def directional_derivative(field):
field = express(field, other.system, variables=True)
out = self.dot(other._i) * df(field, other._x)
out += self.dot(other._j) * df(field, other._y)
out += self.dot(other._k) * df(field, other._z)
if out == 0 and isinstance(field, Vector):
out = Vector.zero
return out
def directional_derivative(field):
field = express(field, other.system, variables = True)
out = self.dot(other._i) * df(field, other._x)
out += self.dot(other._j) * df(field, other._y)
out += self.dot(other._k) * df(field, other._z)
if out == 0 and isinstance(field, Vector):
out = Vector.zero
return out
def directional_derivative(field):
from sympy.vector.operators import _get_coord_sys_from_expr
coord_sys = _get_coord_sys_from_expr(field)
if coord_sys is not None:
field = express(field, coord_sys, variables=True)
out = self.dot(coord_sys._i) * df(field, coord_sys._x)
out += self.dot(coord_sys._j) * df(field, coord_sys._y)
out += self.dot(coord_sys._k) * df(field, coord_sys._z)
if out == 0 and isinstance(field, Vector):
out = Vector.zero
return out
elif isinstance(field, Vector):
return Vector.zero
else:
return S(0)
def directional_derivative(field):
from sympy.vector.operators import _get_coord_sys_from_expr
coord_sys = _get_coord_sys_from_expr(field)
if coord_sys is not None:
field = express(field, coord_sys, variables=True)
out = self.dot(coord_sys._i) * df(field, coord_sys._x)
out += self.dot(coord_sys._j) * df(field, coord_sys._y)
out += self.dot(coord_sys._k) * df(field, coord_sys._z)
if out == 0 and isinstance(field, Vector):
out = Vector.zero
return out
elif isinstance(field, Vector) :
return Vector.zero
else:
return S(0)
def diff(self, *args, **kwargs):
"""
Implements the SymPy diff routine, for vectors.
diff's documentation
========================
"""
for x in args:
if isinstance(x, BasisDependent):
raise TypeError("Invalid arg for differentiation")
diff_components = [df(v, *args, **kwargs) * k for
k, v in self.components.items()]
return self._add_func(*diff_components)
def diff(self, *args, **kwargs):
"""
Implements the SymPy diff routine, for vectors.
diff's documentation
========================
"""
for x in args:
if isinstance(x, Vector):
raise TypeError("Cannot differentiate wrt a Vector")
diff_components = [df(v, *args, **kwargs) * k for \
k, v in self.components.items()]
return VectorAdd(*diff_components)
