X-Git-Url: https://scm.cri.mines-paristech.fr/git/linpy.git/blobdiff_plain/b2931230a184025bdb6006bfe48c9b1dc18dc351..1044e58e639333d281d47739ba9ecef607ff14e6:/linpy/linexprs.py diff --git a/linpy/linexprs.py b/linpy/linexprs.py index eff4a7e..f361218 100644 --- a/linpy/linexprs.py +++ b/linpy/linexprs.py @@ -306,7 +306,7 @@ class LinExpr: for symbol in substitutions: if not isinstance(symbol, Symbol): raise TypeError('symbols must be Symbol instances') - result = self._constant + result = Rational(self._constant) for symbol, coefficient in self._coefficients.items(): expression = substitutions.get(symbol, symbol) result += coefficient * expression @@ -348,10 +348,10 @@ class LinExpr: # Add implicit multiplication operators, e.g. '5x' -> '5*x'. string = LinExpr._RE_NUM_VAR.sub(r'\1*\2', string) tree = ast.parse(string, 'eval') - expr = cls._fromast(tree) - if not isinstance(expr, cls): + expression = cls._fromast(tree) + if not isinstance(expression, cls): raise SyntaxError('invalid syntax') - return expr + return expression def __repr__(self): string = '' @@ -377,30 +377,6 @@ class LinExpr: 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()): @@ -409,7 +385,7 @@ class LinExpr: return '({})'.format(string) @classmethod - def fromsympy(cls, expr): + def fromsympy(cls, expression): """ Create a linear expression from a SymPy expression. Raise TypeError is the sympy expression is not linear. @@ -417,7 +393,7 @@ class LinExpr: import sympy coefficients = [] constant = 0 - for symbol, coefficient in expr.as_coefficients_dict().items(): + for symbol, coefficient in expression.as_coefficients_dict().items(): coefficient = Fraction(coefficient.p, coefficient.q) if symbol == sympy.S.One: constant = coefficient @@ -429,23 +405,23 @@ class LinExpr: symbol = Symbol(symbol.name) coefficients.append((symbol, coefficient)) else: - raise TypeError('non-linear expression: {!r}'.format(expr)) - expr = LinExpr(coefficients, constant) - if not isinstance(expr, cls): + raise TypeError('non-linear expression: {!r}'.format(expression)) + expression = LinExpr(coefficients, constant) + if not isinstance(expression, cls): raise TypeError('cannot convert to a {} instance'.format(cls.__name__)) - return expr + return expression def tosympy(self): """ Convert the linear expression to a SymPy expression. """ import sympy - expr = 0 + expression = 0 for symbol, coefficient in self.coefficients(): term = coefficient * sympy.Symbol(symbol.name) - expr += term - expr += self.constant - return expr + expression += term + expression += self.constant + return expression class Symbol(LinExpr): @@ -525,9 +501,6 @@ class Symbol(LinExpr): def __repr__(self): return self.name - def _repr_latex_(self): - return '$${}$$'.format(self.name) - def symbols(names): """ @@ -586,9 +559,6 @@ class Dummy(Symbol): def __repr__(self): return '_{}'.format(self.name) - def _repr_latex_(self): - return '$${}_{{{}}}$$'.format(self.name, self._index) - class Rational(LinExpr, Fraction): """ @@ -633,13 +603,3 @@ class Rational(LinExpr, Fraction): 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)