Port usage of uninitialized to build_uninit

build_uninit is necessary for abstracting over any kind of owned array. The version of take_slice_upper is still inefficient in one way (overwriting after copying), but could likely still be an improvement upon the previous version.

Author: bluss

ndarray-linalg/Cargo.toml

@@ -36,7 +36,7 @@ rand = "0.8.3"
 thiserror = "1.0.24"
 
 [dependencies.ndarray]
-version = "0.15.1"
+version = "0.15.2"
 features = ["blas", "approx", "std"]
 default-features = false
 

ndarray-linalg/src/convert.rs

@@ -46,31 +46,19 @@ where
  }
 }
 
-fn uninitialized<A, S>(l: MatrixLayout) -> ArrayBase<S, Ix2>
-where
- A: Copy,
- S: DataOwned<Elem = A>,
-{
- match l {
- MatrixLayout::C { row, lda } => unsafe {
- ArrayBase::uninitialized((row as usize, lda as usize))
- },
- MatrixLayout::F { col, lda } => unsafe {
- ArrayBase::uninitialized((lda as usize, col as usize).f())
- },
- }
-}
-
 pub fn replicate<A, Sv, So, D>(a: &ArrayBase<Sv, D>) -> ArrayBase<So, D>
 where
  A: Copy,
  Sv: Data<Elem = A>,
  So: DataOwned<Elem = A> + DataMut,
  D: Dimension,
 {
- let mut b = unsafe { ArrayBase::uninitialized(a.dim()) };
- b.assign(a);
- b
+ unsafe {
+ let ret = ArrayBase::<So, D>::build_uninit(a.dim(), |view| {
+ a.assign_to(view);
+ });
+ ret.assume_init()
+ }
 }
 
 fn clone_with_layout<A, Si, So>(l: MatrixLayout, a: &ArrayBase<Si, Ix2>) -> ArrayBase<So, Ix2>
@@ -79,9 +67,16 @@ where
  Si: Data<Elem = A>,
  So: DataOwned<Elem = A> + DataMut,
 {
- let mut b = uninitialized(l);
- b.assign(a);
- b
+ let shape_builder = match l {
+ MatrixLayout::C { row, lda } => (row as usize, lda as usize).set_f(false),
+ MatrixLayout::F { col, lda } => (lda as usize, col as usize).set_f(true),
+ };
+ unsafe {
+ let ret = ArrayBase::<So, _>::build_uninit(shape_builder, |view| {
+ a.assign_to(view);
+ });
+ ret.assume_init()
+ }
 }
 
 pub fn transpose_data<A, S>(a: &mut ArrayBase<S, Ix2>) -> Result<&mut ArrayBase<S, Ix2>>

ndarray-linalg/src/qr.rs

@@ -135,9 +135,7 @@ where
  S2: DataMut<Elem = A> + DataOwned,
 {
  let av = a.slice(s![..n as isize, ..m as isize]);
- let mut a = unsafe { ArrayBase::uninitialized((n, m)) };
- a.assign(&av);
- a
+ replicate(&av)
 }
 
 fn take_slice_upper<A, S1, S2>(a: &ArrayBase<S1, Ix2>, n: usize, m: usize) -> ArrayBase<S2, Ix2>
@@ -146,10 +144,12 @@ where
  S1: Data<Elem = A>,
  S2: DataMut<Elem = A> + DataOwned,
 {
- let av = a.slice(s![..n as isize, ..m as isize]);
- let mut a = unsafe { ArrayBase::uninitialized((n, m)) };
- for ((i, j), val) in a.indexed_iter_mut() {
- *val = if i <= j { av[(i, j)] } else { A::zero() };
- }
+ let av = a.slice(s![..n, ..m]);
+ let mut a = replicate(&av);
+ Zip::indexed(&mut a).for_each(|(i, j), elt| {
+ if i > j {
+ *elt = A::zero()
+ }
+ });
  a
 }