def _remove_subtractions(exp):
a,b = core.wilds('a b')
vals = {}
if exp.match(stdops.Sub(a,b), vals):
return vals['a'] + (-vals['b'])
else:
return exp
def _get_factors(exp):
rv = {}
a, b = core.wilds('a b')
vals = {}
if exp.match(a * b, vals):
tmp = _get_factors(vals['a'])
for i in tmp:
if i in rv:
rv[i] += tmp[i]
else:
rv[i] = tmp[i]
tmp = _get_factors(vals['b'])
for i in tmp:
if i in rv:
rv[i] += tmp[i]
else:
rv[i] = tmp[i]
elif exp.match(a**b, vals):
rv = _get_factors(vals['a'])
for k in rv:
rv[k] = rv[k] * vals['b']
else:
rv[exp] = 1
return rv
def _remove_subtractions(exp):
a, b = core.wilds('a b')
vals = {}
if exp.match(stdops.Sub(a, b), vals):
return vals['a'] + (-vals['b'])
else:
return exp
def _diff_known_function(expression, variable):
vals = WildResults()
g,h = wilds('g h')
if expression[0] not in _known_functions:
raise DifferentiationError("d/d%s %s" % (variable,expression))
if expression.match(g + h, vals):
return diff(vals.g, variable) + diff(vals.h, variable)
elif expression.match(g - h, vals):
return diff(vals.g, variable) - diff(vals.h, variable)
elif expression.match(variable ** g, vals):
return vals.g * (variable ** (vals.g - 1))
elif expression.match(g * h, vals):
return vals.g * diff(vals.h, variable) + vals.h * diff(vals.g, variable)
elif expression.match(g / h, vals):
return (diff(vals.g, variable) * vals.h - vals.g * diff(vals.h, variable)) / (vals.h ** 2)
elif expression.match(Exp(variable)):
return expression
elif expression.match(Sin(variable)):
return Sin(variable)
elif expression.match(Cos(variable)):
return -1 * Sin(variable)
raise DifferentiationError("d/d%s %s" % (variable,expression))
def _get_factors(exp):
rv = {}
a,b = core.wilds('a b')
vals = {}
if exp.match(a * b, vals):
tmp = _get_factors(vals['a'])
for i in tmp:
if i in rv:
rv[i] += tmp[i]
else:
rv[i] = tmp[i]
tmp = _get_factors(vals['b'])
for i in tmp:
if i in rv:
rv[i] += tmp[i]
else:
rv[i] = tmp[i]
elif exp.match(a ** b, vals):
rv = _get_factors(vals['a'])
for k in rv:
rv[k] = rv[k] * vals['b']
else:
rv[exp] = 1
return rv
def _(exp):
a, b, c = core.wilds('a b c')
vals = {}
if exp.match(op1(op2(a, b), c), vals):
return op2(op1(vals['c'], vals['a']), op1(vals['c'], vals['b']))
elif exp.match(op1(a, op2(b, c)), vals):
return op2(op1(vals['a'], vals['b']), op1(vals['a'], vals['c']))
else:
return exp
def _(exp):
a,b,c = core.wilds('a b c')
vals = {}
if exp.match(op1(op2(a, b), c), vals):
return op2(op1(vals['c'], vals['a']), op1(vals['c'], vals['b']))
elif exp.match(op1(a, op2(b, c)), vals):
return op2(op1(vals['a'], vals['b']), op1(vals['a'], vals['c']))
else:
return exp
def _fold_additions(exp):
a, b, c = core.wilds('a b c')
vals = {}
if exp.match(a + a, vals):
return vals['a'] * 2
elif exp.match(a + (a * b), vals) or exp.match(a + (b * a), vals):
return (vals['b'] + 1) * vals['a']
else:
return exp
def _simplify_known_values(exp):
a,b,c = core.wilds('a b c')
vals = {}
if exp.match(a(b,c), vals) \
and 'numeric' in vals['a'].kargs \
and isinstance(vals['b'], core._KnownValue) \
and isinstance(vals['c'], core._KnownValue):
cast = vals['a'].kargs['cast'] if 'cast' in vals['a'].kargs else (lambda x: x)
nfn = getattr(operator, vals['a'].kargs['numeric'])
return core.symbolic(nfn(cast(vals['b'].value()), cast(vals['c'].value())))
else:
return exp
def _fold_additions(exp):
a,b,c = core.wilds('a b c')
vals = {}
if exp.match(a + a, vals):
return vals['a'] * 2
elif exp.match(a + (a * b), vals) or exp.match(a + (b * a), vals):
return (vals['b'] + 1) * vals['a']
else:
return exp
def _simplify_known_values(exp):
a, b, c = core.wilds('a b c')
vals = {}
if exp.match(a(b,c), vals) \
and 'numeric' in vals['a'].kargs \
and isinstance(vals['b'], core._KnownValue) \
and isinstance(vals['c'], core._KnownValue):
cast = vals['a'].kargs['cast'] if 'cast' in vals['a'].kargs else (
lambda x: x)
nfn = getattr(operator, vals['a'].kargs['numeric'])
return core.symbolic(
nfn(cast(vals['b'].value()), cast(vals['c'].value())))
else:
return exp
def _simplify_bitops(exp):
a,b = core.wilds('a b')
vals = core.WildResults()
if exp.match(a ^ a):
return core.symbolic(0)
elif exp.match(a | a, vals):
return vals.a
elif exp.match(a & a, vals):
return vals.a
elif exp.match((a << b) >> b, vals) or exp.match((a >> b) << b, vals):
return vals.a
else:
return exp
def _convert_to_pow(exp):
a,b,c = core.wilds('a b c')
if not exp.match(a(b,c)):
return exp
fs = _get_factors(exp)
rv = 1
for k in fs:
if fs[k] == 1:
rv = rv * k
else:
rv = rv * (k ** fs[k])
return rv
def _convert_to_pow(exp):
a, b, c = core.wilds('a b c')
if not exp.match(a(b, c)):
return exp
fs = _get_factors(exp)
rv = 1
for k in fs:
if fs[k] == 1:
rv = rv * k
else:
rv = rv * (k**fs[k])
return rv
def _simplify_bitops(exp):
a, b = core.wilds('a b')
vals = core.WildResults()
if exp.match(a ^ a):
return core.symbolic(0)
elif exp.match(a | a, vals):
return vals.a
elif exp.match(a & a, vals):
return vals.a
elif exp.match((a << b) >> b, vals) or exp.match((a >> b) << b, vals):
return vals.a
else:
return exp
def _strip_identities_pass(exp):
a,b,c = core.wilds('a b c')
vals = {}
if exp.match(a(b, c)):
kargs = exp[0].kargs
lidentity = kargs['lidentity'] if 'lidentity' in kargs else kargs['identity'] if 'identity' in kargs else None
ridentity = kargs['ridentity'] if 'ridentity' in kargs else kargs['identity'] if 'identity' in kargs else None
if lidentity != None and exp.match(a(lidentity, b), vals):
return vals['b'].walk(_strip_identities)
elif ridentity != None and exp.match(a(b, ridentity), vals):
return vals['b'].walk(_strip_identities)
return exp
def _simplify_mul_div(exp):
a, b, c = core.wilds('a b c')
vals = core.WildResults()
if exp.match(c * (b / c), vals) or exp.match((b / c) * c, vals):
return vals.b
if exp.match(a * (b / c), vals) or exp.match((b / c) * a, vals):
return (vals.a * vals.b) / vals.c
elif exp.match(a / b, vals) and isinstance(vals.b, core.Number):
return vals.a * (1.0 / vals.b.value())
elif exp.match(a / b, vals) and factor.is_factor(vals.b, vals.a):
return factor.get_coefficient(vals.a, vals.b)
return exp
def _simplify_mul_div(exp):
a,b,c = core.wilds('a b c')
vals = core.WildResults()
if exp.match(c * (b / c), vals) or exp.match((b / c) * c, vals):
return vals.b
if exp.match(a * (b / c), vals) or exp.match((b / c) * a, vals):
return (vals.a * vals.b) / vals.c
elif exp.match(a / b, vals) and isinstance(vals.b, core.Number):
return vals.a * (1.0 / vals.b.value())
elif exp.match(a / b, vals) and factor.is_factor(vals.b, vals.a):
return factor.get_coefficient(vals.a, vals.b)
return exp
def _strip_identities_pass(exp):
a, b, c = core.wilds('a b c')
vals = {}
if exp.match(a(b, c)):
kargs = exp[0].kargs
lidentity = kargs['lidentity'] if 'lidentity' in kargs else kargs[
'identity'] if 'identity' in kargs else None
ridentity = kargs['ridentity'] if 'ridentity' in kargs else kargs[
'identity'] if 'identity' in kargs else None
if lidentity != None and exp.match(a(lidentity, b), vals):
return vals['b'].walk(_strip_identities)
elif ridentity != None and exp.match(a(b, ridentity), vals):
return vals['b'].walk(_strip_identities)
return exp
def _diff_known_function(expression, variable):
vals = WildResults()
g,h = wilds('g h')
if expression[0] not in _known_functions:
raise DifferentiationError("d/d%s %s" % (variable,expression))
if expression.match(g + h, vals):
return diff(vals.g, variable) + diff(vals.h, variable)
elif expression.match(g - h, vals):
return diff(vals.g, variable) - diff(vals.h, variable)
elif expression.match(variable ** g, vals):
return vals.g * (variable ** (vals.g - 1))
elif expression.match(g * h, vals):
return vals.g * diff(vals.h, variable) + vals.h * diff(vals.g, variable)
elif expression.match(g / h, vals):
return (diff(vals.g, variable) * vals.h - vals.g * diff(vals.h, variable)) / (vals.h ** 2)
elif expression.match(Exp(variable)):
return expression
elif expression.match(Sin(variable)):
return Sin(variable)
elif expression.match(Cos(variable)):
return -1 * Sin(variable)
elif expression.match(Sum(g, h), vals):
if(variable(vals.g) in vals.h):
return Sum(vals.g, diff(vals.h, variable(vals.g)))
else:
return Sum(vals.g, diff(vals.h, variable))
elif expression.match(Log(variable), vals):
return 1.0 / variable
raise DifferentiationError("d/d%s %s" % (variable,expression))
def diff(expression, variable):
vals = WildResults()
f,a,b = wilds('f a b')
expression = expression.simplify()
if variable not in expression:
return symbolic(0)
elif expression.match(variable):
return symbolic(1)
elif expression.match(f(a,b), vals) and vals.f in _known_functions:
return _diff_known_function(expression, variable)
elif expression.match(f(a), vals) and vals.f in _known_functions:
return _diff_known_function(vals.f(vals.a), vals.a) * diff(vals.a, variable)
raise DifferentiationError("d/d%s %s" % (variable,expression))
def diff(expression, variable):
vals = WildResults()
f,a,b = wilds('f a b')
expression = expression.simplify()
if variable not in expression:
return symbolic(0)
elif expression.match(variable):
return symbolic(1)
elif expression.match(f(a,b), vals) and vals.f in _known_functions:
return _diff_known_function(expression, variable)
elif expression.match(f(a), vals) and vals.f in _known_functions:
return _diff_known_function(vals.f(vals.a), vals.a) * diff(vals.a, variable)
raise DifferentiationError("d/d%s %s" % (variable,expression))
