Ben Gear (May 12 2021 at 21:44): Ben Gear (May 12 2021 at 21:44):Just a quick one. Is there a quicker (as in fewer characters) way to get the transpose of a matrix, other than just typing transpose(A)?
David Weingut (May 12 2021 at 21:45):there is A', which I think is identical
Ben Gear (May 12 2021 at 21:46):I thought that was the conjugate transpose? Similar to Matlab
Mason Protter (May 12 2021 at 21:49):' is the conjugate transpose.
David Weingut (May 12 2021 at 21:50):Yeah, you're right, sorry. Realized that I was using A' like transpose(A)...
Mason Protter (May 12 2021 at 21:51):There's a couple options. One would be to write:
julia> struct ᵀ end; Base.:(*)(A, ::Type{ᵀ}) = transpose(A)
julia> A = [1 2; 3 4]
2×2 Matrix{Int64}:
1 2
3 4
julia> (A)ᵀ
2×2 transpose(::Matrix{Int64}) with eltype Int64:
1 3
2 4
Here's another option if you don't like unicode:
julia> struct T end; Base.:(^)(A, ::Type{T}) = transpose(A)
julia> A^T
2×2 transpose(::Matrix{Int64}) with eltype Int64:
1 3
2 4
Okay, I see. what's the \xxx command for getting the T superscript?
Mason Protter (May 12 2021 at 21:53):It's \^T<TAB>. BTW, you can always find these by pasting them into the help> mode repl:
help?> ᵀ
"ᵀ" can be typed by \^T<tab>
search: ᵀ
No documentation found.
Summary
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struct ᵀ <: Any
Great. That's really helpful. Thanks
Mason Protter (May 12 2021 at 21:55):If you're on version 1.6 or later, another option is to locally shadow the ' variable in a let block or whatever.
julia> let var"'" = transpose
A'
end
2×2 transpose(::Matrix{Int64}) with eltype Int64:
1 3
2 4
This can be handy when you have like a function body or something that has a few transposes in it and you want to be explicit about what means what
Mason Protter (May 12 2021 at 21:55):Happy to help!
Last updated: Oct 02 2023 at 04:34 UTC