Added is_finite() for matrix objects.

dlib/algs.h

@@ -451,26 +451,6 @@ namespace dlib
     template <> struct is_float_type<double>      { const static bool value = true; };
     template <> struct is_float_type<long double> { const static bool value = true; };
 
-// ----------------------------------------------------------------------------------------
-
-    template <
-        typename T
-        >
-    bool is_finite (
-        const T& value
-    )
-    /*!
-        ensures
-            - returns true if value is a finite value (e.g. not infinity or NaN) and false
-              otherwise.
-    !*/
-    {
-        if (is_float_type<T>::value)
-            return -std::numeric_limits<T>::infinity() < value && value < std::numeric_limits<T>::infinity();
-        else
-            return true;
-    }
-
 // ----------------------------------------------------------------------------------------
 
     /*!A is_convertible
@@ -650,6 +630,28 @@ namespace dlib
     template <> struct is_built_in_scalar_type<wchar_t>         { const static bool value = true; };
 #endif
 
+// ----------------------------------------------------------------------------------------
+    
+    template <
+        typename T
+        >
+    typename enable_if<is_built_in_scalar_type<T>,bool>::type is_finite (
+        const T& value
+    )
+    /*!
+        requires
+            - value must be some kind of scalar type such as int or double
+        ensures
+            - returns true if value is a finite value (e.g. not infinity or NaN) and false
+              otherwise.
+    !*/
+    {
+        if (is_float_type<T>::value)
+            return -std::numeric_limits<T>::infinity() < value && value < std::numeric_limits<T>::infinity();
+        else
+            return true;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     /*!A promote 

dlib/matrix/matrix_utilities.h

@@ -63,6 +63,24 @@ namespace dlib
         const matrix_exp<EXP>& m
     ) { return is_row_vector(m) || is_col_vector(m); }
 
+// ----------------------------------------------------------------------------------------
+
+    template <typename EXP>
+    inline bool is_finite (
+        const matrix_exp<EXP>& m
+    ) 
+    { 
+        for (long r = 0; r < m.nr(); ++r)
+        {
+            for (long c = 0; c < m.nc(); ++c)
+            {
+                if (!is_finite(m(r,c)))
+                    return false;
+            }
+        }
+        return true;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     namespace impl

dlib/matrix/matrix_utilities_abstract.h

@@ -1041,6 +1041,17 @@ namespace dlib
                 - returns false
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    bool is_finite (
+        const matrix_exp& m
+    );
+    /*!
+        ensures
+            - returns true if all the values in m are finite values and also not any kind
+              of NaN value.
+    !*/
+
 // ----------------------------------------------------------------------------------------
 // ----------------------------------------------------------------------------------------
 //                      Thresholding relational operators 

dlib/test/matrix.cpp

@@ -1208,6 +1208,7 @@ namespace
             m1 = 1;
             m2 = 1;
             m1 = m1*subm(m2,0,0,3,3);
+            DLIB_TEST(is_finite(m1));
         }
         {
             matrix<double,3,1> m1;
@@ -1253,7 +1254,21 @@ namespace
 
             DLIB_TEST(m(0) == 6);
             DLIB_TEST(m(1) == 6);
+            DLIB_TEST(is_finite(m));
         }
+
+
+        {
+            matrix<double> m(3,3);
+            m = 3;
+            m(1,1) = std::numeric_limits<double>::infinity();
+            DLIB_TEST(is_finite(m) == false);
+            m(1,1) = -std::numeric_limits<double>::infinity();
+            DLIB_TEST(is_finite(m) == false);
+            m(1,1) = 2;
+            DLIB_TEST(is_finite(m));
+        }
+
     }