CoW permute_axes #1023

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1. jturner314 commented on Jun 5, 2021

   

   jturner314

   on Jun 5, 2021

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   I think what you're asking for is already available. CowArray and ArcArray have copy-on-write behavior, and .permuted_axes() doesn't require a copy of the data, so you can just create a CowArray or ArcArray and permute its axes. Here's an example using CowArray:

   use ndarray::prelude::*;
   
   fn main() {
       let a = array![[0., 1., 2.], [3., 4., 5.]];
       assert_eq!(a.shape(), &[2, 3]);
       
       let mut b = CowArray::from(a.view()).permuted_axes([1, 0]);
       assert_eq!(b.shape(), &[3, 2]);
       assert_eq!(b, array![[0., 3.], [1., 4.], [2., 5.]]);
       
       assert!(b.is_view());
       b[[0, 0]] = 6.;
       assert!(b.is_owned());
       
       assert_eq!(a, array![[0., 1., 2.], [3., 4., 5.]]);
       assert_eq!(b, array![[6., 3.], [1., 4.], [2., 5.]]);
   }
2. jturner314

   closed this as completedon Jun 5, 2021
3. rust-ndarray

   locked and limited conversation to collaborators on Jun 5, 2021
4. jturner314

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   on Jun 5, 2021