Source code for aequilibrae.paths.optimal_strategies
import logging
from scipy import sparse
import numpy as np
from aequilibrae.paths.public_transport import HyperpathGenerating
[docs]
class OptimalStrategies:
[docs]
def __init__(self, assig_spec):
from aequilibrae.paths import TransitAssignment
self.__assig_spec = assig_spec # type: TransitAssignment
self.__logger = assig_spec.logger
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def execute(self):
self.__classes = {}
self.__results = {}
self.__demand_cols = {}
for cls in self.__assig_spec.classes:
cls.results.prepare(cls.graph, cls.matrix)
self.__results[cls._id] = cls.results
try:
# converts 0 based array with custom index to COO matrix, ignores custom index
idx = cls.matrix.view_names.index(cls.matrix_core)
demand = sparse.coo_matrix(
(
cls.matrix.matrix_view[:, :, idx]
if len(cls.matrix.view_names) > 1
else cls.matrix.matrix_view[:, :]
),
dtype=np.float64,
)
except ValueError as e:
raise ValueError(
f"matrix core {cls.matrix_core} not found in matrix view. Ensure the matrix is prepared and the core exists"
) from e
# Take the COO matrix and lookup the index values (taz_id)
taz_row = cls.matrix.index[demand.row]
taz_col = cls.matrix.index[demand.col]
# Since the aeq matrix indexes based on centroids, and the transit graph can make the distinction between
# origins and destinations, We need to translate the index of the cols in to the destination node_ids for
# the assignment
od_node_mapping = cls.graph.od_node_mapping.copy()
od_node_mapping["idx"] = od_node_mapping.index
od_node_mapping = od_node_mapping.set_index("taz_id")
o_key, d_key = (
("node_id", "node_id") if len(cls.graph.od_node_mapping.columns) == 2 else ("o_node_id", "d_node_id")
)
# map taz_id, taz_id -> O, D, demand value triplet
self.__demand_cols[cls._id] = {
"origin_column": od_node_mapping.loc[taz_row, o_key].to_numpy().astype(np.uint32),
"destination_column": od_node_mapping.loc[taz_col, d_key].values.astype(np.uint32),
"demand_column": demand.data,
}
self.__classes[cls._id] = HyperpathGenerating(
cls.graph.graph,
head="a_node",
tail="b_node",
trav_time=self.__assig_spec._config["Time field"],
freq=self.__assig_spec._config["Frequency field"],
skim_cols=self.__assig_spec._config["Skimming Fields"],
o_vert_ids=od_node_mapping[o_key].to_numpy(), # taz_id
d_vert_ids=od_node_mapping[d_key].to_numpy(), # node_id for destination in the above taz_id
nodes_to_indices=cls.graph.nodes_to_indices,
)
for cls in self.__assig_spec.classes:
hyperpath = self.__classes[cls._id]
self.__logger.info(f"Executing S&F assignment for {cls._id}")
hyperpath.assign(**self.__demand_cols[cls._id], threads=self.__assig_spec.cores)
self.__results[cls._id].link_loads = hyperpath._edges["volume"].values
if hyperpath._skimming:
skim = hyperpath.skim_matrix
# skim.index = cls.graph.centroids[:]
self.__results[cls._id].skims = skim