pywr.nodes.LossLink

class pywr.nodes.LossLink(*args, **kwargs)

A node that has a proportional loss.

A fixed proportional loss of all flow through this node is sent to an internal output node. Max and min flows applied to this node are enforced on the net output after losses. The node itself records the net output in its flow attribute (which would be used by any attached recorders).

Parameters:

modelpywr.model.Model

namestring

Name of the node.

loss_factorfloat, Parameter

The proportion of flow that is lost through this node. Must be greater than or equal to zero. If zero then no-losses are calculated. This value is either a proportion of gross or net flow depending on the value of loss_factor_type.

loss_factor_type: str

Either “gross” or “net” (default) to specify whether the loss factor is applied as a proportion of gross or

net flow respectively.

Notes

There is currently a limitation that the loss factor must be a literal constant (i.e. not a parameter) when loss_factor_type is set to “gross”.

__init__(model, name, **kwargs)

Initialise a new Node object

Parameters:

modelModel

The model the node belongs to

namestring

A unique name for the node

Methods

__init__(model, name, **kwargs)	Initialise a new Node object
after(self, Timestep ts)
before(self, Timestep ts)	Called at the beginning of the timestep
check()	Check the node is valid
commit(self, int scenario_index, double value)	Called once for each route the node is a member of
commit_all(self, double[)	Called once for each route the node is a member of
connect(node[, from_slot, to_slot])	Create an edge from this Node to another Node
disconnect([node, slot_name, all_slots])	Remove a connection from this Node to another Node
finalise_load()	Finish loading a node by converting parameter name references to instance references.
finish(self)
get_all_cost(self, double[)
get_all_max_flow(self, double[)
get_all_min_flow(self, double[)
get_constant_max_flow(self)	Returns max_flow value if it is a constant parameter or fixed value otherwise returns NaN.
get_constant_min_flow(self)	Returns min_flow value if it is a constant parameter or fixed value otherwise returns NaN.
get_conversion_factor(self)	Get the conversion factor
get_cost(self, ScenarioIndex scenario_index)	Get the cost per unit flow at a given timestep
get_fixed_max_flow(self)	Returns max_flow value if it is fixed value otherwise returns NaN.
get_fixed_min_flow(self)	Returns min_flow value if it is a fixed value otherwise returns NaN.
get_max_flow(self, ScenarioIndex scenario_index)	Get the maximum flow at a given timestep
get_min_flow(self, ScenarioIndex scenario_index)	Get the minimum flow at a given timestep
iter_slots([slot_name, is_connector])	Returns the object(s) wich should be connected to given slot_name
pre_load(model, data)	Create a node instance from data.
reset(self)	Called at the beginning of a run
setup(self, model)	Called before the first run of the model

Attributes

allow_isolated	A property to flag whether this Node can be unconnected in a network.
comment	comment: basestring
component_attrs
components	Generator that returns all of the Components attached to the Node
conversion_factor	The conversion between inflow and outflow for the node
cost	The cost per unit flow via the node
domain
flow	Total flow via this node in the current timestep
fully_qualified_name
has_constant_flows	Returns true if both min_flow and max_flow are literal constants or "constant" Parameters.
has_fixed_cost	Returns true if cost is not a Parameter.
has_fixed_flows	Returns true if both min_flow and max_flow are not Parameters.
max_flow	The maximum flow constraint on the node
min_flow	The minimum flow constraint on the node
model	The recorder for the node, e.g. a NumpyArrayRecorder.
name	Name of the node.
parent	The parent Node/Storage of this object.
prev_flow	Total flow via this node in the previous timestep
recorders	Returns a list of pywr.recorders.Recorder objects attached to this node.
virtual	virtual: 'bool'