From 6ca45db06eead31a9920364f0d47c0a51bf8a96a Mon Sep 17 00:00:00 2001
From: Davis King <davis@dlib.net>
Date: Sun, 7 Dec 2014 11:00:11 -0500
Subject: [PATCH] Added max_point()

---
 dlib/matrix/matrix_utilities.h          | 35 +++++++++++++++++++++++++
 dlib/matrix/matrix_utilities_abstract.h | 13 +++++++++
 2 files changed, 48 insertions(+)

diff --git a/dlib/matrix/matrix_utilities.h b/dlib/matrix/matrix_utilities.h
index e9c328e0d..5e61f4ecf 100644
--- a/dlib/matrix/matrix_utilities.h
+++ b/dlib/matrix/matrix_utilities.h
@@ -122,6 +122,41 @@ namespace dlib
         }
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename EXP
+        >
+    point max_point (
+        const matrix_exp<EXP>& m
+    )
+    {
+        DLIB_ASSERT(m.size() > 0, 
+            "\tpoint max_point(const matrix_exp& m)"
+            << "\n\tm can't be empty"
+            << "\n\tm.size():   " << m.size() 
+            << "\n\tm.nr():     " << m.nr() 
+            << "\n\tm.nc():     " << m.nc() 
+            );
+        typedef typename matrix_exp<EXP>::type type;
+
+        point best_point(0,0);
+        type val = m(0,0);
+        for (long r = 0; r < m.nr(); ++r)
+        {
+            for (long c = 0; c < m.nc(); ++c)
+            {
+                type temp = m(r,c);
+                if (dlib::impl::magnitude(temp) > dlib::impl::magnitude(val))
+                {
+                    val = temp;
+                    best_point = point(c,r);
+                }
+            }
+        }
+        return best_point;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <
diff --git a/dlib/matrix/matrix_utilities_abstract.h b/dlib/matrix/matrix_utilities_abstract.h
index cd02c03d2..e5d62f566 100644
--- a/dlib/matrix/matrix_utilities_abstract.h
+++ b/dlib/matrix/matrix_utilities_abstract.h
@@ -1409,6 +1409,19 @@ namespace dlib
               (i.e. m(index_of_min(m)) == min(m))
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    point max_point (
+        const matrix_exp& m
+    );
+    /*!
+        requires
+            - m.size() > 0
+        ensures
+            - returns the location of the maximum element of the array, that is, if the
+              returned point is P then it will be the case that: m(P.y(),P.x()) == max(m).
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     const matrix_exp::type sum (