) & Le(y, 4) - >>> #test equality - >>> square1 == square2 - False - >>> # compute the union of two polygons - >>> square1 | square2 - Or(And(Ge(x, 0), Ge(-x + 2, 0), Ge(y, 0), Ge(-y + 2, 0)), And(Ge(x - 2, 0), Ge(-x + 4, 0), Ge(y - 2, 0), Ge(-y + 4, 0))) - >>> # check if square1 and square2 are disjoint - >>> square1.disjoint(square2) - False - >>> # compute the intersection of two polygons - >>> square1 & square2 - And(Eq(y - 2, 0), Eq(x - 2, 0)) - >>> # compute the convex union of two polygons - >>> Polyhedron(square1 | sqaure2) - And(Ge(x, 0), Ge(-x + 4, 0), Ge(y, 0), Ge(-y + 4, 0), Ge(x - y + 2, 0), Ge(-x + y + 2, 0)) - - Unary operation and properties examples: - - >>> square1.isempty() - False - >>> square1.symbols() - (x, y) - >>> square1.inequalities - (x, -x + 2, y, -y + 2) - >>> # project out the variable x - >>> square1.project([x]) - And(Ge(-y + 2, 0), Ge(y, 0)) - -Plot Examples -------------- - - LinPy uses matplotlib plotting library to plot 2D and 3D polygons. The user has the option to pass subplots to the :meth:`plot` method. This can be a useful tool to compare polygons. Also, key word arguments can be passed such as color and the degree of transparency of a polygon. - - >>> import matplotlib.pyplot as plt - >>> from matplotlib import pylab - >>> from mpl_toolkits.mplot3d import Axes3D - >>> from linpy import * - >>> # define the symbols - >>> x, y, z = symbols('x y z') - >>> fig = plt.figure() - >>> cham_plot = fig.add_subplot(2, 2, 3, projection='3d') - >>> cham_plot.set_title('Chamfered cube') - >>> cham = Le(0, x) & Le(x, 3) & Le(0, y) & Le(y, 3) & Le(0, z) & Le(z, 3) & Le(z - 2, x) & Le(x, z + 2) & Le(1 - z, x) & Le(x, 5 - z) & Le(z - 2, y) & Le(y, z + 2) & Le(1 - z, y) & Le(y, 5 - z) & Le(y - 2, x) & Le(x, y + 2) & Le(1 - y, x) & Le(x, 5 - y) - >>> cham.plot(cham_plot, facecolors=(1, 0, 0, 0.75)) - >>> pylab.show() - - .. figure:: images/cube.jpg - :align: center - - LinPy can also inspect a polygon's vertices and the integer points included in the polygon. - - >>> diamond = Ge(y, x - 1) & Le(y, x + 1) & Ge(y, -x - 1) & Le(y, -x + 1) - >>> diamond.vertices() - [Point({x: Fraction(0, 1), y: Fraction(1, 1)}), Point({x: Fraction(-1, 1), y: Fraction(0, 1)}), Point({x: Fraction(1, 1), y: Fraction(0, 1)}), Point({x: Fraction(0, 1), y: Fraction(-1, 1)})] - >>> diamond.points() - [Point({x: -1, y: 0}), Point({x: 0, y: -1}), Point({x: 0, y: 0}), Point({x: 0, y: 1}), Point({x: 1, y: 0})] - - The user also can pass another plot to the :meth:`plot` method. This can be useful to compare two polyhedrons on the same axis. This example illustrates the union of two squares. - - >>> from linpy import * - >>> import matplotlib.pyplot as plt - >>> from matplotlib import pylab - >>> x, y = symbols('x y') - >>> square1 = Le(0, x) & Le(x, 2) & Le(0, y) & Le(y, 2) - >>> square2 = Le(1, x) & Le(x, 3) & Le(1, y) & Le(y, 3) - >>> fig = plt.figure() - >>> plot = fig.add_subplot(1, 1, 1, aspect='equal') - >>> square1.plot(plot, facecolor='red', alpha=0.3) - >>> square2.plot(plot, facecolor='blue', alpha=0.3) - >>> squares = Polyhedron(square1 + square2) - >>> squares.plot(plot, facecolor='blue', alpha=0.3) - >>> pylab.show() - - .. figure:: images/union.jpg - :align: center - - - -