def __init__(self, rest_length=0.0):
Terminus.__init__(self)
self.coordinates = []
self.frames = []
if rest_length < 0.0:
raise Error("The rest length of a spring must be zero or positive.")
self.rest_length = rest_length
def __init__(self, rest_length=0.0):
Terminus.__init__(self)
self.coordinates = []
self.frames = []
if rest_length < 0.0:
raise Error(
"The rest length of a spring must be zero or positive.")
self.rest_length = rest_length
def sanity_check(self):
if len(self.frames) != 2:
raise Error("A Spring expression needs two frames.")
if len(self.input_variables) > 2:
raise Error("A Spring expression needs at most two input_variables.")
if len(self.coordinates) != 2:
raise Error("A Spring energy term must have two coordinates.")
Terminus.sanity_check(self)
def register_input_variable(self, variable, coordinate):
if not (isinstance(variable, Frame) or isinstance(variable, Translation) or isinstance(variable, NoFrame)):
raise Error("Expression requires iterative.var.Frame or iterative.var.Translation as variable")
self.coordinates.append(coordinate)
self.frames.append(variable)
if not isinstance(variable, NoFrame):
variable.add_mass(coordinate)
Terminus.register_input_variable(self, variable)
def sanity_check(self):
if len(self.frames) != 2:
raise Error("A Spring expression needs two frames.")
if len(self.input_variables) > 2:
raise Error(
"A Spring expression needs at most two input_variables.")
if len(self.coordinates) != 2:
raise Error("A Spring energy term must have two coordinates.")
Terminus.sanity_check(self)
def register_input_variable(self, variable, coordinate):
if not (isinstance(variable, Frame) or isinstance(
variable, Translation) or isinstance(variable, NoFrame)):
raise Error(
"Expression requires iterative.var.Frame or iterative.var.Translation as variable"
)
self.coordinates.append(coordinate)
self.frames.append(variable)
if not isinstance(variable, NoFrame):
variable.add_mass(coordinate)
Terminus.register_input_variable(self, variable)
