Default.Reduce*: Proper handling when empty array or scalar

Nucs · Nucs · commit c60920b04f54 · 2019-08-07T17:15:17.000+03:00
diff --git a/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.CumAdd.cs b/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.CumAdd.cs
@@ -16,12 +16,7 @@ public override unsafe NDArray ReduceCumAdd(in NDArray arr, int? axis_, NPTypeCo
                 return arr;
 
             if (shape.IsScalar || shape.size == 1 && shape.dimensions.Length == 1)
-            {
-                var r = typeCode.HasValue ? Cast(arr, typeCode.Value, true) : arr.Clone();
-                if (!r.Shape.IsScalar && r.Shape.size == 1 && r.ndim == 1)
-                    r.Storage.Reshape(Shape.Scalar);
-                return r;
-            }
+                return typeCode.HasValue ? Cast(arr, typeCode.Value, copy: true) : arr.Clone();
 
             if (axis_ == null)
             {
diff --git a/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.Mean.cs b/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.Mean.cs
@@ -17,11 +17,9 @@ public override NDArray ReduceMean(in NDArray arr, int? axis_, bool keepdims = f
 
             if (shape.IsScalar || (shape.size == 1 && shape.NDim == 1))
             {
-                var r = typeCode.HasValue ? Cast(arr, typeCode.Value, true) : arr.Clone();
+                var r = NDArray.Scalar(typeCode.HasValue ? Converts.ChangeType(arr.GetAtIndex(0), typeCode.Value) : arr.GetAtIndex(0));
                 if (keepdims)
                     r.Storage.ExpandDimension(0);
-                else if (!r.Shape.IsScalar && r.Shape.size == 1 && r.ndim == 1)
-                    r.Storage.Reshape(Shape.Scalar);
                 return r;
             }
 
diff --git a/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.Product.cs b/src/NumSharp.Core/Backends/Default/Math/Reduction/Default.Reduction.Product.cs
@@ -12,19 +12,15 @@ public override NDArray ReduceProduct(NDArray arr, int? axis_, bool keepdims = f
             //the size of the array is [1, 2, n, m] all shapes after 2nd multiplied gives size
             //the size of what we need to reduce is the size of the shape of the given axis (shape[axis])
             var shape = arr.Shape;
-            if (shape.IsEmpty)
-                return arr;
+            if (shape.IsEmpty || shape.size==0)
+                return NDArray.Scalar(1, (typeCode ?? arr.typecode));
 
-            if (shape.IsScalar || (shape.size <= 1 && shape.NDim == 1))
+            if (shape.IsScalar || (shape.size == 1 && shape.NDim == 1))
             {
-                var r = typeCode.HasValue ? Cast(arr, typeCode.Value, true) : arr.Clone();
+                var r = NDArray.Scalar(typeCode.HasValue ? Converts.ChangeType(arr.GetAtIndex(0), typeCode.Value) : arr.GetAtIndex(0));
                 if (keepdims)
                     r.Storage.ExpandDimension(0);
-                else if (!r.Shape.IsScalar && r.Shape.size == 1 && r.ndim == 1)
-                    r.Storage.Reshape(Shape.Scalar);
-                else if (!r.Shape.IsScalar && r.Shape.size == 0 && r.ndim == 1)
-                    return NDArray.Scalar(1, arr.typecode);
-
+                
                 return r;
             }
 

Original file line number	Diff line number	Diff line change
`@@ -17,11 +17,9 @@ public override NDArray ReduceMean(in NDArray arr, int? axis_, bool keepdims = f`
`17`	`17`
`18`	`18`	`if (shape.IsScalar \|\| (shape.size == 1 && shape.NDim == 1))`
`19`	`19`	`{`
`20`		`- var r = typeCode.HasValue ? Cast(arr, typeCode.Value, true) : arr.Clone();`
	`20`	`+ var r = NDArray.Scalar(typeCode.HasValue ? Converts.ChangeType(arr.GetAtIndex(0), typeCode.Value) : arr.GetAtIndex(0));`
`21`	`21`	`if (keepdims)`
`22`	`22`	`r.Storage.ExpandDimension(0);`
`23`		`- else if (!r.Shape.IsScalar && r.Shape.size == 1 && r.ndim == 1)`
`24`		`- r.Storage.Reshape(Shape.Scalar);`
`25`	`23`	`return r;`
`26`	`24`	`}`
`27`	`25`