Fix error in the sigmoid function (#145)

Change sigmoid function from 1 / (1 + np.exp(x)) to 1 / (1 + np.exp(-x)) TODO: Make patch release v.0.2.1
ljvmiranda921 · Jun 26, 2018 · 18ccecc · 18ccecc
1 parent 094e2ef
commit 18ccecc
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/pyswarms/discrete/binary.py b/pyswarms/discrete/binary.py
@@ -219,5 +219,5 @@ def _sigmoid(self, x):
         numpy.ndarray
             Output sigmoid computation
         """
-        return 1 / (1 + np.exp(x))
+        return 1 / (1 + np.exp(-x))