Table Of Contents
Table Of Contents

Source code for gluonts.model.r_forecast._predictor

# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# or in the "license" file accompanying this file. This file is distributed
# on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
# express or implied. See the License for the specific language governing
# permissions and limitations under the License.

# Standard library imports
import os
from typing import Dict, Iterator, Optional

# Third-party imports
import numpy as np
import pandas as pd

# First-party imports
from gluonts.core.component import validated
from gluonts.dataset.common import Dataset
from gluonts.evaluation import get_seasonality
from gluonts.model.forecast import SampleForecast
from gluonts.model.predictor import RepresentablePredictor

USAGE_MESSAGE = """
The RForecastPredictor is a thin wrapper for calling the R forecast package.
In order to use it you need to install R and run

pip install rpy2

R -e 'install.packages(c("forecast", "nnfor"), repos="https://cloud.r-project.org")'
"""


[docs]class RForecastPredictor(RepresentablePredictor): """ Wrapper for calling the `R forecast package <http://pkg.robjhyndman.com/forecast/>`_. The `RForecastPredictor` is a thin wrapper for calling the R forecast package. In order to use it you need to install R and run:: pip install rpy2 R -e 'install.packages(c("forecast", "nnfor"), repos="https://cloud.r-project.org")' Parameters ---------- method The method from rforecast to be used one of "ets", "arima", "tbats", "croston", "mlp". prediction_length Number of time points to be predicted. freq The granularity of the time series (e.g. '1H') period The period to be used (this is called `frequency` in the R forecast package), result to a tentative reasonable default if not specified (for instance 24 for hourly freq '1H') num_samples Number of samples to draw. trunc_length Maximum history length to feed to the model (some models become slow with very long series). params Parameters to be used when calling the forecast method default. Note that currently only `output_type = 'samples'` is supported. """ @validated() def __init__( self, freq: str, prediction_length: int, method_name: str = "ets", period: int = None, num_eval_samples: int = 100, trunc_length: Optional[int] = None, params: Optional[Dict] = None, ) -> None: try: from rpy2 import robjects, rinterface import rpy2.robjects.packages as rpackages from rpy2.rinterface import RRuntimeError except ImportError as e: raise ImportError(str(e) + USAGE_MESSAGE) from e self._robjects = robjects self._rinterface = rinterface self._rinterface.initr() self._rpackages = rpackages this_dir = os.path.dirname(os.path.realpath(__file__)) r_files = [ n[:-2] for n in os.listdir(f"{this_dir}/R/") if n[-2:] == ".R" ] for n in r_files: try: robjects.r(f'source("{this_dir}/R/{n}.R")') except RRuntimeError as er: raise RRuntimeError(str(er) + USAGE_MESSAGE) from er supported_methods = ["ets", "arima", "tbats", "croston", "mlp"] assert ( method_name in supported_methods ), f"method {method_name} is not supported please use one of {supported_methods}" self.method_name = method_name self._stats_pkg = rpackages.importr("stats") self._r_method = robjects.r[method_name] self.prediction_length = prediction_length self.freq = freq self.period = period if period is not None else get_seasonality(freq) self.num_samples = num_eval_samples self.trunc_length = trunc_length self.params = { "prediction_length": self.prediction_length, "output_types": ["samples"], "num_samples": self.num_samples, "frequency": self.period, } if params is not None: self.params.update(params) def _unlist(self, l): if type(l).__name__.endswith("Vector"): return [self._unlist(x) for x in l] else: return l def _run_r_forecast(self, d, params, save_info): buf = [] def save_to_buf(x): buf.append(x) def dont_save(x): pass f = save_to_buf if save_info else dont_save # save output from the R console in buf self._rinterface.set_writeconsole_regular(f) self._rinterface.set_writeconsole_warnerror(f) make_ts = self._stats_pkg.ts r_params = self._robjects.vectors.ListVector(params) vec = self._robjects.FloatVector(d["target"]) ts = make_ts(vec, frequency=self.period) forecast = self._r_method(ts, r_params) forecast_dict = dict( zip(forecast.names, map(self._unlist, list(forecast))) ) # FOR NOW ONLY SAMPLES... # if "quantiles" in forecast_dict: # forecast_dict["quantiles"] = dict(zip(params["quantiles"], forecast_dict["quantiles"])) self._rinterface.set_writeconsole_regular( self._rinterface.consolePrint ) self._rinterface.set_writeconsole_warnerror( self._rinterface.consolePrint ) return forecast_dict, buf
[docs] def predict( self, dataset: Dataset, num_samples=None, save_info=False, **kwargs ) -> Iterator[SampleForecast]: for entry in dataset: if isinstance(entry, dict): data = entry else: data = entry.data if self.trunc_length: data = data[-self.trunc_length :] params = self.params.copy() if num_samples is not None: params["num_samples"] = num_samples forecast_dict, console_output = self._run_r_forecast( data, params, save_info=save_info ) forecast_start = ( pd.Timestamp(data["start"], freq=self.freq) + data["target"].shape[0] ) samples = np.array(forecast_dict["samples"]) expected_shape = (params["num_samples"], self.prediction_length) assert ( samples.shape == expected_shape ), f"Expected shape {expected_shape} but found {samples.shape}" info = ( {"console_output": "\n".join(console_output)} if save_info else None ) yield SampleForecast( samples, forecast_start, forecast_start.freqstr, info=info )