pyFTS.common package¶
Module contents¶
Submodules¶
pyFTS.common.Composite module¶
Composite Fuzzy Sets
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class
pyFTS.common.Composite.
FuzzySet
(name, superset=False, **kwargs)[source]¶ Bases:
pyFTS.common.FuzzySet.FuzzySet
Composite Fuzzy Set
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append
(mf, parameters)[source]¶ Adds a new function to composition
Parameters: - mf –
- parameters –
Returns:
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pyFTS.common.FLR module¶
This module implements functions for Fuzzy Logical Relationship generation
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class
pyFTS.common.FLR.
FLR
(LHS, RHS)[source]¶ Bases:
object
Fuzzy Logical Relationship
Represents a temporal transition of the fuzzy set LHS on time t for the fuzzy set RHS on time t+1.
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LHS
= None¶ Left Hand Side fuzzy set
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RHS
= None¶ Right Hand Side fuzzy set
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class
pyFTS.common.FLR.
IndexedFLR
(index, LHS, RHS)[source]¶ Bases:
pyFTS.common.FLR.FLR
Season Indexed Fuzzy Logical Relationship
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index
= None¶ seasonal index
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pyFTS.common.FLR.
generate_high_order_recurrent_flr
(fuzzyData)[source]¶ Create a ordered FLR set from a list of fuzzy sets with recurrence
Parameters: fuzzyData – ordered list of fuzzy sets Returns: ordered list of FLR
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pyFTS.common.FLR.
generate_indexed_flrs
(sets, indexer, data, transformation=None, alpha_cut=0.0)[source]¶ Create a season-indexed ordered FLR set from a list of fuzzy sets with recurrence
Parameters: - sets – fuzzy sets
- indexer – seasonality indexer
- data – original data
Returns: ordered list of FLR
pyFTS.common.FuzzySet module¶
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class
pyFTS.common.FuzzySet.
FuzzySet
(name, mf, parameters, centroid, alpha=1.0, **kwargs)[source]¶ Bases:
object
Fuzzy Set
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Z
= None¶ Partition function in respect to the membership function
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alpha
= None¶ The alpha cut value
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centroid
= None¶ The fuzzy set center of mass (or midpoint)
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membership
(x)[source]¶ Calculate the membership value of a given input
Parameters: x – input value Returns: membership value of x at this fuzzy set
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mf
= None¶ The membership function
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name
= None¶ The fuzzy set name
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parameters
= None¶ The parameters of the membership function
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partition_function
(uod=None, nbins=100)[source]¶ Calculate the partition function over the membership function.
Parameters: - uod –
- nbins –
Returns:
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transform
(x)[source]¶ Preprocess the data point for non native types
Parameters: x – Returns: return a native type value for the structured type
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type
= None¶ The fuzzy set type (common, composite, nonstationary, etc)
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variable
= None¶ In multivariate time series, indicate for which variable this fuzzy set belogs
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pyFTS.common.FuzzySet.
fuzzyfy
(data, partitioner, **kwargs)[source]¶ A general method for fuzzyfication.
Parameters: - data – input value to be fuzzyfied
- partitioner – a trained pyFTS.partitioners.Partitioner object
- kwargs – dict, optional arguments
- alpha_cut – the minimal membership value to be considered on fuzzyfication (only for mode=’sets’)
- method – the fuzzyfication method (fuzzy: all fuzzy memberships, maximum: only the maximum membership)
- mode – the fuzzyfication mode (sets: return the fuzzy sets names, vector: return a vector with the membership values for all fuzzy sets)
:returns a list with the fuzzyfied values, depending on the mode
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pyFTS.common.FuzzySet.
fuzzyfy_instance
(inst, fuzzy_sets, ordered_sets=None)[source]¶ Calculate the membership values for a data point given fuzzy sets
Parameters: - inst – data point
- fuzzy_sets – a dictionary where the key is the fuzzy set name and the value is the fuzzy set object.
- ordered_sets – a list with the fuzzy sets names ordered by their centroids.
Returns: array of membership values
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pyFTS.common.FuzzySet.
fuzzyfy_instances
(data, fuzzy_sets, ordered_sets=None)[source]¶ Calculate the membership values for a data point given fuzzy sets
Parameters: - inst – data point
- fuzzy_sets – a dictionary where the key is the fuzzy set name and the value is the fuzzy set object.
- ordered_sets – a list with the fuzzy sets names ordered by their centroids.
Returns: array of membership values
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pyFTS.common.FuzzySet.
fuzzyfy_series
(data, fuzzy_sets, method='maximum', alpha_cut=0.0, ordered_sets=None)[source]¶
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pyFTS.common.FuzzySet.
get_fuzzysets
(inst, fuzzy_sets, ordered_sets=None, alpha_cut=0.0)[source]¶ Return the fuzzy sets which membership value for a inst is greater than the alpha_cut
Parameters: - inst – data point
- fuzzy_sets – a dictionary where the key is the fuzzy set name and the value is the fuzzy set object.
- ordered_sets – a list with the fuzzy sets names ordered by their centroids.
- alpha_cut – Minimal membership to be considered on fuzzyfication process
Returns: array of membership values
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pyFTS.common.FuzzySet.
get_maximum_membership_fuzzyset
(inst, fuzzy_sets, ordered_sets=None)[source]¶ Fuzzify a data point, returning the fuzzy set with maximum membership value
Parameters: - inst – data point
- fuzzy_sets – a dictionary where the key is the fuzzy set name and the value is the fuzzy set object.
- ordered_sets – a list with the fuzzy sets names ordered by their centroids.
Returns: fuzzy set with maximum membership
pyFTS.common.Membership module¶
Membership functions for Fuzzy Sets
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pyFTS.common.Membership.
bellmf
(x, parameters)[source]¶ Bell shaped membership function
Parameters: - x –
- parameters –
Returns:
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pyFTS.common.Membership.
gaussmf
(x, parameters)[source]¶ Gaussian fuzzy membership function
Parameters: - x – data point
- parameters – a list with 2 real values (mean and variance)
Returns: the membership value of x given the parameters
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pyFTS.common.Membership.
sigmf
(x, parameters)[source]¶ Sigmoid / Logistic membership function
Parameters: - x –
- parameters – an list with 2 real values (smoothness and midpoint)
Returns:
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pyFTS.common.Membership.
singleton
(x, parameters)[source]¶ Singleton membership function, a single value fuzzy function
Parameters: - x –
- parameters – a list with one real value
:returns
pyFTS.common.SortedCollection module¶
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class
pyFTS.common.SortedCollection.
SortedCollection
(iterable=(), key=None)[source]¶ Bases:
object
Sequence sorted by a key function.
SortedCollection() is much easier to work with than using bisect() directly. It supports key functions like those use in sorted(), min(), and max(). The result of the key function call is saved so that keys can be searched efficiently.
Instead of returning an insertion-point which can be hard to interpret, the five find-methods return a specific item in the sequence. They can scan for exact matches, the last item less-than-or-equal to a key, or the first item greater-than-or-equal to a key.
Once found, an item’s ordinal position can be located with the index() method. New items can be added with the insert() and insert_right() methods. Old items can be deleted with the remove() method.
The usual sequence methods are provided to support indexing, slicing, length lookup, clearing, copying, forward and reverse iteration, contains checking, item counts, item removal, and a nice looking repr.
Finding and indexing are O(log n) operations while iteration and insertion are O(n). The initial sort is O(n log n).
The key function is stored in the ‘key’ attibute for easy introspection or so that you can assign a new key function (triggering an automatic re-sort).
In short, the class was designed to handle all of the common use cases for bisect but with a simpler API and support for key functions.
>>> from pprint import pprint >>> from operator import itemgetter
>>> s = SortedCollection(key=itemgetter(2)) >>> for record in [ ... ('roger', 'young', 30), ... ('angela', 'jones', 28), ... ('bill', 'smith', 22), ... ('david', 'thomas', 32)]: ... s.insert(record)
>>> pprint(list(s)) # show records sorted by age [('bill', 'smith', 22), ('angela', 'jones', 28), ('roger', 'young', 30), ('david', 'thomas', 32)]
>>> s.find_le(29) # find oldest person aged 29 or younger ('angela', 'jones', 28) >>> s.find_lt(28) # find oldest person under 28 ('bill', 'smith', 22) >>> s.find_gt(28) # find youngest person over 28 ('roger', 'young', 30)
>>> r = s.find_ge(32) # find youngest person aged 32 or older >>> s.index(r) # get the index of their record 3 >>> s[3] # fetch the record at that index ('david', 'thomas', 32)
>>> s.key = itemgetter(0) # now sort by first name >>> pprint(list(s)) [('angela', 'jones', 28), ('bill', 'smith', 22), ('david', 'thomas', 32), ('roger', 'young', 30)]
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key
¶ key function
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pyFTS.common.Transformations module¶
Common data transformation used on pre and post processing of the FTS
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class
pyFTS.common.Transformations.
AdaptiveExpectation
(parameters)[source]¶ Bases:
pyFTS.common.Transformations.Transformation
Adaptive Expectation post processing
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apply
(data, param=None, **kwargs)[source]¶ Apply the transformation on input data
Parameters: - data – input data
- param –
- kwargs –
Returns: numpy array with transformed data
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inverse
(data, param, **kwargs)[source]¶ Parameters: - data – transformed data
- param –
- kwargs –
Returns: numpy array with inverse transformed data
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parameters
¶
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class
pyFTS.common.Transformations.
BoxCox
(plambda)[source]¶ Bases:
pyFTS.common.Transformations.Transformation
Box-Cox power transformation
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apply
(data, param=None, **kwargs)[source]¶ Apply the transformation on input data
Parameters: - data – input data
- param –
- kwargs –
Returns: numpy array with transformed data
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inverse
(data, param=None, **kwargs)[source]¶ Parameters: - data – transformed data
- param –
- kwargs –
Returns: numpy array with inverse transformed data
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parameters
¶
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class
pyFTS.common.Transformations.
Differential
(lag)[source]¶ Bases:
pyFTS.common.Transformations.Transformation
Differentiation data transform
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apply
(data, param=None, **kwargs)[source]¶ Apply the transformation on input data
Parameters: - data – input data
- param –
- kwargs –
Returns: numpy array with transformed data
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inverse
(data, param, **kwargs)[source]¶ Parameters: - data – transformed data
- param –
- kwargs –
Returns: numpy array with inverse transformed data
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parameters
¶
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class
pyFTS.common.Transformations.
Scale
(min=0, max=1)[source]¶ Bases:
pyFTS.common.Transformations.Transformation
Scale data inside a interval [min, max]
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apply
(data, param=None, **kwargs)[source]¶ Apply the transformation on input data
Parameters: - data – input data
- param –
- kwargs –
Returns: numpy array with transformed data
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inverse
(data, param, **kwargs)[source]¶ Parameters: - data – transformed data
- param –
- kwargs –
Returns: numpy array with inverse transformed data
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parameters
¶
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class
pyFTS.common.Transformations.
Transformation
(**kwargs)[source]¶ Bases:
object
Data transformation used on pre and post processing of the FTS
pyFTS.common.Util module¶
Common facilities for pyFTS
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pyFTS.common.Util.
current_milli_time
()¶
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pyFTS.common.Util.
distributed_train
(model, train_method, nodes, fts_method, data, num_batches=10, train_parameters={}, **kwargs)[source]¶
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pyFTS.common.Util.
load_obj
(file)[source]¶ Load to memory an object stored filesystem. This function depends on Dill package
Parameters: file – file name where the object is stored Returns: object
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pyFTS.common.Util.
persist_env
(file)[source]¶ Persist an entire environment on file. This function depends on Dill package
Parameters: file – file name to store the environment
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pyFTS.common.Util.
persist_obj
(obj, file)[source]¶ Persist an object on filesystem. This function depends on Dill package
Parameters: - obj – object on memory
- file – file name to store the object
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pyFTS.common.Util.
show_and_save_image
(fig, file, flag, lgd=None)[source]¶ Show and image and save on file
Parameters: - fig – Matplotlib Figure object
- file – filename to save the picture
- flag – if True the image will be saved
- lgd – legend
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pyFTS.common.Util.
sliding_window
(data, windowsize, train=0.8, inc=0.1, **kwargs)[source]¶ Sliding window method of cross validation for time series
Parameters: - data – the entire dataset
- windowsize – window size
- train – percentual of the window size will be used for training the models
- inc – percentual of data used for slide the window
Returns: window count, training set, test set
pyFTS.common.flrg module¶
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class
pyFTS.common.flrg.
FLRG
(order, **kwargs)[source]¶ Bases:
object
Fuzzy Logical Relationship Group
Group a set of FLR’s with the same LHS. Represents the temporal patterns for time t+1 (the RHS fuzzy sets) when the LHS pattern is identified on time t.
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LHS
= None¶ Left Hand Side of the rule
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RHS
= None¶ Right Hand Side of the rule
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get_lower
(sets)[source]¶ Returns the lower bound value for the RHS fuzzy sets
Parameters: sets – fuzzy sets Returns: lower bound value
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get_membership
(data, sets)[source]¶ Returns the membership value of the FLRG for the input data
Parameters: - data – input data
- sets – fuzzy sets
Returns: the membership value
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get_midpoint
(sets)[source]¶ Returns the midpoint value for the RHS fuzzy sets
Parameters: sets – fuzzy sets Returns: the midpoint value
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get_upper
(sets)[source]¶ Returns the upper bound value for the RHS fuzzy sets
Parameters: sets – fuzzy sets Returns: upper bound value
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order
= None¶ Number of lags on LHS
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pyFTS.common.fts module¶
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class
pyFTS.common.fts.
FTS
(**kwargs)[source]¶ Bases:
object
Fuzzy Time Series object model
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alpha_cut
= None¶ A float with the minimal membership to be considered on fuzzyfication process
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apply_inverse_transformations
(data, params=None, **kwargs)[source]¶ Apply the data transformations for data postprocessing
Parameters: - data – input data
- params – transformation parameters
- updateUoD –
- kwargs –
Returns: postprocessed data
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apply_transformations
(data, params=None, updateUoD=False, **kwargs)[source]¶ Apply the data transformations for data preprocessing
Parameters: - data – input data
- params – transformation parameters
- updateUoD –
- kwargs –
Returns: preprocessed data
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auto_update
= None¶ A boolean value indicating that model is incremental
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benchmark_only
= None¶ A boolean value indicating a façade for external (non-FTS) model used on benchmarks or ensembles.
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detail
= None¶ A string with the model detailed information
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fit
(ndata, **kwargs)[source]¶ Fit the model’s parameters based on the training data.
Parameters: - ndata – training time series data
- kwargs –
- num_batches – split the training data in num_batches to save memory during the training process
- save_model – save final model on disk
- batch_save – save the model between each batch
- file_path – path to save the model
- distributed – boolean, indicate if the training procedure will be distributed in a dispy cluster
- nodes – a list with the dispy cluster nodes addresses
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flrgs
= None¶ The list of Fuzzy Logical Relationship Groups - FLRG
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forecast
(data, **kwargs)[source]¶ Point forecast one step ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- kwargs – model specific parameters
Returns: a list with the forecasted values
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forecast_ahead
(data, steps, **kwargs)[source]¶ Point forecast n steps ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- steps – the number of steps ahead to forecast
- start – in the multi step forecasting, the index of the data where to start forecasting
Returns: a list with the forecasted values
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forecast_ahead_distribution
(data, steps, **kwargs)[source]¶ Probabilistic forecast n steps ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- steps – the number of steps ahead to forecast
- kwargs – model specific parameters
Returns: a list with the forecasted Probability Distributions
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forecast_ahead_interval
(data, steps, **kwargs)[source]¶ Interval forecast n steps ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- steps – the number of steps ahead to forecast
- kwargs – model specific parameters
Returns: a list with the forecasted intervals
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forecast_distribution
(data, **kwargs)[source]¶ Probabilistic forecast one step ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- kwargs – model specific parameters
Returns: a list with probabilistic.ProbabilityDistribution objects representing the forecasted Probability Distributions
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forecast_interval
(data, **kwargs)[source]¶ Interval forecast one step ahead
Parameters: - data – time series data with the minimal length equal to the max_lag of the model
- kwargs – model specific parameters
Returns: a list with the prediction intervals
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fuzzy
(data)[source]¶ Fuzzify a data point
Parameters: data – data point Returns: maximum membership fuzzy set
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has_interval_forecasting
= None¶ A boolean value indicating if the model supports interval forecasting, default: False
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has_point_forecasting
= None¶ A boolean value indicating if the model supports point forecasting, default: True
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has_probability_forecasting
= None¶ A boolean value indicating if the model support probabilistic forecasting, default: False
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has_seasonality
= None¶ A boolean value indicating if the model supports seasonal indexers, default: False
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indexer
= None¶ An pyFTS.models.seasonal.Indexer object for indexing the time series data
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is_high_order
= None¶ A boolean value indicating if the model support orders greater than 1, default: False
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is_multivariate
= None¶ A boolean value indicating if the model support multivariate time series (Pandas DataFrame), default: False
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max_lag
= None¶ A integer indicating the largest lag used by the model. This value also indicates the minimum number of past lags needed to forecast a single step ahead
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merge
(model)[source]¶ Merge the FLRG rules from other model
Parameters: model – source model Returns:
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min_order
= None¶ In high order models, this integer value indicates the minimal order supported for the model, default: 1
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name
= None¶ A string with the model name
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order
= None¶ A integer with the model order (number of past lags are used on forecasting)
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original_max
= None¶ A float with the upper limit of the Universe of Discourse, the maximal value found on training data
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original_min
= None¶ A float with the lower limit of the Universe of Discourse, the minimal value found on training data
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partitioner
= None¶ A pyFTS.partitioners.Partitioner object with the Universe of Discourse partitioner used on the model. This is a mandatory dependecy.
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predict
(data, **kwargs)[source]¶ Forecast using trained model
Parameters: - data – time series with minimal length to the order of the model
- type – the forecasting type, one of these values: point(default), interval or distribution.
- steps_ahead – The forecasting horizon, i. e., the number of steps ahead to forecast
- start – in the multi step forecasting, the index of the data where to start forecasting
- distributed – boolean, indicate if the forecasting procedure will be distributed in a dispy cluster
- nodes – a list with the dispy cluster nodes addresses
- explain – try to explain, step by step, the one-step-ahead point forecasting result given the input data.
- generators – for multivariate methods on multi step ahead forecasting, generators is a dict where the keys are the variables names (except the target_variable) and the values are lambda functions that accept one value (the actual value of the variable) and return the next value.
Returns: a numpy array with the forecasted data
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sets
= None¶ The list of fuzzy sets used on this model
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shortname
= None¶ A string with a short name or alias for the model
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train
(data, **kwargs)[source]¶ Method specific parameter fitting
Parameters: - data – training time series data
- kwargs – Method specific parameters
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transformations
= None¶ A list with the data transformations (common.Transformations) applied on model pre and post processing, default: []
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transformations_param
= None¶ A list with the specific parameters for each data transformation
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uod_clip
= None¶ Flag indicating if the test data will be clipped inside the training Universe of Discourse
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