use view().into_dimensionality() instead

Author: SparrowLii

benches/bench1.rs

@@ -11,7 +11,7 @@ extern crate test;
 
 use std::mem::MaybeUninit;
 
-use ndarray::ShapeBuilder;
+use ndarray::{ShapeBuilder, Array3, Array4};
 use ndarray::{arr0, arr1, arr2, azip, s};
 use ndarray::{Array, Array1, Array2, Axis, Ix, Zip};
 use ndarray::{Ix1, Ix2, Ix3, Ix5, IxDyn};
@@ -998,3 +998,21 @@ fn into_dyn_dyn(bench: &mut test::Bencher) {
     let a = a.view();
     bench.iter(|| a.clone().into_dyn());
 }
+
+#[bench]
+fn broadcast_same_dim(bench: &mut test::Bencher) {
+    let s = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
+    let s = Array4::from_shape_vec((2, 2, 3, 2), s.to_vec()).unwrap();
+    let a = s.slice(s![.., ..;-1, ..;2, ..]);
+    let b = s.slice(s![.., .., ..;2, ..]);
+    bench.iter(|| &a + &b);
+}
+
+#[bench]
+fn broadcast_one_side(bench: &mut test::Bencher) {
+    let s = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
+    let s2 = [1 ,2 ,3 ,4 ,5 ,6];
+    let a = Array4::from_shape_vec((4, 1, 3, 2), s.to_vec()).unwrap();
+    let b = Array3::from_shape_vec((1, 3, 2), s2.to_vec()).unwrap();
+    bench.iter(|| &a + &b);
+}

src/impl_methods.rs

@@ -1805,35 +1805,20 @@ where
     {
         let shape = co_broadcast::<D, E, <D as DimMax<E>>::Output>(&self.dim, &other.dim)?;
         let view1 = if shape.slice() == self.dim.slice() {
-            self.to_dimensionality::<<D as DimMax<E>>::Output>()
+            self.view().into_dimensionality::<<D as DimMax<E>>::Output>().unwrap()
+        } else if let Some(view1) = self.broadcast(shape.clone()) {
+            view1
         } else {
-            self.broadcast(shape.clone())
+            return Err(from_kind(ErrorKind::IncompatibleShape))
         };
         let view2 = if shape.slice() == other.dim.slice() {
-            other.to_dimensionality::<<D as DimMax<E>>::Output>()
+            other.view().into_dimensionality::<<D as DimMax<E>>::Output>().unwrap()
+        } else if let Some(view2) = other.broadcast(shape) {
+            view2
         } else {
-            other.broadcast(shape)
+            return Err(from_kind(ErrorKind::IncompatibleShape))
         };
-        if let Some(view1) = view1 {
-            if let Some(view2) = view2 {
-                return Ok((view1, view2));
-            }
-        }
-        Err(from_kind(ErrorKind::IncompatibleShape))
-    }
-
-    /// Creat an array view from an array with the same shape, but different dimensionality
-    /// type. Return None if the numbers of axes mismatch.
-    #[inline]
-    pub(crate) fn to_dimensionality<D2>(&self) -> Option<ArrayView<'_, A, D2>>
-    where
-        D2: Dimension,
-        S: Data,
-    {
-        let dim = <D2>::from_dimension(&self.dim)?;
-        let strides = <D2>::from_dimension(&self.strides)?;
-
-        unsafe { Some(ArrayView::new(self.ptr, dim, strides)) }
+        Ok((view1, view2))
     }
 
     /// Swap axes `ax` and `bx`.

src/impl_ops.rs

@@ -180,8 +180,8 @@ where
     type Output = Array<A, <D as DimMax<E>>::Output>;
     fn $mth(self, rhs: &'a ArrayBase<S2, E>) -> Self::Output {
         let (lhs, rhs) = if self.ndim() == rhs.ndim() && self.shape() == rhs.shape() {
-            let lhs = self.to_dimensionality::<<D as DimMax<E>>::Output>().unwrap();
-            let rhs = rhs.to_dimensionality::<<D as DimMax<E>>::Output>().unwrap();
+            let lhs = self.view().into_dimensionality::<<D as DimMax<E>>::Output>().unwrap();
+            let rhs = rhs.view().into_dimensionality::<<D as DimMax<E>>::Output>().unwrap();
             (lhs, rhs)
         } else {
             self.broadcast_with(rhs).unwrap()