Fix 3d plots in examples

[linpy.git] / doc / tutorial.rst

diff --git a/doc/tutorial.rst b/doc/tutorial.rst
index 9b55a03..67aecd6 100644 (file)
--- a/doc/tutorial.rst
+++ b/doc/tutorial.rst
@@ -10,8 +10,8 @@ For a comprehensive description of its functionalities, please consult the :ref:
 
 .. _tutorial_polyhedra:
 
-Polyhedra
----------
+Z-Polyhedra
+-----------
 
 The following example shows how we can manipulate polyhedra using LinPy.
 Let us define two square polyhedra, corresponding to the sets ``square1 = {(x, y) | 0 <= x <= 2, 0 <= y <= 2}`` and ``square2 = {(x, y) | 2 <= x <= 4, 2 <= y <= 4}``.
@@ -24,31 +24,32 @@ Then, we can build the :class:`Polyhedron` object ``square1`` from its constrain
 
 >>> square1 = Le(0, x, 2) & Le(0, y, 2)
 >>> square1
-And(Ge(x, 0), Ge(-x + 2, 0), Ge(y, 0), Ge(-y + 2, 0))
+And(0 <= x, x <= 2, 0 <= y, y <= 2)
 
 LinPy provides comparison functions :func:`Lt`, :func:`Le`, :func:`Eq`, :func:`Ne`, :func:`Ge` and :func:`Gt` to build constraints, and logical operators :func:`And`, :func:`Or`, :func:`Not` to combine them.
 Alternatively, a polyhedron can be built from a string:
 
 >>> square2 = Polyhedron('1 <= x <= 3, 1 <= y <= 3')
 >>> square2
-And(Ge(x - 1, 0), Ge(-x + 3, 0), Ge(y - 1, 0), Ge(-y + 3, 0))
+And(1 <= x, x <= 3, 1 <= y, y <= 3)
 
 The usual polyhedral operations are available, including intersection:
 
->>> inter = square1.intersection(square2)
+>>> inter = square1.intersection(square2) # or square1 & square2
 >>> inter
-And(Ge(x - 1, 0), Ge(-x + 2, 0), Ge(y - 1, 0), Ge(-y + 2, 0))
+And(1 <= x, x <= 2, 1 <= y, y <= 2)
 
 convex union:
 
 >>> hull = square1.convex_union(square2)
 >>> hull
-And(Ge(x, 0), Ge(y, 0), Ge(-x + y + 2, 0), Ge(x - y + 2, 0), Ge(-x + 3, 0), Ge(-y + 3, 0))
+And(0 <= x, 0 <= y, x <= y + 2, y <= x + 2, x <= 3, y <= 3)
 
 and projection:
 
->>> square1.project([y])
-And(Ge(x, 0), Ge(-x + 2, 0))
+>>> proj = square1.project([y])
+>>> proj
+And(0 <= x, x <= 2)
 
 Equality and inclusion tests are also provided.
 Special values :data:`Empty` and :data:`Universe` represent the empty and universe polyhedra.
@@ -68,19 +69,19 @@ LinPy is also able to manipulate polyhedral *domains*, that is, unions of polyhe
 An example of domain is the set union (as opposed to convex union) of polyhedra ``square1`` and ``square2``.
 The result is a :class:`Domain` object.
 
->>> union = square1 | square2
+>>> union = square1.union(square2) # or square1 | square2
 >>> union
-Or(And(Ge(-x + 2, 0), Ge(x, 0), Ge(-y + 2, 0), Ge(y, 0)), And(Ge(-x + 3, 0), Ge(x - 1, 0), Ge(-y + 3, 0), Ge(y - 1, 0)))
+Or(And(x <= 2, 0 <= x, y <= 2, 0 <= y), And(x <= 3, 1 <= x, y <= 3, 1 <= y))
 >>> union <= hull
 True
 
 Unlike polyhedra, domains allow exact computation of union, subtraction and complementary operations.
 
->>> diff = square1 - square2
+>>> diff = square1.difference(square2) # or square1 - square2
 >>> diff
-Or(And(Eq(x, 0), Ge(y, 0), Ge(-y + 2, 0)), And(Eq(y, 0), Ge(x - 1, 0), Ge(-x + 2, 0)))
+Or(And(x == 0, 0 <= y, y <= 2), And(y == 0, 1 <= x, x <= 2))
 >>> ~square1
-Or(Ge(-x - 1, 0), Ge(x - 3, 0), And(Ge(x, 0), Ge(-x + 2, 0), Ge(-y - 1, 0)), And(Ge(x, 0), Ge(-x + 2, 0), Ge(y - 3, 0)))
+Or(x + 1 <= 0, 3 <= x, And(0 <= x, x <= 2, y + 1 <= 0), And(0 <= x, x <= 2, 3 <= y))
 
 
 .. _tutorial_plot: