Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

better reducedim type inference #6994

Merged
merged 1 commit into from
May 28, 2014
Merged

better reducedim type inference #6994

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 17 additions & 3 deletions base/reducedim.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -110,7 +110,7 @@ function gen_reduction_body(N, f::Function)
end
end

reduction_init{T}(A::AbstractArray, region, initial::T) = fill!(similar(A,T,reduced_dims(A,region)), initial)
reduction_init{T}(A::AbstractArray, region, initial::T, Tr=T) = fill!(similar(A,Tr,reduced_dims(A,region)), initial)


### Pre-generated cases
Expand Down Expand Up @@ -143,11 +143,25 @@ minimum{T}(A::AbstractArray{T}, region) =

eval(ngenerate(:N, :(typeof(R)), :(_sum!{T,N}(R::AbstractArray, A::AbstractArray{T,N})), N->gen_reduction_body(N, +)))
sum!{R}(r::AbstractArray{R}, A::AbstractArray; init::Bool=true) = _sum!(initarray!(r, zero(R), init), A)
sum{T}(A::AbstractArray{T}, region) = _sum!(reduction_init(A, region, zero(T)+zero(T)), A)

eval(ngenerate(:N, :(typeof(R)), :(_prod!{T,N}(R::AbstractArray, A::AbstractArray{T,N})), N->gen_reduction_body(N, *)))
prod!{R}(r::AbstractArray{R}, A::AbstractArray; init::Bool=true) = _prod!(initarray!(r, one(R), init), A)
prod{T}(A::AbstractArray{T}, region) = _prod!(reduction_init(A, region, one(T)*one(T)), A)

for (f,init,op) in ((:sum,:zero,:+), (:prod,:one,:*))
_f = symbol(string("_",f,"!")) # _sum!, _prod!
@eval function $f{T}(A::AbstractArray{T}, region)
if method_exists($init, (Type{T},))
z = $op($init(T), $init(T))
Tr = typeof(z) == typeof($init(T)) ? T : typeof(z)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Why so simply set Tr = typeof(z) ?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If T is Real, then typeof(z) will be Int, and then you will get errors if there are non-integer values in the array.

On the other hand, if T is Int8, then z will have type Int, and I think we want Tr to be Int too. Hence the conditional.

else
# TODO: handle more heterogeneous sums. e.g. sum(A, 1) where
# A is a Matrix{Any} with one column of numbers and one of vectors
z = $init($f(A))
Tr = typeof(z)
end
$_f(reduction_init(A, region, z, Tr), A)
end
end

prod(A::AbstractArray{Bool}, region) = error("use all() instead of prod() for boolean arrays")

Expand Down
6 changes: 6 additions & 0 deletions test/reducedim.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,3 +45,9 @@ A = [1.0 3.0 6.0;
@test findmax(A, (1,)) == ([5.0 3.0 6.0], [2 3 5])
@test findmax(A, (2,)) == (reshape([6.0,5.0], 2, 1), reshape([5,2], 2, 1))
@test findmax(A, (1,2)) == (fill(6.0,1,1),fill(5,1,1))

# issue #6672
@test sum(Real[1 2 3; 4 5.3 7.1], 2) == reshape([6, 16.4], 2, 1)
@test std(FloatingPoint[1,2,3], 1) == [1.0]
@test sum({1 2;3 4},1) == [4 6]
@test sum(Vector{Int}[[1,2],[4,3]], 1)[1] == [5,5]