FIX: bug in elasticnet with precompute not being updated correctly.

Fabian Pedregosa · Fabian Pedregosa · commit f97734698902 · 2012-01-09T16:12:55.000+01:00
And added a remark on updating the Gram matrix. This was triggered by
tests inside dict_learning, probably the last commit made this
visible. Thus I'm not adding more tests.
diff --git a/sklearn/linear_model/coordinate_descent.py b/sklearn/linear_model/coordinate_descent.py
@@ -130,7 +130,10 @@ def fit(self, X, y, Xy=None, coef_init=None):
                 self.fit_intercept, self.normalize, copy=self.copy_X)
         precompute = self.precompute
         if X_init is not X and hasattr(precompute, '__array__'):
-            precompute = 'auto'  # recompute Gram
+            # recompute Gram
+            # FIXME: it could be updated from precompute and X_mean
+            # instead of recomputed
+            precompute = 'auto'
         if X_init is not X and Xy is not None:
             Xy = None  # recompute Xy
 
@@ -145,7 +148,7 @@ def fit(self, X, y, Xy=None, coef_init=None):
         X = np.asfortranarray(X)  # make data contiguous in memory
 
         # precompute if n_samples > n_features
-        if hasattr(self.precompute, '__array__'):
+        if hasattr(precompute, '__array__'):
             Gram = precompute
         elif precompute == True or \
                (precompute == 'auto' and n_samples > n_features):
