added missing impl for multi-dim Mat::ones, Mat::zeros (issue #3756)

modules/core/src/matop.cpp

@@ -200,6 +200,7 @@ public:
     void multiply(const MatExpr& e, double s, MatExpr& res) const;
 
     static void makeExpr(MatExpr& res, int method, Size sz, int type, double alpha=1);
+    static void makeExpr(MatExpr& res, int method, int ndims, const int* sizes, int type, double alpha=1);
 };
 
 static MatOp_Initializer* getGlobalMatOpInitializer()
@@ -1555,8 +1556,13 @@ void MatOp_Initializer::assign(const MatExpr& e, Mat& m, int _type) const
 {
     if( _type == -1 )
         _type = e.a.type();
+
+    if( e.a.dims <= 2 )
         m.create(e.a.size(), _type);
-    if( e.flags == 'I' )
+    else
+        m.create(e.a.dims, e.a.size, _type);
+
+    if( e.flags == 'I' && e.a.dims <= 2 )
         setIdentity(m, Scalar(e.alpha));
     else if( e.flags == '0' )
         m = Scalar();
@@ -1577,6 +1583,12 @@ inline void MatOp_Initializer::makeExpr(MatExpr& res, int method, Size sz, int t
     res = MatExpr(getGlobalMatOpInitializer(), method, Mat(sz, type, (void*)0), Mat(), Mat(), alpha, 0);
 }
 
+inline void MatOp_Initializer::makeExpr(MatExpr& res, int method, int ndims, const int* sizes, int type, double alpha)
+{
+    res = MatExpr(getGlobalMatOpInitializer(), method, Mat(ndims, sizes, type, (void*)0), Mat(), Mat(), alpha, 0);
+}
+
+
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////
 
@@ -1636,6 +1648,20 @@ MatExpr Mat::ones(Size size, int type)
     return e;
 }
 
+MatExpr Mat::zeros(int ndims, const int* sizes, int type)
+{
+    MatExpr e;
+    MatOp_Initializer::makeExpr(e, '0', ndims, sizes, type);
+    return e;
+}
+
+MatExpr Mat::ones(int ndims, const int* sizes, int type)
+{
+    MatExpr e;
+    MatOp_Initializer::makeExpr(e, '1', ndims, sizes, type);
+    return e;
+}
+
 MatExpr Mat::eye(int rows, int cols, int type)
 {
     MatExpr e;

modules/core/test/test_mat.cpp

@@ -918,3 +918,18 @@ TEST(Core_Mat, copyNx1ToVector)
 
     ASSERT_PRED_FORMAT2(cvtest::MatComparator(0, 0), ref_dst16, cv::Mat_<ushort>(dst16));
 }
+
+TEST(Core_Mat, multiDim)
+{
+    int d[]={3,3,3};
+    Mat m0 = Mat::zeros(3,d,CV_8U);
+    ASSERT_EQ(0,sum(m0)[0]);
+    Mat m = Mat::ones(3,d,CV_8U);
+    ASSERT_EQ(27,sum(m)[0]);
+    m += 2;
+    ASSERT_EQ(81,sum(m)[0]);
+    m *= 3;
+    ASSERT_EQ(243,sum(m)[0]);
+    m += m;
+    ASSERT_EQ(486,sum(m)[0]);
+}