Added a version of clamp that can take runtime determined values.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403162

dlib/matrix/matrix_utilities.h

@@ -1773,6 +1773,43 @@ namespace dlib
         return exp(m.ref());
     }
 
+// ----------------------------------------------------------------------------------------
+
+    struct op_clamp2
+    {
+        template <typename EXP>
+        struct op : has_nondestructive_aliasing, preserves_dimensions<EXP>
+        {
+            typedef typename EXP::type type;
+            const static long cost = EXP::cost + 2;
+
+            template <typename M>
+            static type apply ( const M& m, const type& lower, const type& upper, long r, long c)
+            { 
+                const type temp = m(r,c);
+                if (temp > upper)
+                    return upper;
+                else if (temp < lower)
+                    return lower;
+                else
+                    return temp;
+            }
+        };
+    };
+
+    template <
+        typename EXP
+        >
+    const matrix_scalar_ternary_exp<EXP,typename EXP::type, op_clamp2> clamp (
+        const matrix_exp<EXP>& m,
+        const typename EXP::type& lower,
+        const typename EXP::type& upper
+    )
+    {
+        typedef matrix_scalar_ternary_exp<EXP,typename EXP::type, op_clamp2> exp;
+        return exp(m.ref(),lower, upper);
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <

dlib/matrix/matrix_utilities_abstract.h

@@ -1047,6 +1047,27 @@ namespace dlib
                         - R(r,c) == m(r,c)
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    const matrix_exp clamp (
+        const matrix_exp& m,
+        const matrix_exp::type& lower,
+        const matrix_exp::type& upper
+    );
+    /*!
+        ensures
+            - returns a matrix R such that:
+                - R::type == the same type that was in m
+                - R has the same dimensions as m
+                - for all valid r and c:
+                    - if (m(r,c) > upper) then
+                        - R(r,c) == upper
+                    - else if (m(r,c) < lower) then
+                        - R(r,c) == lower
+                    - else
+                        - R(r,c) == m(r,c)
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
 }