fix unassigned shape #406

src/TensorFlowNET.Core/Gradients/math_grad.cs

@@ -42,7 +42,8 @@ namespace Tensorflow.Gradients
             var x = op.inputs[0];
             var y = op.inputs[1];
             var grad = grads[0];
-            if (grad is Tensor && _ShapesFullySpecifiedAndEqual(x, y, grad))
+            if (grad is Tensor && 
+                _ShapesFullySpecifiedAndEqual(x, y, grad))
                 return new Tensor[] { grad, grad };
 
             var sx = array_ops.shape(x);
@@ -375,7 +376,8 @@ namespace Tensorflow.Gradients
             var grad = grads[0];
             var x = op.inputs[0];
             var y = op.inputs[1];
-            if (grad is Tensor && _ShapesFullySpecifiedAndEqual(x, y, grad))
+            if (grad is Tensor && 
+                _ShapesFullySpecifiedAndEqual(x, y, grad))
                 return new Tensor[] { grad, -grad };
 
             var sx = array_ops.shape(x);

src/TensorFlowNET.Core/Tensors/Tensor.cs

@@ -132,10 +132,10 @@ namespace Tensorflow
 
         public int[] _shape_tuple()
         {
-            return NDims < 0 ? null : shape;
+            return rank < 0 ? null : shape;
         }
 
-        public TensorShape TensorShape => tensor_util.to_shape(shape);
+        public TensorShape TensorShape => rank < 0 ? new TensorShape() : tensor_util.to_shape(shape);
 
         /// <summary>
         ///     Updates the shape of this tensor.
@@ -165,6 +165,7 @@ namespace Tensorflow
 
         /// <summary>
         /// number of dimensions <br></br>
+        /// -1 Unknown  <br></br>
         /// 0	Scalar (magnitude only) <br></br>
         /// 1	Vector (magnitude and direction) <br></br>
         /// 2	Matrix (table of numbers) <br></br>
@@ -178,11 +179,13 @@ namespace Tensorflow
             {
                 if (_handle == IntPtr.Zero)
                 {
-                    var status = new Status();
-                    var output = _as_tf_output();
-                    int ndim = c_api.TF_GraphGetTensorNumDims(op.graph, output, status);
-                    status.Check();
-                    return ndim;
+                    using (var status = new Status())
+                    {
+                        var output = _as_tf_output();
+                        int ndim = c_api.TF_GraphGetTensorNumDims(op.graph, output, status);
+                        status.Check();
+                        return ndim;
+                    }
                 }
 
                 return c_api.TF_NumDims(_handle);
@@ -440,16 +443,15 @@ namespace Tensorflow
         public override string ToString()
         {
             // this can throw IndexOutOfRangeException 
-            //if(NDims == 0)
-            //{
-            //    switch (dtype)
-            //    {
-            //        case TF_DataType.TF_INT32:
-            //            return Data<int>()[0].ToString();
-            //    }
-            //}
-
-            return $"tf.Tensor '{name}' shape=({string.Join(",", shape)}) dtype={dtype}";
+            switch (rank)
+            {
+                case -1:
+                    return $"tf.Tensor '{name}' shape=<unknown> dtype={dtype}";
+                case 0:
+                    return $"tf.Tensor '{name}' shape=() dtype={dtype}";
+                default:
+                    return $"tf.Tensor '{name}' shape=({string.Join(",", shape)}) dtype={dtype}";
+            }
         }
 
         /// <summary>

src/TensorFlowNET.Core/Tensors/TensorShape.cs

@@ -24,12 +24,13 @@ namespace Tensorflow
         /// <summary>
         ///     Returns the rank of this shape.
         /// </summary>
-        public int ndim => shape.NDim;
+        public int ndim => rank;
 
+        private int _rank;
         /// <summary>
         ///     Returns the rank of this shape.
         /// </summary>
-        public int rank => shape.NDim;
+        public int rank => _rank > -1 ? shape.NDim : -1;
 
         /// <summary>
         ///     Returns the size this shape represents.
@@ -52,6 +53,12 @@ namespace Tensorflow
             }
         }
 
+        public TensorShape()
+        {
+            _rank = -1;
+            shape = new Shape();
+        }
+
         public TensorShape(TensorShapeProto proto)
         {
             if (proto.UnknownRank) return;
@@ -77,7 +84,7 @@ namespace Tensorflow
             switch (dims.Length)
             {
                 case 0: shape = new Shape(new int[0]); break;
-                case 1: shape = Shape.Vector((int)dims[0]); break;
+                case 1: shape = Shape.Vector(dims[0]); break;
                 case 2: shape = Shape.Matrix(dims[0], dims[1]); break;
                 default: shape = new Shape(dims); break;
             }
@@ -127,7 +134,7 @@ namespace Tensorflow
         /// <returns></returns>
         public bool is_fully_defined()
         {
-            return dims != null && dims.Count(x => x < 1) == 0;
+            return rank > -1 && dims != null && dims.Count(x => x < 1) == 0;
         }
 
         public bool is_compatible_with(TensorShape shape2)
@@ -204,7 +211,7 @@ namespace Tensorflow
         /// <returns></returns>
         public TensorShape merge_with(TensorShape other)
         {
-            if (dims.Length == 0)
+            if (dims == null)
                 return other;
 
             var new_dims = new List<int>();

test/TensorFlowNET.UnitTest/TensorShapeTest.cs

@@ -56,5 +56,12 @@ namespace TensorFlowNET.UnitTest
             TensorShape shape = (Unknown, 1, 2, 3, Unknown);
             shape.GetPrivate<Shape>("shape").Should().BeShaped(-1, 1, 2, 3, -1);
         }
+
+        [TestMethod]
+        public void Case7()
+        {
+            TensorShape shape = new TensorShape();
+            Assert.AreEqual(shape.rank, -1);
+        }
     }
 }