return Rational(constant)
if isinstance(coefficients, Mapping):
coefficients = coefficients.items()
+ coefficients = list(coefficients)
for symbol, coefficient in coefficients:
if not isinstance(symbol, Symbol):
raise TypeError('symbols must be Symbol instances')
if not isinstance(coefficient, numbers.Rational):
- raise TypeError('coefficients must be Rational instances')
- coefficients = [(symbol, Fraction(coefficient))
- for symbol, coefficient in coefficients if coefficient != 0]
+ raise TypeError('coefficients must be rational numbers')
if not isinstance(constant, numbers.Rational):
- raise TypeError('constant must be a Rational instance')
- constant = Fraction(constant)
+ raise TypeError('constant must be a rational number')
if len(coefficients) == 0:
return Rational(constant)
if len(coefficients) == 1 and constant == 0:
symbol, coefficient = coefficients[0]
if coefficient == 1:
return symbol
+ coefficients = [(symbol, Fraction(coefficient))
+ for symbol, coefficient in coefficients if coefficient != 0]
+ coefficients.sort(key=lambda item: item[0].sortkey())
self = object().__new__(cls)
- self._coefficients = OrderedDict(sorted(coefficients,
- key=lambda item: item[0].sortkey()))
- self._constant = constant
+ self._coefficients = OrderedDict(coefficients)
+ self._constant = Fraction(constant)
self._symbols = tuple(self._coefficients)
self._dimension = len(self._symbols)
return self
def coefficient(self, symbol):
if not isinstance(symbol, Symbol):
raise TypeError('symbol must be a Symbol instance')
- try:
- return Rational(self._coefficients[symbol])
- except KeyError:
- return Rational(0)
+ return Rational(self._coefficients.get(symbol, 0))
__getitem__ = coefficient
constant = self._constant - other._constant
return Expression(coefficients, constant)
+ @_polymorphic
def __rsub__(self, other):
- return -(self - other)
+ return other - self
- @_polymorphic
def __mul__(self, other):
- if isinstance(other, Rational):
- return other.__rmul__(self)
+ if isinstance(other, numbers.Rational):
+ coefficients = ((symbol, coefficient * other)
+ for symbol, coefficient in self._coefficients.items())
+ constant = self._constant * other
+ return Expression(coefficients, constant)
return NotImplemented
__rmul__ = __mul__
- @_polymorphic
def __truediv__(self, other):
- if isinstance(other, Rational):
- return other.__rtruediv__(self)
+ if isinstance(other, numbers.Rational):
+ coefficients = ((symbol, coefficient / other)
+ for symbol, coefficient in self._coefficients.items())
+ constant = self._constant / other
+ return Expression(coefficients, constant)
return NotImplemented
- __rtruediv__ = __truediv__
-
@_polymorphic
def __eq__(self, other):
- # "normal" equality
+ # returns a boolean, not a constraint
# see http://docs.sympy.org/dev/tutorial/gotchas.html#equals-signs
return isinstance(other, Expression) and \
self._coefficients == other._coefficients and \
self._constant == other._constant
- @_polymorphic
def __le__(self, other):
from .polyhedra import Le
return Le(self, other)
- @_polymorphic
def __lt__(self, other):
from .polyhedra import Lt
return Lt(self, other)
- @_polymorphic
def __ge__(self, other):
from .polyhedra import Ge
return Ge(self, other)
- @_polymorphic
def __gt__(self, other):
from .polyhedra import Gt
return Gt(self, other)
string = ''
for i, (symbol, coefficient) in enumerate(self.coefficients()):
if coefficient == 1:
- string += '' if i == 0 else ' + '
- string += '{!r}'.format(symbol)
+ if i != 0:
+ string += ' + '
elif coefficient == -1:
string += '-' if i == 0 else ' - '
- string += '{!r}'.format(symbol)
+ elif i == 0:
+ string += '{}*'.format(coefficient)
+ elif coefficient > 0:
+ string += ' + {}*'.format(coefficient)
else:
- if i == 0:
- string += '{}*{!r}'.format(coefficient, symbol)
- elif coefficient > 0:
- string += ' + {}*{!r}'.format(coefficient, symbol)
- else:
- string += ' - {}*{!r}'.format(-coefficient, symbol)
+ string += ' - {}*'.format(-coefficient)
+ string += '{}'.format(symbol)
constant = self.constant
if len(string) == 0:
string += '{}'.format(constant)
string += ' - {}'.format(-constant)
return string
+ def _repr_latex_(self):
+ string = ''
+ for i, (symbol, coefficient) in enumerate(self.coefficients()):
+ if coefficient == 1:
+ if i != 0:
+ string += ' + '
+ elif coefficient == -1:
+ string += '-' if i == 0 else ' - '
+ elif i == 0:
+ string += '{}'.format(coefficient._repr_latex_().strip('$'))
+ elif coefficient > 0:
+ string += ' + {}'.format(coefficient._repr_latex_().strip('$'))
+ elif coefficient < 0:
+ string += ' - {}'.format((-coefficient)._repr_latex_().strip('$'))
+ string += '{}'.format(symbol._repr_latex_().strip('$'))
+ constant = self.constant
+ if len(string) == 0:
+ string += '{}'.format(constant._repr_latex_().strip('$'))
+ elif constant > 0:
+ string += ' + {}'.format(constant._repr_latex_().strip('$'))
+ elif constant < 0:
+ string += ' - {}'.format((-constant)._repr_latex_().strip('$'))
+ return '$${}$$'.format(string)
+
def _parenstr(self, always=False):
string = str(self)
if not always and (self.isconstant() or self.issymbol()):
raise TypeError('name must be a string')
self = object().__new__(cls)
self._name = name.strip()
- self._coefficients = {self: 1}
- self._constant = 0
+ self._coefficients = {self: Fraction(1)}
+ self._constant = Fraction(0)
self._symbols = (self,)
self._dimension = 1
return self
return True
def __eq__(self, other):
- return not isinstance(other, Dummy) and isinstance(other, Symbol) \
- and self.name == other.name
+ return self.sortkey() == other.sortkey()
def asdummy(self):
return Dummy(self.name)
def __repr__(self):
return self.name
+ def _repr_latex_(self):
+ return '$${}$$'.format(self.name)
+
@classmethod
def fromsympy(cls, expr):
import sympy
- if isinstance(expr, sympy.Symbol):
- return cls(expr.name)
+ if isinstance(expr, sympy.Dummy):
+ return Dummy(expr.name)
+ elif isinstance(expr, sympy.Symbol):
+ return Symbol(expr.name)
else:
raise TypeError('expr must be a sympy.Symbol instance')
def __new__(cls, name=None):
if name is None:
name = 'Dummy_{}'.format(Dummy._count)
+ elif not isinstance(name, str):
+ raise TypeError('name must be a string')
self = object().__new__(cls)
self._index = Dummy._count
self._name = name.strip()
- self._coefficients = {self: 1}
- self._constant = 0
+ self._coefficients = {self: Fraction(1)}
+ self._constant = Fraction(0)
self._symbols = (self,)
self._dimension = 1
Dummy._count += 1
def sortkey(self):
return self._name, self._index
- def __eq__(self, other):
- return isinstance(other, Dummy) and self._index == other._index
-
def __repr__(self):
return '_{}'.format(self.name)
+ def _repr_latex_(self):
+ return '$${}_{{{}}}$$'.format(self.name, self._index)
+
def symbols(names):
if isinstance(names, str):
def __bool__(self):
return Fraction.__bool__(self)
- @_polymorphic
- def __mul__(self, other):
- coefficients = dict(other._coefficients)
- for symbol in coefficients:
- coefficients[symbol] *= self._constant
- constant = other._constant * self._constant
- return Expression(coefficients, constant)
-
- __rmul__ = __mul__
-
- @_polymorphic
- def __rtruediv__(self, other):
- coefficients = dict(other._coefficients)
- for symbol in coefficients:
- coefficients[symbol] /= self._constant
- constant = other._constant / self._constant
- return Expression(coefficients, constant)
-
- @classmethod
- def fromstring(cls, string):
- if not isinstance(string, str):
- raise TypeError('string must be a string instance')
- return Rational(Fraction(string))
+ def __repr__(self):
+ if self.denominator == 1:
+ return '{!r}'.format(self.numerator)
+ else:
+ return '{!r}/{!r}'.format(self.numerator, self.denominator)
+
+ def _repr_latex_(self):
+ if self.denominator == 1:
+ return '$${}$$'.format(self.numerator)
+ elif self.numerator < 0:
+ return '$$-\\frac{{{}}}{{{}}}$$'.format(-self.numerator,
+ self.denominator)
+ else:
+ return '$$\\frac{{{}}}{{{}}}$$'.format(self.numerator,
+ self.denominator)
@classmethod
def fromsympy(cls, expr):
projects / linpy.git / blobdiff