class QDA(object):
def __init__(self,
priors=None,
reg_param=0.,
store_covariance=False,
tol=1.0e-4):
"""
:param priors: 分来优先级， array, 可选项， shape=[n_classes]
:param reg_param: float, 可选项，将协方差估计正规化
:param store_covariance: boolean 如果为真，则计算并存储协方差矩阵到self.covariance_中
:param tol: 使用排序评估的阈值
"""
self.model = QuadraticDiscriminantAnalysis(
priors=priors,
reg_param=reg_param,
store_covariance=store_covariance,
tol=tol)
def fit(self, x, y):
self.model.fit(X=x, y=y)
def get_params(self, deep=True):
return self.model.get_params(deep=deep)
def predict(self, x):
return self.model.predict(X=x)
def predict_log_dict(self, x):
return self.model.predict_log_proba(X=x)
def predict_proba(self, x):
return self.model.predict_proba(X=x)
def score(self, x, y, sample_weight=None):
return self.model.score(X=x, y=y, sample_weight=sample_weight)
def set_params(self, **params):
self.model.set_params(**params)
def decision_function(self, x): # 将决策函数应用于样本数组。
return self.model.decision_function(X=x)
def get_attribute(self):
covariance = self.model.covariance_ # 每个种类的协方差矩阵， list of array-like of shape (n_features, n_features)
means = self.model.means # 种类均值， array-like of shape (n_classes, n_features)
priors = self.model.priors_ # 种类占比， 求和为1， array-like of shape (n_classes)
rotations = self.model.rotations_ # n_k = min(n_features, number of elements in class k) list_array,
# 高斯分布的旋转
scalings = self.model.scalings_ # list_array, 每个种类k，shape[n_k]的数组，包含高斯分布的缩放，
# 如，旋转坐标系中的方差
classes = self.model.classes_ # array-like, shape(n_classes,), 不同种类标签
return covariance, means, priors, rotations, scalings, classes
class QuadraticDiscriminantAnalysis(Classifier):
r"""Implementation of quadratic discriminant analysis classifier.
Date:
2020
Author:
Luka Pečnik
License:
MIT
Reference:
“The Elements of Statistical Learning”, Hastie T., Tibshirani R., Friedman J., Section 4.3, p.106-119, 2008.
Documentation:
https://scikit-learn.org/stable/modules/generated/sklearn.discriminant_analysis.QuadraticDiscriminantAnalysis.html#sklearn.discriminant_analysis.QuadraticDiscriminantAnalysis
See Also:
* :class:`niaaml.classifiers.Classifier`
"""
Name = 'Quadratic Discriminant Analysis'
def __init__(self, **kwargs):
r"""Initialize QuadraticDiscriminantAnalysis instance.
"""
warnings.filterwarnings(action='ignore', category=ChangedBehaviorWarning)
warnings.filterwarnings(action='ignore', category=ConvergenceWarning)
warnings.filterwarnings(action='ignore', category=DataConversionWarning)
warnings.filterwarnings(action='ignore', category=DataDimensionalityWarning)
warnings.filterwarnings(action='ignore', category=EfficiencyWarning)
warnings.filterwarnings(action='ignore', category=FitFailedWarning)
warnings.filterwarnings(action='ignore', category=NonBLASDotWarning)
warnings.filterwarnings(action='ignore', category=UndefinedMetricWarning)
self.__qda = QDA()
super(QuadraticDiscriminantAnalysis, self).__init__()
def set_parameters(self, **kwargs):
r"""Set the parameters/arguments of the algorithm.
"""
self.__qda.set_params(**kwargs)
def fit(self, x, y, **kwargs):
r"""Fit QuadraticDiscriminantAnalysis.
Arguments:
x (pandas.core.frame.DataFrame): n samples to classify.
y (pandas.core.series.Series): n classes of the samples in the x array.
Returns:
None
"""
self.__qda.fit(x, y)
def predict(self, x, **kwargs):
r"""Predict class for each sample (row) in x.
Arguments:
x (pandas.core.frame.DataFrame): n samples to classify.
Returns:
pandas.core.series.Series: n predicted classes.
"""
return self.__qda.predict(x)
def to_string(self):
r"""User friendly representation of the object.
Returns:
str: User friendly representation of the object.
"""
return Classifier.to_string(self).format(name=self.Name, args=self._parameters_to_string(self.__qda.get_params()))
