import itertools
import string
import sys
from warnings import warn
import bw2calc as bc
import numpy as np
import pandas as pd
import pyprind
from bw2data import Database, databases, get_activity, methods
[docs]
def contribution_for_all_datasets_one_method(database, method, progress=True):
"""Calculate contribution analysis (for technosphere processes) for all inventory datasets in one database for one LCIA method.
Args:
*database* (str): Name of database
*method* (tuple): Method tuple
Returns:
NumPy array of relative contributions. Each column sums to one.
Lookup dictionary, dataset keys to row/column indices
"""
def get_normalized_scores(lca, kind):
if kind == "activities":
data = lca.characterized_inventory.sum(axis=0)
elif kind == "flows":
data = lca.characterized_inventory.sum(axis=1)
elif kind == "all":
data = lca.characterized_inventory.data
scores = np.abs(np.array(data).ravel())
summed = scores.sum()
if summed == 0:
return np.zeros(scores.shape)
else:
return scores / summed
assert database in databases, f"Can't find database {database}"
assert method in methods, f"Can't find method {method}"
db = Database(database)
assert len(db), f"Database {database} appears to have no datasets"
# Array to store results
results = np.zeros((len(db), len(db)), dtype=np.float32)
# Instantiate LCA object
lca = bc.LCA({db.random(): 1}, method=method)
lca.lci()
lca.lcia()
rows = lca.characterized_inventory.shape[0]
cols = lca.characterized_inventory.shape[1]
all_cutoff = cols * 4
results = {
"activities": np.zeros((cols, cols), dtype=np.float32),
"flows": np.zeros((rows, cols), dtype=np.float32),
"all": np.zeros((all_cutoff, cols), dtype=np.float32),
}
pbar = pyprind.ProgBar(len(db), title="Activities:")
# Actual calculations
for ds in db:
lca.redo_lcia({ds.id: 1})
if not lca.score:
continue
col = lca.dicts.activity[ds.id]
results["activities"][:, col] = get_normalized_scores(lca, "activities")
results["flows"][:, col] = get_normalized_scores(lca, "flows")
results_all = get_normalized_scores(lca, "all")
results_all.sort()
results_all = results_all[::-1]
fill_number = results_all.shape[0]
assert fill_number < all_cutoff, "Too many values in 'all'"
results["all"][:fill_number, col] = results_all
pbar.update()
print(pbar)
return results
[docs]
def print_recursive_calculation(
activity,
lcia_method,
amount=1,
max_level=3,
cutoff=1e-2,
string_length=130,
file_obj=None,
tab_character=" ",
use_matrix_values=False,
_lca_obj=None,
_total_score=None,
__level=0,
__first=True,
):
"""Traverse a supply chain graph, and calculate the LCA scores of each component. Prints the result with the format:
{tab_character * level }{fraction of total score} ({absolute LCA score for this input} | {amount of input}) {input activity}
Args:
activity: ``Activity``. The starting point of the supply chain graph.
lcia_method: tuple. LCIA method to use when traversing supply chain graph.
amount: int. Amount of ``activity`` to assess.
max_level: int. Maximum depth to traverse.
cutoff: float. Fraction of total score to use as cutoff when deciding whether to traverse deeper.
string_length: int. Maximum length of printed string.
file_obj: File-like object (supports ``.write``), optional. Output will be written to this object if provided.
tab_character: str. Character to use to indicate indentation.
use_matrix_values: bool. Take exchange values from the matrix instead of the exchange instance ``amount``. Useful for Monte Carlo, but can be incorrect if there is more than one exchange from the same pair of nodes.
Normally internal args:
_lca_obj: ``LCA``. Can give an instance of the LCA class (e.g. when doing regionalized or Monte Carlo LCA)
_total_score: float. Needed if specifying ``_lca_obj``.
Internal args (used during recursion, do not touch);
__level: int.
__first: bool.
Returns:
Nothing. Prints to ``sys.stdout`` or ``file_obj``
"""
activity = get_activity(activity)
if file_obj is None:
file_obj = sys.stdout
if _lca_obj is None:
_lca_obj = bc.LCA({activity: amount}, lcia_method)
_lca_obj.lci()
_lca_obj.lcia()
_total_score = _lca_obj.score
elif _total_score is None:
raise ValueError
else:
_lca_obj.redo_lcia({activity.id: amount})
if abs(_lca_obj.score) <= abs(_total_score * cutoff):
return
if __first:
file_obj.write("Fraction of score | Absolute score | Amount | Activity\n")
message = "{}{:04.3g} | {:5.4n} | {:5.4n} | {}".format(
tab_character * __level,
_lca_obj.score / _total_score,
_lca_obj.score,
float(amount),
str(activity),
)
file_obj.write(message[:string_length] + "\n")
if __level < max_level:
prod_exchanges = list(activity.production())
if not prod_exchanges:
prod_amount = 1
elif len(prod_exchanges) > 1:
warn("Hit multiple production exchanges; aborting in this branch")
return
else:
prod_amount = _lca_obj.technosphere_matrix[
_lca_obj.dicts.product[prod_exchanges[0].input.id],
_lca_obj.dicts.activity[prod_exchanges[0].output.id],
]
for exc in activity.technosphere():
if exc.input.id == exc.output.id:
continue
if use_matrix_values:
sign = (
-1
if exc.get("type") in ("technosphere", "generic technosphere")
else 1
)
tm_amount = (
_lca_obj.technosphere_matrix[
_lca_obj.dicts.product[exc.input.id],
_lca_obj.dicts.activity[exc.output.id],
]
* sign
)
else:
tm_amount = exc["amount"]
print_recursive_calculation(
activity=exc.input,
lcia_method=lcia_method,
amount=amount * tm_amount / prod_amount,
max_level=max_level,
cutoff=cutoff,
string_length=string_length,
file_obj=file_obj,
tab_character=tab_character,
__first=False,
_lca_obj=_lca_obj,
_total_score=_total_score,
__level=__level + 1,
)
[docs]
def print_recursive_supply_chain(
activity,
amount=1,
max_level=2,
cutoff=0,
string_length=130,
file_obj=None,
tab_character=" ",
__level=0,
):
"""Traverse a supply chain graph, and prints the inputs of each component.
This function is only for exploration; use ``bw2calc.GraphTraversal`` for a better performing function.
The results displayed here can also be incorrect if
Args:
activity: ``Activity``. The starting point of the supply chain graph.
amount: int. Supply chain inputs will be scaled to this value.
max_level: int. Max depth to search for.
cutoff: float. Inputs with amounts less than ``amount * cutoff`` will not be printed or traversed further.
string_length: int. Maximum length of each line.
file_obj: File-like object (supports ``.write``), optional. Output will be written to this object if provided.
tab_character: str. Character to use to indicate indentation.
__level: int. Current level of the calculation. Only used internally, do not touch.
Returns:
Nothing. Prints to ``stdout`` or ``file_obj``
"""
activity = get_activity(activity)
if file_obj is None:
file_obj = sys.stdout
if cutoff > 0 and amount < cutoff:
return
message = "{}{:.3g}: {}".format(tab_character * __level, amount, str(activity))
file_obj.write(message[:string_length] + "\n")
if __level < max_level:
prod_exchanges = list(activity.production())
if not prod_exchanges:
prod_amount = 1
elif len(prod_exchanges) > 1:
warn("Hit multiple production exchanges; aborting in this branch")
return
else:
prod_amount = prod_exchanges[0]["amount"]
for other in activity.technosphere():
if other.input == prod_exchanges[0].input:
prod_amount -= other["amount"]
for exc in activity.technosphere():
if exc.input.id == exc.output.id:
continue
print_recursive_supply_chain(
activity=exc.input,
amount=amount * exc["amount"] / prod_amount,
max_level=max_level,
cutoff=cutoff,
string_length=string_length,
file_obj=file_obj,
tab_character=tab_character,
__level=__level + 1,
)
[docs]
def infinite_alphabet():
"""Return generator with values a-z, then aa-az, ba-bz, then aaa-aaz, aba-abz, etc."""
for value in itertools.chain.from_iterable(
itertools.product(string.ascii_lowercase, repeat=i) for i in itertools.count(1)
):
yield "".join(value)
[docs]
def recursive_calculation_to_object(
activity,
lcia_method,
amount=1,
max_level=3,
cutoff=1e-2,
as_dataframe=False,
root_label="root",
use_matrix_values=False,
_lca_obj=None,
_total_score=None,
__result_list=None,
__level=0,
__label="",
__parent=None,
):
"""Traverse a supply chain graph, and calculate the LCA scores of each component. Adds a dictionary to ``result_list`` of the form:
{
'label': Label of this branch. Starts with nothing, then A, AA, AB, AAA, AAB, etc.
'score': Absolute score of this activity
'fraction': Fraction of total score of this activity
'amount': Input amount of the reference product of this activity
'name': Name of this activity
'key': Activity key
'root_label': Starting label of root element for recursion.
}
Args:
activity: ``Activity``. The starting point of the supply chain graph.
lcia_method: tuple. LCIA method to use when traversing supply chain graph.
amount: int. Amount of ``activity`` to assess.
max_level: int. Maximum depth to traverse.
cutoff: float. Fraction of total score to use as cutoff when deciding whether to traverse deeper.
as_dataframe: Return results as a list (default) or a pandas ``DataFrame``
use_matrix_values: bool. Take exchange values from the matrix instead of the exchange instance ``amount``. Useful for Monte Carlo, but can be incorrect if there is more than one exchange from the same pair of nodes.
Internal args (used during recursion, do not touch):
__result_list: list.
__level: int.
__label: str.
__parent: str.
Returns:
List of dicts
"""
activity = get_activity(activity)
if __result_list is None:
__result_list = []
__label = root_label
if _lca_obj is None:
_lca_obj = bc.LCA({activity: amount}, lcia_method)
_lca_obj.lci()
_lca_obj.lcia()
_total_score = _lca_obj.score
elif _total_score is None:
raise ValueError
else:
_lca_obj.redo_lcia({activity.id: amount})
if abs(_lca_obj.score) <= abs(_total_score * cutoff):
return
__result_list.append(
{
"label": __label,
"parent": __parent,
"score": _lca_obj.score,
"fraction": _lca_obj.score / _total_score,
"amount": float(amount),
"name": activity.get("name", "(Unknown name)"),
"key": activity.key,
}
)
if __level < max_level:
prod_exchanges = list(activity.production())
if not prod_exchanges:
prod_amount = 1
elif len(prod_exchanges) > 1:
warn(
"Hit multiple production exchanges for {}; aborting in this branch".format(
activity
)
)
return
else:
prod_amount = _lca_obj.technosphere_matrix[
_lca_obj.dicts.product[prod_exchanges[0].input.id],
_lca_obj.dicts.activity[prod_exchanges[0].output.id],
]
for child_label, exc in zip(infinite_alphabet(), activity.technosphere()):
if exc.input.id == exc.output.id:
continue
if use_matrix_values:
sign = (
-1
if exc.get("type") in ("technosphere", "generic technosphere")
else 1
)
tm_amount = (
_lca_obj.technosphere_matrix[
_lca_obj.dicts.product[exc.input.id],
_lca_obj.dicts.activity[exc.output.id],
]
* sign
)
else:
tm_amount = exc["amount"]
recursive_calculation_to_object(
activity=exc.input,
lcia_method=lcia_method,
amount=amount * tm_amount / prod_amount,
max_level=max_level,
cutoff=cutoff,
as_dataframe=as_dataframe,
__result_list=__result_list,
__parent=__label,
__label=__label + "_" + child_label if __label else child_label,
_lca_obj=_lca_obj,
_total_score=_total_score,
__level=__level + 1,
)
if as_dataframe and __label == root_label:
return pd.DataFrame(__result_list)
else:
return __result_list
