From 75edc549bb6c7c254070af7d4a57bdfcf0e62d5c Mon Sep 17 00:00:00 2001
From: Mathieu Blondel <mathieu@mblondel.org>
Date: Sat, 2 Nov 2019 00:55:25 +0100
Subject: [PATCH] Cosmit.

---
 polytopes.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/polytopes.py b/polytopes.py
index ee72d54..7e3c57e 100644
--- a/polytopes.py
+++ b/polytopes.py
@@ -431,13 +431,17 @@ def _Euclidean_project(self, theta):
         w = np.array(w)
         if not self.w_sorted:
             w = w[np.argsort(w)[::-1]]
+
         perm = np.argsort(theta)[::-1]
         theta = theta[perm]
-        dual_sol = isotonic_regression(w - theta, increasing=True)
-        primal_sol = dual_sol + theta
+
+        dual_sol = isotonic_regression(theta - w, increasing=False)
+
         # Or equivalently
-        #dual_sol = isotonic_regression(theta - w, increasing=False)
-        #primal_sol = theta - dual_sol
+        #dual_sol = -isotonic_regression(w - theta, increasing=True)
+
+        primal_sol = theta - dual_sol
+
         return primal_sol[inv_permutation(perm)]
 
     def _KL_project(self, theta):