X-Git-Url: https://scm.cri.ensmp.fr/git/linpy.git/blobdiff_plain/5a5fd1db359b190c6207301eb08705a34367968a..2b13a146860ac116ce0388d8f7551044c09c55f7:/linpy/domains.py diff --git a/linpy/domains.py b/linpy/domains.py index 83f6c2c..432e275 100644 --- a/linpy/domains.py +++ b/linpy/domains.py @@ -24,7 +24,7 @@ from fractions import Fraction from . import islhelper from .islhelper import mainctx, libisl -from .linexprs import LinExpr, Symbol, Rational +from .linexprs import LinExpr, Symbol from .geometry import GeometricObject, Point, Vector @@ -38,7 +38,7 @@ __all__ = [ class Domain(GeometricObject): """ A domain is a union of polyhedra. Unlike polyhedra, domains allow exact - computation of union and complementary operations. + computation of union, subtraction and complementary operations. A domain with a unique polyhedron is automatically subclassed as a Polyhedron instance. @@ -54,22 +54,23 @@ class Domain(GeometricObject): """ Return a domain from a sequence of polyhedra. - >>> square = Polyhedron('0 <= x <= 2, 0 <= y <= 2') - >>> square2 = Polyhedron('2 <= x <= 4, 2 <= y <= 4') - >>> dom = Domain([square, square2]) + >>> square1 = Polyhedron('0 <= x <= 2, 0 <= y <= 2') + >>> square2 = Polyhedron('1 <= x <= 3, 1 <= y <= 3') + >>> dom = Domain(square1, square2) + >>> dom + Or(And(x <= 2, 0 <= x, y <= 2, 0 <= y), + And(x <= 3, 1 <= x, y <= 3, 1 <= y)) It is also possible to build domains from polyhedra using arithmetic - operators Domain.__and__(), Domain.__or__() or functions And() and Or(), - using one of the following instructions: + operators Domain.__or__(), Domain.__invert__() or functions Or() and + Not(), using one of the following instructions: - >>> square = Polyhedron('0 <= x <= 2, 0 <= y <= 2') - >>> square2 = Polyhedron('2 <= x <= 4, 2 <= y <= 4') - >>> dom = square | square2 - >>> dom = Or(square, square2) + >>> dom = square1 | square2 + >>> dom = Or(square1, square2) Alternatively, a domain can be built from a string: - >>> dom = Domain('0 <= x <= 2, 0 <= y <= 2; 2 <= x <= 4, 2 <= y <= 4') + >>> dom = Domain('0 <= x <= 2, 0 <= y <= 2; 1 <= x <= 3, 1 <= y <= 3') Finally, a domain can be built from a GeometricObject instance, calling the GeometricObject.asdomain() method. @@ -703,17 +704,17 @@ class Domain(GeometricObject): Create a domain from a string. Raise SyntaxError if the string is not properly formatted. """ - # remove curly brackets + # Remove curly brackets. string = cls._RE_BRACES.sub(r'', string) - # replace '=' by '==' + # Replace '=' by '=='. string = cls._RE_EQ.sub(r'\1==\2', string) - # replace 'and', 'or', 'not' + # Replace 'and', 'or', 'not'. string = cls._RE_AND.sub(r' & ', string) string = cls._RE_OR.sub(r' | ', string) string = cls._RE_NOT.sub(r' ~', string) - # add implicit multiplication operators, e.g. '5x' -> '5*x' + # Add implicit multiplication operators, e.g. '5x' -> '5*x'. string = cls._RE_NUM_VAR.sub(r'\1*\2', string) - # add parentheses to force precedence + # Add parentheses to force precedence. tokens = cls._RE_OPERATORS.split(string) for i, token in enumerate(tokens): if i % 2 == 0: @@ -728,16 +729,10 @@ class Domain(GeometricObject): strings = [repr(polyhedron) for polyhedron in self.polyhedra] return 'Or({})'.format(', '.join(strings)) - def _repr_latex_(self): - strings = [] - for polyhedron in self.polyhedra: - strings.append('({})'.format(polyhedron._repr_latex_().strip('\$'))) - return '\${}\$'.format(' \\vee '.join(strings)) - @classmethod def fromsympy(cls, expr): """ - Create a domain from a sympy expression. + Create a domain from a SymPy expression. """ import sympy from .polyhedra import Lt, Le, Eq, Ne, Ge, Gt @@ -756,7 +751,7 @@ class Domain(GeometricObject): def tosympy(self): """ - Convert the domain to a sympy expression. + Convert the domain to a SymPy expression. """ import sympy polyhedra = [polyhedron.tosympy() for polyhedron in polyhedra] @@ -772,7 +767,6 @@ def And(*domains): return Universe else: return domains[0].intersection(*domains[1:]) -And.__doc__ = Domain.intersection.__doc__ def Or(*domains): """ @@ -783,11 +777,9 @@ def Or(*domains): return Empty else: return domains[0].union(*domains[1:]) -Or.__doc__ = Domain.union.__doc__ def Not(domain): """ Create the complementary domain of the domain given in argument. """ return ~domain -Not.__doc__ = Domain.complement.__doc__