added optional output for explained

alphamind/data/neutralize.py

@@ -6,14 +6,19 @@ Created on 2017-4-25
 """
 
 import numpy as np
+from numpy import zeros
 from numpy.linalg import solve
 from typing import Tuple
+from typing import Union
 from alphamind.aggregate import groupby
 
 
-def neutralize(x: np.ndarray, y: np.ndarray, groups: np.ndarray=None) -> Tuple[np.ndarray, np.ndarray]:
+def neutralize(x: np.ndarray, y: np.ndarray, groups: np.ndarray=None, keep_explained=False) \
+        -> Union[np.ndarray, Tuple[np.ndarray, np.ndarray]]:
     if groups is not None:
-        res = np.zeros(y.shape)
+        res = zeros(y.shape)
+        if keep_explained:
+            explained = zeros((x.shape[1],) + y.shape)
         groups_ids = groupby(groups)
 
         for curr_idx in groups_ids:
@@ -21,10 +26,18 @@ def neutralize(x: np.ndarray, y: np.ndarray, groups: np.ndarray=None) -> Tuple[n
             curr_y = y[curr_idx]
             b = ls_fit(x[curr_idx], y[curr_idx])
             res[curr_idx] = ls_res(curr_x, curr_y, b)
-        return res
+            if keep_explained:
+                explained[curr_idx] = ls_explain(curr_x, curr_y, b)
+        if keep_explained:
+            return res, explained
+        else:
+            return res
     else:
         b = ls_fit(x, y)
-        return ls_res(x, y, b)
+        if keep_explained:
+            return ls_res(x, y, b), ls_explain(x, y, b)
+        else:
+            return ls_res(x, y, b)
 
 
 def ls_fit(x: np.ndarray, y: np.ndarray) -> np.ndarray:
@@ -37,8 +50,19 @@ def ls_res(x: np.ndarray, y: np.ndarray, b: np.ndarray) -> np.ndarray:
     return y - x @ b
 
 
-def ls_explained(x: np.ndarray, y: np.ndarray, b: np.ndarray) -> np.ndarray:
-    pass
+def ls_explain(x: np.ndarray, y: np.ndarray, b: np.ndarray) -> np.ndarray:
+    if y.ndim == 1:
+        return y.reshape((-1, 1)) - b * x
+    else:
+        n_samples = y.shape[0]
+        dependends = y.shape[1]
+        factors = x.shape[1]
+        explained = zeros((n_samples, factors, dependends))
+
+        for i in range(dependends):
+            this_y = y[:, [i]]
+            explained[:, :, i] = this_y - b[:, i] * x
+        return explained
 
 
 if __name__ == '__main__':

alphamind/tests/data/test_neutralize.py

@@ -40,7 +40,9 @@ class TestNeutralize(unittest.TestCase):
             curr_y = y[groups == i]
             model.fit(curr_x, curr_y)
             exp_res = curr_y - curr_x @ model.coef_.T
-            np.testing.assert_array_almost_equal(calc_res[groups ==i ], exp_res)
+            np.testing.assert_array_almost_equal(calc_res[groups ==i
+
+                                                 ], exp_res)
 
 
 if __name__ == '__main__':