chainladder.VotingChainladder#
- class chainladder.VotingChainladder(estimators, *, weights=None, default_weighting=None, n_jobs=None, verbose=False)#
Prediction voting chainladder method for unfitted estimators.
A voting chainladder is an ensemble meta-estimator that fits several base chainladder methods, each on the whole triangle. Then it combines the individual predictions based on a matrix of weights to form a final prediction.
Read more in the User Guide.
New in version 0.8.0.
- Parameters:
- estimators: list of (str, estimator) tuples
Invoking the
fit
method on theVotingChainladder
will fit clones of those original estimators that will be stored in the class attributeself.estimators_
. An estimator can be set to'drop'
usingset_params
.- weights: array callable or dict, default=None
array
: Numpy array of shape (index, columns, origin, n_estimators). Minimum shape required is (origin, n_estimators). Lower dimensional weight arrays will have missing dimensions repeated to match the shape of the triangle.list
: List of weights where each weight is a list of length n_estimators.dict
: A dictionary where the origin is mapped to a weighting tuple. Missing origin periods will be givendefault_weighting
.callable
: A callable that returns weighting tuples.None
usesdefault_weighting
.- default_weighting: tuple of shape (n_estimators, ), default=None
Default weighting to use where a weight was not provided or if
weights
is None.None
uses a typle of all ones which is equivalent to averaging the predictions of the estimators.- n_jobs: int, default=None
The number of jobs to run in parallel for
fit
.None
means 1 unless in ajoblib.parallel_backend
context.-1
means using all processors. for more details.- verbose: bool, default=False
If True, the time elapsed while fitting will be printed as it is completed.
Examples
>>> import numpy as np >>> import chainladder as cl >>> raa = cl.load_sample('RAA') >>> cl_ult = cl.Chainladder().fit(raa).ultimate_ # Chainladder Ultimate >>> apriori = cl_ult * 0 + (float(cl_ult.sum()) / 10) # Mean Chainladder Ultimate >>> bcl = cl.Chainladder() >>> bf = cl.BornhuetterFerguson() >>> cc = cl.CapeCod() >>> estimators = [('bcl', bcl), ('bf', bf), ('cc', cc)] >>> weights = np.array([[0.6, 0.2, 0.2]] * 4 + [[0, 0.5, 0.5]] * 3 + [[0, 0, 1]] * 3) >>> vot = cl.VotingChainladder(estimators=estimators, weights=weights) >>> vot.fit(raa, sample_weight=apriori) >>> print(vot.ultimate_) 2262 1981 18834.000000 1982 16875.500226 1983 24058.534810 1984 28542.580970 1985 28236.843134 1986 19905.317262 1987 18947.245455 1988 23106.943030 1989 20004.502125 1990 21605.832631
- Attributes:
- estimators_: list of chainladder estimators
The collection of fitted sub-estimators as defined in
estimators
that are not ‘drop’.- named_estimators_: Bunch
Attribute to access any fitted sub-estimators by name.
Methods
fit
(X[, y, sample_weight])Fit the estimators.
fit_transform
(X[, y, sample_weight])Fit and return predictions for VotingChainladder
get_metadata_routing
()Get metadata routing of this object.
get_params
([deep])Get the parameters of an estimator from the ensemble.
intersection
(a, b)Given two Triangles with mismatched indices, this method aligns their indices
predict
(X[, sample_weight])Predicts the voting chainladder ultimate on a new triangle X
set_backend
(backend[, inplace, deep])Converts triangle array_backend.
set_fit_request
(*[, sample_weight])Request metadata passed to the
fit
method.set_output
(*[, transform])Set output container.
set_params
(**params)Set the parameters of an estimator from the ensemble.
set_predict_request
(*[, sample_weight])Request metadata passed to the
predict
method.set_transform_request
(*[, sample_weight])Request metadata passed to the
transform
method.to_json
()Serializes triangle object to json format
to_pickle
(path[, protocol])Serializes triangle object to pickle.
transform
(X[, sample_weight])Return predictions for VotingChainladder
fit_predict
pipe
validate_X
validate_weight