add numpy api of np.moveaxis #891

Author: Oceania2018

src/TensorFlowNET.Core/NumPy/Numpy.Manipulation.cs

@@ -25,5 +25,8 @@ public partial class np
 
         [AutoNumPy]
         public static NDArray stack(params NDArray[] arrays) => new NDArray(array_ops.stack(arrays));
+
+        [AutoNumPy]
+        public static NDArray moveaxis(NDArray array, Axis source, Axis destination) => new NDArray(array_ops.moveaxis(array, source, destination));
     }
 }

src/TensorFlowNET.Core/Operations/array_ops.cs

@@ -792,6 +792,26 @@ public static Tensor[] meshgrid<T>(T[] array, bool copy = true, bool sparse = fa
             });
         }
 
+        public static Tensor moveaxis(NDArray array, Axis source, Axis destination)
+        {
+            List<int> perm = null;
+            source = source.axis.Select(x => x < 0 ? array.rank + x : x).ToArray();
+            destination = destination.axis.Select(x => x < 0 ? array.rank + x : x).ToArray();
+
+            if (array.shape.rank > -1)
+            {
+                perm = range(0, array.rank).Where(i => !source.axis.Contains(i)).ToList();
+                foreach (var (dest, src) in zip(destination.axis, source.axis).OrderBy(x => x.Item1))
+                {
+                    perm.Insert(dest, src);
+                }
+            }
+            else
+                throw new NotImplementedException("");
+
+            return array_ops.transpose(array, perm.ToArray());
+        }
+
         /// <summary>
         /// Computes the shape of a broadcast given symbolic shapes.
         /// When shape_x and shape_y are Tensors representing shapes(i.e.the result of

test/TensorFlowNET.UnitTest/NumPy/Manipulation.Test.cs

@@ -24,5 +24,19 @@ public void expand_dims()
             y = np.expand_dims(x, axis: 1);
             Assert.AreEqual(y.shape, (2, 1));
         }
+
+        [TestMethod]
+        public void moveaxis()
+        {
+            var x = np.zeros((3, 4, 5));
+            var y = np.moveaxis(x, 0, -1);
+            Assert.AreEqual(y.shape, (4, 5, 3));
+
+            y = np.moveaxis(x, (0, 1), (-1, -2));
+            Assert.AreEqual(y.shape, (5, 4, 3));
+
+            y = np.moveaxis(x, (0, 1, 2), (-1, -2, -3));
+            Assert.AreEqual(y.shape, (5, 4, 3));
+        }
     }
 }