laywerrobot/lib/python3.6/site-packages/sklearn/datasets/california_housing.py

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2020-08-27 21:55:39 +02:00
"""California housing dataset.
The original database is available from StatLib
http://lib.stat.cmu.edu/datasets/
The data contains 20,640 observations on 9 variables.
This dataset contains the average house value as target variable
and the following input variables (features): average income,
housing average age, average rooms, average bedrooms, population,
average occupation, latitude, and longitude in that order.
References
----------
Pace, R. Kelley and Ronald Barry, Sparse Spatial Autoregressions,
Statistics and Probability Letters, 33 (1997) 291-297.
"""
# Authors: Peter Prettenhofer
# License: BSD 3 clause
from os.path import exists
from os import makedirs, remove
import tarfile
import numpy as np
import logging
from .base import get_data_home
from .base import _fetch_remote
from .base import _pkl_filepath
from .base import RemoteFileMetadata
from ..utils import Bunch
from ..externals import joblib
# The original data can be found at:
# http://www.dcc.fc.up.pt/~ltorgo/Regression/cal_housing.tgz
ARCHIVE = RemoteFileMetadata(
filename='cal_housing.tgz',
url='https://ndownloader.figshare.com/files/5976036',
checksum=('aaa5c9a6afe2225cc2aed2723682ae40'
'3280c4a3695a2ddda4ffb5d8215ea681'))
# Grab the module-level docstring to use as a description of the
# dataset
MODULE_DOCS = __doc__
logger = logging.getLogger(__name__)
def fetch_california_housing(data_home=None, download_if_missing=True):
"""Loader for the California housing dataset from StatLib.
Read more in the :ref:`User Guide <datasets>`.
Parameters
----------
data_home : optional, default: None
Specify another download and cache folder for the datasets. By default
all scikit-learn data is stored in '~/scikit_learn_data' subfolders.
download_if_missing : optional, True by default
If False, raise a IOError if the data is not locally available
instead of trying to download the data from the source site.
Returns
-------
dataset : dict-like object with the following attributes:
dataset.data : ndarray, shape [20640, 8]
Each row corresponding to the 8 feature values in order.
dataset.target : numpy array of shape (20640,)
Each value corresponds to the average house value in units of 100,000.
dataset.feature_names : array of length 8
Array of ordered feature names used in the dataset.
dataset.DESCR : string
Description of the California housing dataset.
Notes
------
This dataset consists of 20,640 samples and 9 features.
"""
data_home = get_data_home(data_home=data_home)
if not exists(data_home):
makedirs(data_home)
filepath = _pkl_filepath(data_home, 'cal_housing.pkz')
if not exists(filepath):
if not download_if_missing:
raise IOError("Data not found and `download_if_missing` is False")
logger.info('Downloading Cal. housing from {} to {}'.format(
ARCHIVE.url, data_home))
archive_path = _fetch_remote(ARCHIVE, dirname=data_home)
with tarfile.open(mode="r:gz", name=archive_path) as f:
cal_housing = np.loadtxt(
f.extractfile('CaliforniaHousing/cal_housing.data'),
delimiter=',')
# Columns are not in the same order compared to the previous
# URL resource on lib.stat.cmu.edu
columns_index = [8, 7, 2, 3, 4, 5, 6, 1, 0]
cal_housing = cal_housing[:, columns_index]
joblib.dump(cal_housing, filepath, compress=6)
remove(archive_path)
else:
cal_housing = joblib.load(filepath)
feature_names = ["MedInc", "HouseAge", "AveRooms", "AveBedrms",
"Population", "AveOccup", "Latitude", "Longitude"]
target, data = cal_housing[:, 0], cal_housing[:, 1:]
# avg rooms = total rooms / households
data[:, 2] /= data[:, 5]
# avg bed rooms = total bed rooms / households
data[:, 3] /= data[:, 5]
# avg occupancy = population / households
data[:, 5] = data[:, 4] / data[:, 5]
# target in units of 100,000
target = target / 100000.0
return Bunch(data=data,
target=target,
feature_names=feature_names,
DESCR=MODULE_DOCS)