def update_sankey(self, demand, method, cut_off=0.05, max_calc=100):
"""Calculate LCA, do graph traversal, get JSON graph data for this, and send to javascript."""
print("Demand / Method:", demand, method)
start = time.time()
try:
data = bw.GraphTraversal().calculate(demand, method, cutoff=cut_off, max_calc=max_calc)
except ValueError as e:
QtWidgets.QMessageBox.information(None, "Not possible.", str(e))
print("Completed graph traversal ({:.2g} seconds, {} iterations)".format(time.time() - start, data["counter"]))
self.graph.new_graph(data)
# print("emitting graph ready signal")
self.send_json()
def filter_technosphere_exchanges(fu, method, cutoff=0.05, max_calc=1e4):
"""Use brightway's GraphTraversal to identify the relevant
technosphere exchanges in a non-stochastic LCA."""
start = time()
res = bw.GraphTraversal().calculate(fu, method, cutoff=cutoff, max_calc=max_calc)
# get all edges
technosphere_exchange_indices = []
for e in res['edges']:
if e['to'] != -1: # filter out head introduced in graph traversal
technosphere_exchange_indices.append((e['from'], e['to']))
print('TECHNOSPHERE {} filtering resulted in {} of {} exchanges and took {} iterations in {} seconds.'.format(
res['lca'].technosphere_matrix.shape,
len(technosphere_exchange_indices),
res['lca'].technosphere_matrix.getnnz(),
res['counter'],
np.round(time() - start, 2),
))
return technosphere_exchange_indices
def run(self):
res = bw.GraphTraversal().calculate(self.demand, self.method,
self.cutoff, self.max_calc)
sankeysignals.gt_ready.emit(res)