def init(self, expr):
super(PatternObject, self).init(expr)
if self.arg_counts is not None:
if len(expr.leaves) not in self.arg_counts:
self.error_args(len(expr.leaves), *self.arg_counts)
self.expr = expr
self.head = Pattern.create(expr.head)
self.leaves = [Pattern.create(leaf) for leaf in expr.leaves]
def init(self, expr):
super(PatternObject, self).init(expr)
if self.arg_counts is not None:
if len(expr.leaves) not in self.arg_counts:
self.error_args(len(expr.leaves), *self.arg_counts)
self.expr = expr
self.head = Pattern.create(expr.head)
self.leaves = [Pattern.create(leaf) for leaf in expr.leaves]
def apply(self, expr, patterns, f, evaluation):
'Reap[expr_, {patterns___}, f_]'
patterns = patterns.get_sequence()
sown = [(Pattern.create(pattern), []) for pattern in patterns]
def listener(e, tag):
result = False
for pattern, items in sown:
if pattern.does_match(tag, evaluation):
for item in items:
if item[0].same(tag):
item[1].append(e)
break
else:
items.append((tag, [e]))
result = True
return result
evaluation.add_listener('sow', listener)
try:
result = expr.evaluate(evaluation)
items = []
for pattern, tags in sown:
list = Expression('List')
for tag, elements in tags:
list.leaves.append(
Expression(f, tag, Expression('List', *elements)))
items.append(list)
return Expression('List', result, Expression('List', *items))
finally:
evaluation.remove_listener('sow', listener)
def apply(self, expr, pattern, test, evaluation):
'ArrayQ[expr_, pattern_, test_]'
pattern = Pattern.create(pattern)
dims = [len(expr.get_leaves())] # to ensure an atom is not an array
def check(level, expr):
if not expr.has_form('List', None):
test_expr = Expression(test, expr)
if test_expr.evaluate(evaluation) != Symbol('True'):
return False
level_dim = None
else:
level_dim = len(expr.leaves)
if len(dims) > level:
if dims[level] != level_dim:
return False
else:
dims.append(level_dim)
if level_dim is not None:
for leaf in expr.leaves:
if not check(level + 1, leaf):
return False
return True
if not check(0, expr):
return Symbol('False')
depth = len(dims) - 1 # None doesn't count
if not pattern.does_match(Integer(depth), evaluation):
return Symbol('False')
return Symbol('True')
def apply(self, expr, patterns, f, evaluation):
'Reap[expr_, {patterns___}, f_]'
patterns = patterns.get_sequence()
sown = [(Pattern.create(pattern), []) for pattern in patterns]
def listener(e, tag):
result = False
for pattern, items in sown:
if pattern.does_match(tag, evaluation):
for item in items:
if item[0].same(tag):
item[1].append(e)
break
else:
items.append((tag, [e]))
result = True
return result
evaluation.add_listener('sow', listener)
try:
result = expr.evaluate(evaluation)
items = []
for pattern, tags in sown:
list = Expression('List')
for tag, elements in tags:
list.leaves.append(Expression(f, tag, Expression('List', *elements)))
items.append(list)
return Expression('List', result, Expression('List', *items))
finally:
evaluation.remove_listener('sow', listener)
def apply(self, f, x, evaluation):
'D[f_, x_?NotListQ]'
if f == x:
return Integer(1)
elif not f.is_atom() and len(f.leaves) == 1 and f.leaves[0] == x:
return Expression(
Expression(Expression('Derivative', Integer(1)), f.head), x)
elif not f.is_atom() and len(f.leaves) == 1:
g = f.leaves[0]
return Expression(
'Times', Expression('D', Expression(f.head, g), g),
Expression('D', g, x))
elif not f.is_atom() and len(f.leaves) > 1:
def summand(leaf, index):
if leaf.same(x):
result = Expression(Expression(
Expression(
'Derivative',
*([Integer(0)] * (index) + [Integer(1)] +
[Integer(0)] * (len(f.leaves) - index - 1))),
f.head), *f.leaves)
else:
result = Expression('D', f, leaf)
return Expression('Times', result, Expression('D', leaf, x))
x_pattern = Pattern.create(x)
result = Expression(
'Plus', *[
summand(leaf, index) for index, leaf in enumerate(f.leaves)
if not leaf.is_free(x_pattern, evaluation)])
if len(result.leaves) == 1:
return result.leaves[0]
else:
return result
def apply(self, expr, pattern, test, evaluation):
'ArrayQ[expr_, pattern_, test_]'
pattern = Pattern.create(pattern)
dims = [len(expr.get_leaves())] # to ensure an atom is not an array
def check(level, expr):
if not expr.has_form('List', None):
test_expr = Expression(test, expr)
if test_expr.evaluate(evaluation) != Symbol('True'):
return False
level_dim = None
else:
level_dim = len(expr.leaves)
if len(dims) > level:
if dims[level] != level_dim:
return False
else:
dims.append(level_dim)
if level_dim is not None:
for leaf in expr.leaves:
if not check(level + 1, leaf):
return False
return True
if not check(0, expr):
return Symbol('False')
depth = len(dims) - 1 # None doesn't count
if not pattern.does_match(Integer(depth), evaluation):
return Symbol('False')
return Symbol('True')
def apply(self, f, x, evaluation):
'D[f_, x_?NotListQ]'
if f == x:
return Integer(1)
elif not f.is_atom() and len(f.leaves) == 1 and f.leaves[0] == x:
return Expression(
Expression(Expression('Derivative', Integer(1)), f.head), x)
elif not f.is_atom() and len(f.leaves) == 1:
g = f.leaves[0]
return Expression(
'Times', Expression('D', Expression(f.head, g), g),
Expression('D', g, x))
elif not f.is_atom() and len(f.leaves) > 1:
def summand(leaf, index):
if leaf.same(x):
result = Expression(Expression(
Expression(
'Derivative',
*([Integer(0)] * (index) + [Integer(1)] +
[Integer(0)] * (len(f.leaves) - index - 1))),
f.head), *f.leaves)
else:
result = Expression('D', f, leaf)
return Expression('Times', result, Expression('D', leaf, x))
x_pattern = Pattern.create(x)
result = Expression(
'Plus', *[
summand(leaf, index) for index, leaf in enumerate(f.leaves)
if not leaf.is_free(x_pattern, evaluation)])
if len(result.leaves) == 1:
return result.leaves[0]
else:
return result
def apply(self, expr, form, evaluation):
"FreeQ[expr_, form_]"
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol("True")
else:
return Symbol("False")
def apply(self, expr, form, evaluation):
"FreeQ[expr_, form_]"
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol("True")
else:
return Symbol("False")
def apply(self, expr, form, evaluation):
'FreeQ[expr_, form_]'
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol('True')
else:
return Symbol('False')
def apply(self, expr, form, evaluation):
'FreeQ[expr_, form_]'
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol('True')
else:
return Symbol('False')
def apply(self, expr, form, evaluation):
'FreeQ[expr_, form_]'
"""def is_free(sub):
for vars, rest in form.match(sub, {}, evaluation, fully=False):
return False
if sub.is_atom():
return True
else:
return is_free(sub.head) and all(is_free(leaf) for leaf in sub.leaves)"""
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol('True')
else:
return Symbol('False')
def apply(self, expr, form, evaluation):
'FreeQ[expr_, form_]'
"""def is_free(sub):
for vars, rest in form.match(sub, {}, evaluation, fully=False):
return False
if sub.is_atom():
return True
else:
return is_free(sub.head) and all(is_free(leaf) for leaf in sub.leaves)"""
form = Pattern.create(form)
if expr.is_free(form, evaluation):
return Symbol('True')
else:
return Symbol('False')
def apply(self, eqs, vars, evaluation):
'Solve[eqs_, vars_]'
vars_original = vars
head_name = vars.get_head_name()
if head_name == 'System`List':
vars = vars.leaves
else:
vars = [vars]
for var in vars:
if ((var.is_atom() and not var.is_symbol()) or # noqa
head_name in ('System`Plus', 'System`Times', 'System`Power') or
'System`Constant' in var.get_attributes(evaluation.definitions)):
evaluation.message('Solve', 'ivar', vars_original)
return
eqs_original = eqs
if eqs.get_head_name() in ('System`List', 'System`And'):
eqs = eqs.leaves
else:
eqs = [eqs]
sympy_eqs = []
sympy_denoms = []
for eq in eqs:
symbol_name = eq.get_name()
if symbol_name == 'System`True':
pass
elif symbol_name == 'System`False':
return Expression('List')
elif not eq.has_form('Equal', 2):
return evaluation.message('Solve', 'eqf', eqs_original)
else:
left, right = eq.leaves
left = left.to_sympy()
right = right.to_sympy()
if left is None or right is None:
return
eq = left - right
eq = sympy.together(eq)
eq = sympy.cancel(eq)
sympy_eqs.append(eq)
numer, denom = eq.as_numer_denom()
sympy_denoms.append(denom)
vars_sympy = [var.to_sympy() for var in vars]
if None in vars_sympy:
return
# delete unused variables to avoid SymPy's
# PolynomialError: Not a zero-dimensional system
# in e.g. Solve[x^2==1&&z^2==-1,{x,y,z}]
all_vars = vars[:]
all_vars_sympy = vars_sympy[:]
vars = []
vars_sympy = []
for var, var_sympy in zip(all_vars, all_vars_sympy):
pattern = Pattern.create(var)
if not eqs_original.is_free(pattern, evaluation):
vars.append(var)
vars_sympy.append(var_sympy)
def transform_dict(sols):
if not sols:
yield sols
for var, sol in six.iteritems(sols):
rest = sols.copy()
del rest[var]
rest = transform_dict(rest)
if not isinstance(sol, (tuple, list)):
sol = [sol]
if not sol:
for r in rest:
yield r
else:
for r in rest:
for item in sol:
new_sols = r.copy()
new_sols[var] = item
yield new_sols
break
def transform_solution(sol):
if not isinstance(sol, dict):
if not isinstance(sol, (list, tuple)):
sol = [sol]
sol = dict(list(zip(vars_sympy, sol)))
return transform_dict(sol)
if not sympy_eqs:
sympy_eqs = True
elif len(sympy_eqs) == 1:
sympy_eqs = sympy_eqs[0]
try:
if isinstance(sympy_eqs, bool):
result = sympy_eqs
else:
result = sympy.solve(sympy_eqs, vars_sympy)
if not isinstance(result, list):
result = [result]
if (isinstance(result, list) and len(result) == 1 and
result[0] is True):
return Expression('List', Expression('List'))
if result == [None]:
return Expression('List')
results = []
for sol in result:
results.extend(transform_solution(sol))
result = results
if any(sol and any(var not in sol for var in all_vars_sympy)
for sol in result):
evaluation.message('Solve', 'svars')
# Filter out results for which denominator is 0
# (SymPy should actually do that itself, but it doesn't!)
result = [sol for sol in result if all(
sympy.simplify(denom.subs(sol)) != 0 for denom in sympy_denoms)]
return Expression('List', *(Expression(
'List',
*(Expression('Rule', var, from_sympy(sol[var_sympy]))
for var, var_sympy in zip(vars, vars_sympy)
if var_sympy in sol)
) for sol in result))
except sympy.PolynomialError:
# raised for e.g. Solve[x^2==1&&z^2==-1,{x,y,z}] when not deleting
# unused variables beforehand
pass
except NotImplementedError:
pass
except TypeError as exc:
if str(exc).startswith("expected Symbol, Function or Derivative"):
evaluation.message('Solve', 'ivar', vars_original)
def apply(self, f, x, evaluation):
"D[f_, x_?NotListQ]"
x_pattern = Pattern.create(x)
if f.is_free(x_pattern, evaluation):
return IntegerZero
elif f == x:
return Integer1
elif f.is_atom(): # Shouldn't happen
1 / 0
return
# So, this is not an atom...
head = f.get_head()
if head == SymbolPlus:
terms = [
Expression("D", term, x) for term in f.leaves
if not term.is_free(x_pattern, evaluation)
]
if len(terms) == 0:
return IntegerZero
return Expression(SymbolPlus, *terms)
elif head == SymbolTimes:
terms = []
for i, factor in enumerate(f.leaves):
if factor.is_free(x_pattern, evaluation):
continue
factors = [leaf for j, leaf in enumerate(f.leaves) if j != i]
factors.append(Expression("D", factor, x))
terms.append(Expression(SymbolTimes, *factors))
if len(terms) != 0:
return Expression(SymbolPlus, *terms)
else:
return IntegerZero
elif head == SymbolPower and len(f.leaves) == 2:
base, exp = f.leaves
terms = []
if not base.is_free(x_pattern, evaluation):
terms.append(
Expression(
SymbolTimes,
exp,
Expression(
SymbolPower,
base,
Expression(SymbolPlus, exp, IntegerMinusOne),
),
Expression("D", base, x),
))
if not exp.is_free(x_pattern, evaluation):
if base.is_atom() and base.get_name() == "System`E":
terms.append(
Expression(SymbolTimes, f, Expression("D", exp, x)))
else:
terms.append(
Expression(
SymbolTimes,
f,
Expression("Log", base),
Expression("D", exp, x),
))
if len(terms) == 0:
return IntegerZero
elif len(terms) == 1:
return terms[0]
else:
return Expression(SymbolPlus, *terms)
elif len(f.leaves) == 1:
if f.leaves[0] == x:
return Expression(
Expression(Expression("Derivative", Integer(1)), f.head),
x)
else:
g = f.leaves[0]
return Expression(
SymbolTimes,
Expression("D", Expression(f.head, g), g),
Expression("D", g, x),
)
else: # many leaves
def summand(leaf, index):
result = Expression(
Expression(
Expression(
"Derivative",
*([IntegerZero] * (index) + [Integer1] +
[IntegerZero] * (len(f.leaves) - index - 1))),
f.head,
), *f.leaves)
if leaf.sameQ(x):
return result
else:
return Expression("Times", result,
Expression("D", leaf, x))
result = [
summand(leaf, index) for index, leaf in enumerate(f.leaves)
if not leaf.is_free(x_pattern, evaluation)
]
if len(result) == 1:
return result[0]
elif len(result) == 0:
return IntegerZero
else:
return Expression("Plus", *result)
def apply(self, f, xs, evaluation, options):
"Integrate[f_, xs__, OptionsPattern[]]"
self.patpow0 = Pattern.create(
Expression("Power", Integer0, Expression("Blank")))
assuming = options["System`Assumptions"].evaluate(evaluation)
f_sympy = f.to_sympy()
if f_sympy is None or isinstance(f_sympy, SympyExpression):
return
xs = xs.get_sequence()
vars = []
prec = None
for x in xs:
if x.has_form("List", 3):
x, a, b = x.leaves
prec_a = a.get_precision()
prec_b = b.get_precision()
if prec_a is not None and prec_b is not None:
prec_new = min(prec_a, prec_b)
if prec is None or prec_new < prec:
prec = prec_new
a = a.to_sympy()
b = b.to_sympy()
if a is None or b is None:
return
else:
a = b = None
if not x.get_name():
evaluation.message("Integrate", "ilim")
return
x = x.to_sympy()
if x is None:
return
if a is None or b is None:
vars.append(x)
else:
vars.append((x, a, b))
try:
result = sympy.integrate(f_sympy, *vars)
except sympy.PolynomialError:
return
except ValueError:
# e.g. ValueError: can't raise polynomial to a negative power
return
except NotImplementedError:
# e.g. NotImplementedError: Result depends on the sign of
# -sign(_Mathics_User_j)*sign(_Mathics_User_w)
return
if prec is not None and isinstance(result, sympy.Integral):
# TODO MaxExtaPrecision -> maxn
result = result.evalf(dps(prec))
else:
result = from_sympy(result)
# If the result is defined as a Piecewise expression,
# use ConditionalExpression.
# This does not work now because the form sympy returns the values
if result.get_head_name() == "System`Piecewise":
cases = result._leaves[0]._leaves
if len(result._leaves) == 1:
if cases[-1]._leaves[1].is_true():
default = cases[-1]._leaves[0]
cases = result._leaves[0]._leaves[:-1]
else:
default = SymbolUndefined
else:
cases = result._leaves[0]._leaves
default = result._leaves[1]
if default.has_form("Integrate", None):
if default._leaves[0] == f:
default = SymbolUndefined
simplified_cases = []
for case in cases:
# TODO: if something like 0^n or 1/expr appears,
# put the condition n!=0 or expr!=0 accordingly in the list of
# conditions...
cond = Expression("Simplify", case._leaves[1],
assuming).evaluate(evaluation)
resif = Expression("Simplify", case._leaves[0],
assuming).evaluate(evaluation)
if cond.is_true():
return resif
if resif.has_form("ConditionalExpression", 2):
cond = Expression("And", resif._leaves[1], cond)
cond = Expression("Simplify", cond,
assuming).evaluate(evaluation)
resif = resif._leaves[0]
simplified_cases.append(Expression(SymbolList, resif, cond))
cases = simplified_cases
if default == SymbolUndefined and len(cases) == 1:
cases = cases[0]
result = Expression("ConditionalExpression", *(cases._leaves))
else:
result = Expression(result._head, cases, default)
else:
result = Expression("Simplify", result,
assuming).evaluate(evaluation)
return result
def apply(self, eqs, vars, evaluation):
'Solve[eqs_, vars_]'
vars_original = vars
head_name = vars.get_head_name()
if head_name == 'List':
vars = vars.leaves
else:
vars = [vars]
for var in vars:
if (var.is_atom()
and not var.is_symbol()) or head_name in ('Plus', 'Times',
'Power'):
evaluation.message('Solve', 'ivar', vars_original)
return
eqs_original = eqs
if eqs.get_head_name() in ('List', 'And'):
eqs = eqs.leaves
else:
eqs = [eqs]
sympy_eqs = []
sympy_denoms = []
for eq in eqs:
symbol_name = eq.get_name()
if symbol_name == 'True':
#return Expression('List', Expression('List'))
pass
elif symbol_name == 'False':
return Expression('List')
elif not eq.has_form('Equal', 2):
return evaluation.message('Solve', 'eqf', eqs_original)
else:
left, right = eq.leaves
left = left.to_sympy()
right = right.to_sympy()
#vars_sympy = [var.to_sympy() for var in vars]
eq = left - right
eq = sympy.together(eq)
eq = sympy.cancel(eq)
sympy_eqs.append(eq)
numer, denom = eq.as_numer_denom()
sympy_denoms.append(denom)
#eqs = actual_eqs
#left, right = eq.leaves
vars_sympy = [var.to_sympy() for var in vars]
# delete unused variables to avoid SymPy's
# PolynomialError: Not a zero-dimensional system
# in e.g. Solve[x^2==1&&z^2==-1,{x,y,z}]
all_vars = vars[:]
all_vars_sympy = vars_sympy[:]
#for index, var in enumerate(all_vars):
# if eqs_original.is_free(var, evaluation):
vars = []
vars_sympy = []
for var, var_sympy in zip(all_vars, all_vars_sympy):
pattern = Pattern.create(var)
if not eqs_original.is_free(pattern, evaluation):
vars.append(var)
vars_sympy.append(var_sympy)
def transform_dict(sols):
#print "Transform %s" % sols
if not sols:
yield sols
for var, sol in sols.iteritems():
rest = sols.copy()
del rest[var]
rest = transform_dict(rest)
if not isinstance(sol, (tuple, list)):
#print "Convert %s (type %s)" % (sol, type(sol))
sol = [sol]
if not sol:
for r in rest:
#print "Yield %s" % r
yield r
else:
for r in rest:
for item in sol:
#print "Yield %s with new %s" % (r, item)
new_sols = r.copy()
new_sols[var] = item
yield new_sols
break
def transform_solution(sol):
#if isinstance(sol, (list, tuple)):
if not isinstance(sol, dict):
if not isinstance(sol, (list, tuple)):
sol = [sol]
sol = dict(zip(vars_sympy, sol))
#return sol
return transform_dict(sol)
if not sympy_eqs:
sympy_eqs = True
elif len(sympy_eqs) == 1:
sympy_eqs = sympy_eqs[0]
#eq = left - right
#eq = sympy.together(eq)
#eq = sympy.cancel(eq) # otherwise Solve[f''[x]==0,x] for f[x_]:=4 x / (x ^ 2 + 3 x + 5) takes forever
try:
#print sympy_eqs
result = sympy.solve(sympy_eqs, vars_sympy)
#print result
if not isinstance(result, list):
result = [result]
if result == [True]:
return Expression('List', Expression('List'))
if result == [None]:
return Expression('List')
#print result
#result = [transform_solution(sol) for sol in result]
results = []
for sol in result:
results.extend(transform_solution(sol))
result = results
#print result
if any(sol and any(var not in sol for var in all_vars_sympy)
for sol in result):
evaluation.message('Solve', 'svars')
#numer, denom = eq.as_numer_denom()
#for sol in result:
# sol_denom = denom.subs({var_sympy: sol})
result = [
sol for sol in result if all(
sympy.simplify(denom.subs(sol)) != 0
for denom in sympy_denoms)
] # filter out results for which denominator is 0
# (SymPy should actually do that itself, but it doesn't!)
return Expression(
'List',
*(Expression(
'List',
*(Expression('Rule', var, from_sympy(sol[var_sympy]))
for var, var_sympy in zip(vars, vars_sympy)
if var_sympy in sol)) for sol in result))
#except TypeError:
#evaluation.message('Solve', 'ivar', vars_original)
#raise
except sympy.PolynomialError:
# raised for e.g. Solve[x^2==1&&z^2==-1,{x,y,z}] when not deleting unused variables beforehand
pass
except NotImplementedError:
pass
def apply(self, eqs, vars, evaluation):
'Solve[eqs_, vars_]'
vars_original = vars
head_name = vars.get_head_name()
if head_name == 'System`List':
vars = vars.leaves
else:
vars = [vars]
for var in vars:
if ((var.is_atom() and not var.is_symbol()) or # noqa
head_name in ('System`Plus', 'System`Times', 'System`Power') or
'System`Constant' in var.get_attributes(evaluation.definitions)):
evaluation.message('Solve', 'ivar', vars_original)
return
eqs_original = eqs
if eqs.get_head_name() in ('System`List', 'System`And'):
eqs = eqs.leaves
else:
eqs = [eqs]
sympy_eqs = []
sympy_denoms = []
for eq in eqs:
symbol_name = eq.get_name()
if symbol_name == 'System`True':
pass
elif symbol_name == 'System`False':
return Expression('List')
elif not eq.has_form('Equal', 2):
return evaluation.message('Solve', 'eqf', eqs_original)
else:
left, right = eq.leaves
left = left.to_sympy()
right = right.to_sympy()
eq = left - right
eq = sympy.together(eq)
eq = sympy.cancel(eq)
sympy_eqs.append(eq)
numer, denom = eq.as_numer_denom()
sympy_denoms.append(denom)
vars_sympy = [var.to_sympy() for var in vars]
# delete unused variables to avoid SymPy's
# PolynomialError: Not a zero-dimensional system
# in e.g. Solve[x^2==1&&z^2==-1,{x,y,z}]
all_vars = vars[:]
all_vars_sympy = vars_sympy[:]
vars = []
vars_sympy = []
for var, var_sympy in zip(all_vars, all_vars_sympy):
pattern = Pattern.create(var)
if not eqs_original.is_free(pattern, evaluation):
vars.append(var)
vars_sympy.append(var_sympy)
def transform_dict(sols):
if not sols:
yield sols
for var, sol in six.iteritems(sols):
rest = sols.copy()
del rest[var]
rest = transform_dict(rest)
if not isinstance(sol, (tuple, list)):
sol = [sol]
if not sol:
for r in rest:
yield r
else:
for r in rest:
for item in sol:
new_sols = r.copy()
new_sols[var] = item
yield new_sols
break
def transform_solution(sol):
if not isinstance(sol, dict):
if not isinstance(sol, (list, tuple)):
sol = [sol]
sol = dict(list(zip(vars_sympy, sol)))
return transform_dict(sol)
if not sympy_eqs:
sympy_eqs = True
elif len(sympy_eqs) == 1:
sympy_eqs = sympy_eqs[0]
try:
if isinstance(sympy_eqs, bool):
result = sympy_eqs
else:
result = sympy.solve(sympy_eqs, vars_sympy)
if not isinstance(result, list):
result = [result]
if (isinstance(result, list) and len(result) == 1 and
result[0] is True):
return Expression('List', Expression('List'))
if result == [None]:
return Expression('List')
results = []
for sol in result:
results.extend(transform_solution(sol))
result = results
if any(sol and any(var not in sol for var in all_vars_sympy)
for sol in result):
evaluation.message('Solve', 'svars')
# Filter out results for which denominator is 0
# (SymPy should actually do that itself, but it doesn't!)
result = [sol for sol in result if all(
sympy.simplify(denom.subs(sol)) != 0 for denom in sympy_denoms)]
return Expression('List', *(Expression(
'List',
*(Expression('Rule', var, from_sympy(sol[var_sympy]))
for var, var_sympy in zip(vars, vars_sympy)
if var_sympy in sol)
) for sol in result))
except sympy.PolynomialError:
# raised for e.g. Solve[x^2==1&&z^2==-1,{x,y,z}] when not deleting
# unused variables beforehand
pass
except NotImplementedError:
pass
except TypeError as exc:
if str(exc).startswith("expected Symbol, Function or Derivative"):
evaluation.message('Solve', 'ivar', vars_original)
def apply(self, eqs, vars, evaluation):
'Solve[eqs_, vars_]'
vars_original = vars
head_name = vars.get_head_name()
if head_name == 'List':
vars = vars.leaves
else:
vars = [vars]
for var in vars:
if (var.is_atom() and not var.is_symbol()) or head_name in ('Plus', 'Times', 'Power'):
evaluation.message('Solve', 'ivar', vars_original)
return
eqs_original = eqs
if eqs.get_head_name() in ('List', 'And'):
eqs = eqs.leaves
else:
eqs = [eqs]
sympy_eqs = []
sympy_denoms = []
for eq in eqs:
symbol_name = eq.get_name()
if symbol_name == 'True':
#return Expression('List', Expression('List'))
pass
elif symbol_name == 'False':
return Expression('List')
elif not eq.has_form('Equal', 2):
return evaluation.message('Solve', 'eqf', eqs_original)
else:
left, right = eq.leaves
left = left.to_sympy()
right = right.to_sympy()
#vars_sympy = [var.to_sympy() for var in vars]
eq = left - right
eq = sympy.together(eq)
eq = sympy.cancel(eq)
sympy_eqs.append(eq)
numer, denom = eq.as_numer_denom()
sympy_denoms.append(denom)
#eqs = actual_eqs
#left, right = eq.leaves
vars_sympy = [var.to_sympy() for var in vars]
# delete unused variables to avoid SymPy's
# PolynomialError: Not a zero-dimensional system
# in e.g. Solve[x^2==1&&z^2==-1,{x,y,z}]
all_vars = vars[:]
all_vars_sympy = vars_sympy[:]
#for index, var in enumerate(all_vars):
# if eqs_original.is_free(var, evaluation):
vars = []
vars_sympy = []
for var, var_sympy in zip(all_vars, all_vars_sympy):
pattern = Pattern.create(var)
if not eqs_original.is_free(pattern, evaluation):
vars.append(var)
vars_sympy.append(var_sympy)
def transform_dict(sols):
#print "Transform %s" % sols
if not sols:
yield sols
for var, sol in sols.iteritems():
rest = sols.copy()
del rest[var]
rest = transform_dict(rest)
if not isinstance(sol, (tuple, list)):
#print "Convert %s (type %s)" % (sol, type(sol))
sol = [sol]
if not sol:
for r in rest:
#print "Yield %s" % r
yield r
else:
for r in rest:
for item in sol:
#print "Yield %s with new %s" % (r, item)
new_sols = r.copy()
new_sols[var] = item
yield new_sols
break
def transform_solution(sol):
#if isinstance(sol, (list, tuple)):
if not isinstance(sol, dict):
if not isinstance(sol, (list, tuple)):
sol = [sol]
sol = dict(zip(vars_sympy, sol))
#return sol
return transform_dict(sol)
if not sympy_eqs:
sympy_eqs = True
elif len(sympy_eqs) == 1:
sympy_eqs = sympy_eqs[0]
#eq = left - right
#eq = sympy.together(eq)
#eq = sympy.cancel(eq) # otherwise Solve[f''[x]==0,x] for f[x_]:=4 x / (x ^ 2 + 3 x + 5) takes forever
try:
#print sympy_eqs
result = sympy.solve(sympy_eqs, vars_sympy)
#print result
if not isinstance(result, list):
result = [result]
if result == [True]:
return Expression('List', Expression('List'))
if result == [None]:
return Expression('List')
#print result
#result = [transform_solution(sol) for sol in result]
results = []
for sol in result:
results.extend(transform_solution(sol))
result = results
#print result
if any(sol and any(var not in sol for var in all_vars_sympy) for sol in result):
evaluation.message('Solve', 'svars')
#numer, denom = eq.as_numer_denom()
#for sol in result:
# sol_denom = denom.subs({var_sympy: sol})
result = [sol for sol in result if all(sympy.simplify(denom.subs(sol)) != 0 for denom in sympy_denoms)] # filter out results for which denominator is 0
# (SymPy should actually do that itself, but it doesn't!)
return Expression('List', *(Expression('List', *(Expression('Rule', var, from_sympy(sol[var_sympy]))
for var, var_sympy in zip(vars, vars_sympy) if var_sympy in sol)) for sol in result))
#except TypeError:
#evaluation.message('Solve', 'ivar', vars_original)
#raise
except sympy.PolynomialError:
# raised for e.g. Solve[x^2==1&&z^2==-1,{x,y,z}] when not deleting unused variables beforehand
pass
except NotImplementedError:
pass