iter

Author: glemaitre

imblearn/misc.py

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+"""Miscellaneous samplers objects."""
+
+# Authors: Guillaume Lemaitre <[email protected]>
+# License: MIT
+
+import logging
+
+from sklearn.utils import check_X_y
+from sklearn.utils.validation import check_is_fitted
+
+from .base import SamplerMixin
+from .utils import check_target_type, hash_X_y
+
+
+def _identity(X, y):
+    return X, y
+
+
+class FunctionSampler(SamplerMixin):
+    """Construct a sampler from calling an arbitrary callable.
+
+    Read more in the :ref:`User Guide <function_sampler>`.
+
+    Parameters
+    ----------
+    func : callable or None,
+        The callable to use for the transformation. This will be passed the
+        same arguments as transform, with args and kwargs forwarded. If func is
+        None, then func will be the identity function.
+
+    """
+
+    def __init__(self, func=None, accept_sparse=True, kw_args=None,
+                 random_state=None):
+        self.func = func
+        self.accept_sparse = accept_sparse
+        self.kw_args = kw_args
+        self.random_state = random_state
+        self.logger = logging.getLogger(__name__)
+
+    def _check_X_y(self, X, y):
+        if self.accept_sparse:
+            X, y = check_X_y(X, y, accept_sparse=['csr', 'csc'])
+        else:
+            X, y = check_X_y(X, y, accept_sparse=False)
+        y = check_target_type(y)
+
+        return X, y
+
+    def fit(self, X, y):
+        print(self.accept_sparse)
+        X, y = self._check_X_y(X, y)
+        self.X_hash_, self.y_hash_ = hash_X_y(X, y)
+        # when using a sampler, ratio_ is supposed to exist after fit
+        self.ratio_ = 'is_fitted'
+
+        return self
+
+    def _sample(self, X, y, func, kw_args):
+        X, y = self._check_X_y(X, y)
+        check_is_fitted(self, 'ratio_')
+        X_hash, y_hash = hash_X_y(X, y)
+        if self.X_hash_ != X_hash or self.y_hash_ != y_hash:
+            raise RuntimeError("X and y need to be same array earlier fitted.")
+
+        if func is None:
+            func = _identity
+
+        return func(X, y, **(kw_args if kw_args else {}))
+
+    def sample(self, X, y):
+        return self._sample(X, y, func=self.func, kw_args=self.kw_args)

imblearn/tests/test_misc.py

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+"""Test for miscellaneous samplers objects."""
+
+# Authors: Guillaume Lemaitre <[email protected]>
+# License: MIT