Add repeat vector #2409
Add repeat vector #2409
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| expanded = reshape(x, (size(x)..., 1)) | ||
| repeated = repeat(expanded, outer = (1, rv.n, 1)) | ||
| return repeated |
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this could just be
return repeat(x, size(x)..., rv.n)There was a problem hiding this comment.
That would do this:
julia> RepeatVector(2)(rand(3)) |> size
(9, 2)
julia> RepeatVector(2)(rand(3,5)) |> size
(9, 25, 2)
julia> RepeatVector(2)(rand(3,5,7)) |> size
(9, 25, 49, 2)Perhaps you meant:
julia> function (rv::RepeatVector)(x::AbstractArray{T}) where {T}
repeated = repeat(x, ntuple(_->1, ndims(x))..., rv.n)
end
julia> RepeatVector(2)(rand(3)) |> size
(3, 2)
julia> RepeatVector(2)(rand(3,5)) |> size
(3, 5, 2)
julia> RepeatVector(2)(rand(3,5,7)) |> size
(3, 5, 7, 2)| """ | ||
| RepeatVector(n::Int) | ||
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| Repeat the input `n` times along the last dimension. |
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this should specify that an extra dimension is added first.
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| """ | ||
| RepeatVector(n::Int) |
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RepeatArray is maybe a better name.
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| # Examples | ||
| ```jldoctest | ||
| julia> rv = RepeatVector(3) |
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in a jldoctest block each line should also have the corresponding output, otherwise the doctests will fail
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I would be ok with adding a layer like this, although I don't like the naming and I can't think of a really good one. |
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What is this used for? And what is the intended behaviour, on arrays of various dimensions? I'm not sure the code matches the words, nor the example given. julia> RepeatVector(2)(rand(3)) |> size
(3, 2, 1)
julia> RepeatVector(2)(rand(3,5)) |> size
(3, 10, 1)
julia> RepeatVector(2)(rand(3,5,7)) |> size
(3, 10, 7, 1)
julia> rv = RepeatVector(3);
julia> rv([1, 2, 3]) # example says 3×3 Matrix
3×3×1 Array{Int64, 3}: |
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The lack of clarity on how this layer should behave suggest to me that we might not want it as a built-in. Now, the good news is that Flux doesn't require a custom layer type for everything. In this case, it suffices to use a plain function/closure: function repeatvector(x::AbstractArray, n::Int)
expanded = reshape(x, (size(x)..., 1))
repeated = repeat(expanded, outer = (1, rv.n, 1))
return repeated
end
repeatvector(n::Int) = x -> repeatvector(x, n)
f = repeatvector(2)
# or, using built-in types:
f = Base.Fix2(repeatvector, n) |
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Going along Brian's point, even if we were to include this, I think it ought to be a function not a struct. Though I tend to lean towards not including it. |
RepeatVector Layer like in keras.
PS: I'm still new to contributing here, so if "trivial layers" like these are not requested, and rather something each user can implement on their own, then please let me know
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