DOC: updating GridSearchCV's n_jobs parameter

accraze · accraze · commit c2e48e01c89f · 2017-01-03T20:34:26.000-08:00
fixes #5797
diff --git a/sklearn/grid_search.py b/sklearn/grid_search.py
@@ -670,8 +670,16 @@ class GridSearchCV(BaseSearchCV):
     fit_params : dict, optional
         Parameters to pass to the fit method.
 
-    n_jobs : int, default=1
-        Number of jobs to run in parallel.
+    n_jobs: int, default: 1 :
+        The maximum number of estimators fit in parallel.
+
+            - If -1 all CPUs are used.
+
+            - If 1 is given, no parallel computing code is used at all,
+              which is useful for debugging.
+
+            - For ``n_jobs`` below -1, ``(n_cpus + n_jobs + 1)`` are used.
+              For example, with ``n_jobs = -2`` all CPUs but one are used.
 
         .. versionchanged:: 0.17
            Upgraded to joblib 0.9.3.
@@ -888,8 +896,16 @@ class RandomizedSearchCV(BaseSearchCV):
     fit_params : dict, optional
         Parameters to pass to the fit method.
 
-    n_jobs : int, default=1
-        Number of jobs to run in parallel.
+    n_jobs: int, default: 1 :
+        The maximum number of estimators fit in parallel.
+
+            - If -1 all CPUs are used.
+
+            - If 1 is given, no parallel computing code is used at all,
+              which is useful for debugging.
+
+            - For ``n_jobs`` below -1, ``(n_cpus + n_jobs + 1)`` are used.
+              For example, with ``n_jobs = -2`` all CPUs but one are used.
 
     pre_dispatch : int, or string, optional
         Controls the number of jobs that get dispatched during parallel
@@ -1027,3 +1043,4 @@ def fit(self, X, y=None):
                                           self.n_iter,
                                           random_state=self.random_state)
         return self._fit(X, y, sampled_params)
+
