wehub-resource-sync
66 lines
1.4 KiB
Python
Executable File
66 lines
1.4 KiB
Python
Executable File
import numpy as np
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class LabelTransformer(object):
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"""
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Label encoder decoder
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Attributes
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----------
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n_classes : int
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number of classes, K
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"""
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def __init__(self, n_classes:int=None):
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self.n_classes = n_classes
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@property
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def n_classes(self):
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return self.__n_classes
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@n_classes.setter
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def n_classes(self, K):
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self.__n_classes = K
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self.__encoder = None if K is None else np.eye(K)
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@property
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def encoder(self):
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return self.__encoder
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def encode(self, class_indices:np.ndarray):
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"""
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encode class index into one-of-k code
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Parameters
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----------
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class_indices : (N,) np.ndarray
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non-negative class index
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elements must be integer in [0, n_classes)
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Returns
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-------
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(N, K) np.ndarray
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one-of-k encoding of input
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"""
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if self.n_classes is None:
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self.n_classes = np.max(class_indices) + 1
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return self.encoder[class_indices]
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def decode(self, onehot:np.ndarray):
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"""
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decode one-of-k code into class index
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Parameters
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----------
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onehot : (N, K) np.ndarray
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one-of-k code
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Returns
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-------
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(N,) np.ndarray
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class index
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"""
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return np.argmax(onehot, axis=1)
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