From b4bd8f7aa081b9296c6089310d286c3b7359a5cc Mon Sep 17 00:00:00 2001 From: Vivien Maisonneuve Date: Tue, 19 Aug 2014 17:52:59 +0200 Subject: [PATCH] Improve functions Lt, Le, Eq, Ne, Ge, Gt --- doc/reference.rst | 2 +- linpy/polyhedra.py | 82 +++++++++++++++++++++++++++------------------- 2 files changed, 49 insertions(+), 35 deletions(-) diff --git a/doc/reference.rst b/doc/reference.rst index 69f0f45..e649227 100644 --- a/doc/reference.rst +++ b/doc/reference.rst @@ -505,7 +505,7 @@ The following functions create :class:`Polyhedron` or :class:`Domain` instances .. function:: Ne(expr1, expr2[, expr3, ...]) Create the domain such that ``expr1 != expr2 != expr3 ...``. - The result is a :class:`Domain`, not a :class:`Polyhedron`. + The result is a :class:`Domain` object, not a :class:`Polyhedron`. .. function:: Ge(expr1, expr2[, expr3, ...]) diff --git a/linpy/polyhedra.py b/linpy/polyhedra.py index b88cfd1..a720b74 100644 --- a/linpy/polyhedra.py +++ b/linpy/polyhedra.py @@ -364,63 +364,77 @@ class UniverseType(Polyhedron): Universe = UniverseType() -def _polymorphic(func): +def _pseudoconstructor(func): @functools.wraps(func) - def wrapper(left, right): - if not isinstance(left, LinExpr): - if isinstance(left, numbers.Rational): - left = Rational(left) - else: - raise TypeError('left must be a a rational number ' - 'or a linear expression') - if not isinstance(right, LinExpr): - if isinstance(right, numbers.Rational): - right = Rational(right) - else: - raise TypeError('right must be a a rational number ' - 'or a linear expression') - return func(left, right) + def wrapper(expr1, expr2, *exprs): + exprs = (expr1, expr2) + exprs + for expr in exprs: + if not isinstance(expr, LinExpr): + if isinstance(expr, numbers.Rational): + expr = Rational(expr) + else: + raise TypeError('arguments must be rational numbers ' + 'or linear expressions') + return func(*exprs) return wrapper -@_polymorphic -def Lt(left, right): +@_pseudoconstructor +def Lt(*exprs): """ Create the polyhedron with constraints expr1 < expr2 < expr3 ... """ - return Polyhedron([], [right - left - 1]) + inequalities = [] + for left, right in zip(exprs, exprs[1:]): + inequalities.append(right - left - 1) + return Polyhedron([], inequalities) -@_polymorphic -def Le(left, right): +@_pseudoconstructor +def Le(*exprs): """ Create the polyhedron with constraints expr1 <= expr2 <= expr3 ... """ - return Polyhedron([], [right - left]) + inequalities = [] + for left, right in zip(exprs, exprs[1:]): + inequalities.append(right - left) + return Polyhedron([], inequalities) -@_polymorphic -def Eq(left, right): +@_pseudoconstructor +def Eq(*exprs): """ Create the polyhedron with constraints expr1 == expr2 == expr3 ... """ - return Polyhedron([left - right], []) + equalities = [] + for left, right in zip(exprs, exprs[1:]): + equalities.append(left - right) + return Polyhedron(equalities, []) -@_polymorphic -def Ne(left, right): +@_pseudoconstructor +def Ne(*exprs): """ Create the domain such that expr1 != expr2 != expr3 ... The result is a - Domain, not a Polyhedron. + Domain object, not a Polyhedron. """ - return ~Eq(left, right) + domain = Universe + for left, right in zip(exprs, exprs[1:]): + domain &= ~Eq(left, right) + return domain -@_polymorphic -def Ge(left, right): +@_pseudoconstructor +def Ge(*exprs): """ Create the polyhedron with constraints expr1 >= expr2 >= expr3 ... """ - return Polyhedron([], [left - right]) + inequalities = [] + for left, right in zip(exprs, exprs[1:]): + inequalities.append(left - right) + return Polyhedron([], inequalities) -@_polymorphic -def Gt(left, right): +@_pseudoconstructor +def Gt(*exprs): """ Create the polyhedron with constraints expr1 > expr2 > expr3 ... """ - return Polyhedron([], [left - right - 1]) + inequalities = [] + for left, right in zip(exprs, exprs[1:]): + inequalities.append(left - right - 1) + return Polyhedron([], inequalities) -- 2.20.1