def real(self, nested_scope=None):
"""Return the correspond floating point number."""
op = self.children[0].name
expr = self.children[1]
dispatch = {
'sin': sympy.sin,
'cos': sympy.cos,
'tan': sympy.tan,
'asin': sympy.asin,
'acos': sympy.acos,
'atan': sympy.atan,
'exp': sympy.exp,
'ln': sympy.log,
'sqrt': sympy.sqrt
}
if op in dispatch:
arg = expr.real(nested_scope)
return dispatch[op](arg)
else:
raise NodeException("internal error: undefined external")
python类acos()的实例源码
def sym(self, nested_scope=None):
"""Return the corresponding symbolic expression."""
op = self.children[0].name
expr = self.children[1]
dispatch = {
'sin': sympy.sin,
'cos': sympy.cos,
'tan': sympy.tan,
'asin': sympy.asin,
'acos': sympy.acos,
'atan': sympy.atan,
'exp': sympy.exp,
'ln': sympy.log,
'sqrt': sympy.sqrt
}
if op in dispatch:
arg = expr.sym(nested_scope)
return dispatch[op](arg)
else:
raise NodeException("internal error: undefined external")
def cartesian_to_spherical_sympy(X):
vacos = numpy.vectorize(sympy.acos)
return numpy.stack([
_atan2_0(X),
vacos(X[:, 2])
], axis=1)
def eval_trigsubstitution(theta, func, rewritten, substep, integrand, symbol):
func = func.subs(sympy.sec(theta), 1/sympy.cos(theta))
trig_function = list(func.find(TrigonometricFunction))
assert len(trig_function) == 1
trig_function = trig_function[0]
relation = sympy.solve(symbol - func, trig_function)
assert len(relation) == 1
numer, denom = sympy.fraction(relation[0])
if isinstance(trig_function, sympy.sin):
opposite = numer
hypotenuse = denom
adjacent = sympy.sqrt(denom**2 - numer**2)
inverse = sympy.asin(relation[0])
elif isinstance(trig_function, sympy.cos):
adjacent = numer
hypotenuse = denom
opposite = sympy.sqrt(denom**2 - numer**2)
inverse = sympy.acos(relation[0])
elif isinstance(trig_function, sympy.tan):
opposite = numer
adjacent = denom
hypotenuse = sympy.sqrt(denom**2 + numer**2)
inverse = sympy.atan(relation[0])
substitution = [
(sympy.sin(theta), opposite/hypotenuse),
(sympy.cos(theta), adjacent/hypotenuse),
(sympy.tan(theta), opposite/adjacent),
(theta, inverse)
]
return _manualintegrate(substep).subs(substitution).trigsimp()
def eval_trigsubstitution(theta, func, rewritten, substep, restriction, integrand, symbol):
func = func.subs(sympy.sec(theta), 1/sympy.cos(theta))
trig_function = list(func.find(TrigonometricFunction))
assert len(trig_function) == 1
trig_function = trig_function[0]
relation = sympy.solve(symbol - func, trig_function)
assert len(relation) == 1
numer, denom = sympy.fraction(relation[0])
if isinstance(trig_function, sympy.sin):
opposite = numer
hypotenuse = denom
adjacent = sympy.sqrt(denom**2 - numer**2)
inverse = sympy.asin(relation[0])
elif isinstance(trig_function, sympy.cos):
adjacent = numer
hypotenuse = denom
opposite = sympy.sqrt(denom**2 - numer**2)
inverse = sympy.acos(relation[0])
elif isinstance(trig_function, sympy.tan):
opposite = numer
adjacent = denom
hypotenuse = sympy.sqrt(denom**2 + numer**2)
inverse = sympy.atan(relation[0])
substitution = [
(sympy.sin(theta), opposite/hypotenuse),
(sympy.cos(theta), adjacent/hypotenuse),
(sympy.tan(theta), opposite/adjacent),
(theta, inverse)
]
return sympy.Piecewise(
(_manualintegrate(substep).subs(substitution).trigsimp(), restriction)
)
def test_angle_between():
a = Point(1, 2, 3, 4)
b = a.orthogonal_direction
o = a.origin
assert feq(Line.angle_between(Line(Point(0, 0), Point(1, 1)),
Line(Point(0, 0), Point(5, 0))).evalf(), pi.evalf() / 4)
assert Line(a, o).angle_between(Line(b, o)) == pi / 2
assert Line3D.angle_between(Line3D(Point3D(0, 0, 0), Point3D(1, 1, 1)),
Line3D(Point3D(0, 0, 0), Point3D(5, 0, 0))), acos(sqrt(3) / 3)
def find_substitutions(integrand, symbol, u_var):
results = []
def test_subterm(u, u_diff):
substituted = integrand / u_diff
if symbol not in substituted.free_symbols:
# replaced everything already
return False
substituted = substituted.subs(u, u_var).cancel()
if symbol not in substituted.free_symbols:
return substituted.as_independent(u_var, as_Add=False)
return False
def possible_subterms(term):
if isinstance(term, (TrigonometricFunction,
sympy.asin, sympy.acos, sympy.atan,
sympy.exp, sympy.log, sympy.Heaviside)):
return [term.args[0]]
elif isinstance(term, sympy.Mul):
r = []
for u in term.args:
r.append(u)
r.extend(possible_subterms(u))
return r
elif isinstance(term, sympy.Pow):
if term.args[1].is_constant(symbol):
return [term.args[0]]
elif term.args[0].is_constant(symbol):
return [term.args[1]]
elif isinstance(term, sympy.Add):
r = []
for arg in term.args:
r.append(arg)
r.extend(possible_subterms(arg))
return r
return []
for u in possible_subterms(integrand):
if u == symbol:
continue
u_diff = manual_diff(u, symbol)
new_integrand = test_subterm(u, u_diff)
if new_integrand is not False:
constant, new_integrand = new_integrand
substitution = (u, constant, new_integrand)
if substitution not in results:
results.append(substitution)
return results
def _parts_rule(integrand, symbol):
# LIATE rule:
# log, inverse trig, algebraic (polynomial), trigonometric, exponential
def pull_out_polys(integrand):
integrand = integrand.together()
polys = [arg for arg in integrand.args if arg.is_polynomial(symbol)]
if polys:
u = sympy.Mul(*polys)
dv = integrand / u
return u, dv
def pull_out_u(*functions):
def pull_out_u_rl(integrand):
if any([integrand.has(f) for f in functions]):
args = [arg for arg in integrand.args
if any(isinstance(arg, cls) for cls in functions)]
if args:
u = reduce(lambda a,b: a*b, args)
dv = integrand / u
return u, dv
return pull_out_u_rl
liate_rules = [pull_out_u(sympy.log), pull_out_u(sympy.atan, sympy.asin, sympy.acos),
pull_out_polys, pull_out_u(sympy.sin, sympy.cos),
pull_out_u(sympy.exp)]
dummy = sympy.Dummy("temporary")
# we can integrate log(x) and atan(x) by setting dv = 1
if isinstance(integrand, (sympy.log, sympy.atan, sympy.asin, sympy.acos)):
integrand = dummy * integrand
for index, rule in enumerate(liate_rules):
result = rule(integrand)
if result:
u, dv = result
# Don't pick u to be a constant if possible
if symbol not in u.free_symbols and not u.has(dummy):
return
u = u.subs(dummy, 1)
dv = dv.subs(dummy, 1)
for rule in liate_rules[index + 1:]:
r = rule(integrand)
# make sure dv is amenable to integration
if r and r[0].subs(dummy, 1) == dv:
du = u.diff(symbol)
v_step = integral_steps(dv, symbol)
v = _manualintegrate(v_step)
return u, dv, v, du, v_step
def find_substitutions(integrand, symbol, u_var):
results = []
def test_subterm(u, u_diff):
substituted = integrand / u_diff
if symbol not in substituted.free_symbols:
# replaced everything already
return False
substituted = substituted.subs(u, u_var).cancel()
if symbol not in substituted.free_symbols:
return substituted.as_independent(u_var, as_Add=False)
return False
def possible_subterms(term):
if isinstance(term, (TrigonometricFunction,
sympy.asin, sympy.acos, sympy.atan,
sympy.exp, sympy.log, sympy.Heaviside)):
return [term.args[0]]
elif isinstance(term, sympy.Mul):
r = []
for u in term.args:
r.append(u)
r.extend(possible_subterms(u))
return r
elif isinstance(term, sympy.Pow):
if term.args[1].is_constant(symbol):
return [term.args[0]]
elif term.args[0].is_constant(symbol):
return [term.args[1]]
elif isinstance(term, sympy.Add):
r = []
for arg in term.args:
r.append(arg)
r.extend(possible_subterms(arg))
return r
return []
for u in possible_subterms(integrand):
if u == symbol:
continue
u_diff = manual_diff(u, symbol)
new_integrand = test_subterm(u, u_diff)
if new_integrand is not False:
constant, new_integrand = new_integrand
if new_integrand == integrand.subs(symbol, u_var):
continue
substitution = (u, constant, new_integrand)
if substitution not in results:
results.append(substitution)
return results
def _parts_rule(integrand, symbol):
# LIATE rule:
# log, inverse trig, algebraic, trigonometric, exponential
def pull_out_algebraic(integrand):
integrand = integrand.cancel().together()
algebraic = [arg for arg in integrand.args if arg.is_algebraic_expr(symbol)]
if algebraic:
u = sympy.Mul(*algebraic)
dv = (integrand / u).cancel()
if not u.is_polynomial() and isinstance(dv, sympy.exp):
return
return u, dv
def pull_out_u(*functions):
def pull_out_u_rl(integrand):
if any([integrand.has(f) for f in functions]):
args = [arg for arg in integrand.args
if any(isinstance(arg, cls) for cls in functions)]
if args:
u = reduce(lambda a,b: a*b, args)
dv = integrand / u
return u, dv
return pull_out_u_rl
liate_rules = [pull_out_u(sympy.log), pull_out_u(sympy.atan, sympy.asin, sympy.acos),
pull_out_algebraic, pull_out_u(sympy.sin, sympy.cos),
pull_out_u(sympy.exp)]
dummy = sympy.Dummy("temporary")
# we can integrate log(x) and atan(x) by setting dv = 1
if isinstance(integrand, (sympy.log, sympy.atan, sympy.asin, sympy.acos)):
integrand = dummy * integrand
for index, rule in enumerate(liate_rules):
result = rule(integrand)
if result:
u, dv = result
# Don't pick u to be a constant if possible
if symbol not in u.free_symbols and not u.has(dummy):
return
u = u.subs(dummy, 1)
dv = dv.subs(dummy, 1)
for rule in liate_rules[index + 1:]:
r = rule(integrand)
# make sure dv is amenable to integration
if r and sympy.simplify(r[0].subs(dummy, 1)) == sympy.simplify(dv):
du = u.diff(symbol)
v_step = integral_steps(sympy.simplify(dv), symbol)
v = _manualintegrate(v_step)
return u, dv, v, du, v_step
