Revision - cc74d24 - Inplace transpose for unit Triangular may skip diagonal (#53101) - origin: https://github.com/JuliaLang/julia

visit type:

https://github.com/JuliaLang/julia

19 April 2024, 06:28:37 UTC

Revision cc74d241be9f023ceb6d2ded7314bfbd02f8b17c authored by Jishnu Bhattacharya on 31 January 2024, 12:09:57 UTC, committed by GitHub on 31 January 2024, 12:09:57 UTC

Inplace transpose for unit Triangular may skip diagonal (#53101)

Since the diagonal elements of a `UnitUpperTriangular` are given by
`onelement`, these should be unchanged under `transpose/adjoint`, and we
don't need to access these elements in the parent array when performing
in-place operations.

Fixes
```julia
julia> using LinearAlgebra

julia> M = Matrix{BigFloat}(undef, 2, 2);

julia> M[1,2] = 3;

julia> U = UnitUpperTriangular(M)
2×2 UnitUpperTriangular{BigFloat, Matrix{BigFloat}}:
 1.0  3.0
  ⋅   1.0

julia> transpose!(U)
ERROR: UndefRefError: access to undefined reference
Stacktrace:
 [1] getindex
   @ ./essentials.jl:882 [inlined]
 [2] getindex
   @ ./array.jl:915 [inlined]
 [3] copytri!
   @ ~/packages/julias/julia-latest/share/julia/stdlib/v1.11/LinearAlgebra/src/matmul.jl:414 [inlined]
 [4] transpose!(A::UnitUpperTriangular{BigFloat, Matrix{BigFloat}})
   @ LinearAlgebra ~/packages/julias/julia-latest/share/julia/stdlib/v1.11/LinearAlgebra/src/triangular.jl:470
 [5] top-level scope
   @ REPL[5]:1
```
After this PR:
```julia
julia> transpose!(U)
2×2 UnitLowerTriangular{BigFloat, Matrix{BigFloat}}:
 1.0   ⋅ 
 3.0  1.0
```

1 parent cb9b00d

Files
Changes

Permalinks

Tip revision: cc74d241be9f023ceb6d2ded7314bfbd02f8b17c authored by Jishnu Bhattacharya on 31 January 2024, 12:09:57 UTC
Inplace transpose for unit Triangular may skip diagonal (#53101)

Tip revision: cc74d24

File	Mode	Size
.devcontainer
.github
base
cli
contrib
deps
doc
etc
src
stdlib
test
.buildkite-external-version	-rw-r--r--	5 bytes
.clang-format	-rw-r--r--	3.3 KB
.clangd	-rw-r--r--	114 bytes
.codecov.yml	-rw-r--r--	52 bytes
.git-blame-ignore-revs	-rw-r--r--	371 bytes
.gitattributes	-rw-r--r--	65 bytes
.gitignore	-rw-r--r--	523 bytes
.mailmap	-rw-r--r--	12.7 KB
CITATION.bib	-rw-r--r--	513 bytes
CITATION.cff	-rw-r--r--	940 bytes
CONTRIBUTING.md	-rw-r--r--	23.4 KB
HISTORY.md	-rw-r--r--	372.8 KB
LICENSE.md	-rw-r--r--	1.3 KB
Make.inc	-rw-r--r--	55.9 KB
Makefile	-rw-r--r--	30.2 KB
NEWS.md	-rw-r--r--	10.6 KB
README.md	-rw-r--r--	7.4 KB
THIRDPARTY.md	-rw-r--r--	3.9 KB
VERSION	-rw-r--r--	11 bytes
julia.spdx.json	-rw-r--r--	37.8 KB
pkgimage.mk	-rw-r--r--	5.8 KB
sysimage.mk	-rw-r--r--	4.2 KB
typos.toml	-rw-r--r--	78 bytes

Showing with 0 additions and 0 deletions (0 / 0 diffs computed)

Computing file changes ...

https://github.com/JuliaLang/julia

Inplace transpose for unit Triangular may skip diagonal (#53101)

README.md