https://github.com/JuliaLang/julia
Tip revision: e8cb96bc6d6e74b0e9fdfd80171c0e284d19eea7 authored by Jiahao Chen on 09 August 2014, 03:21:53 UTC
Merge pull request #7928 from wlbksy/patch-1
Merge pull request #7928 from wlbksy/patch-1
Tip revision: e8cb96b
subarray.jl
## subarrays ##
typealias RangeIndex Union(Int, Range{Int}, Range1{Int})
type SubArray{T,N,A<:AbstractArray,I<:(RangeIndex...,)} <: AbstractArray{T,N}
parent::A
indexes::I
dims::Dims
strides::Array{Int,1} # for accessing parent with linear indexes
first_index::Int
# Note: no bounds-checking on construction. See issue #4044
#linear indexing constructor (scalar)
if N == 0 && length(I) == 1 && A <: Array
function SubArray(p::A, i::(Int,))
new(p, i, (), Int[], i[1])
end
#linear indexing constructor (ranges)
elseif N == 1 && length(I) == 1 && A <: Array
function SubArray(p::A, i::(Range1{Int},))
new(p, i, (length(i[1]),), [1], first(i[1]))
end
function SubArray(p::A, i::(Range{Int},))
new(p, i, (length(i[1]),), [step(i[1])], first(i[1]))
end
else
function SubArray(p::A, i::I)
newdims = Array(Int, 0)
newstrides = Array(Int, 0)
newfirst = 1
pstride = 1
for j = 1:length(i)
if isa(i[j], Int)
newfirst += (i[j]-1)*pstride
else
push!(newdims, length(i[j]))
#may want to return error if step(i[j]) <= 0
push!(newstrides, isa(i[j],Range1) ? pstride :
pstride * step(i[j]))
newfirst += (first(i[j])-1)*pstride
end
pstride *= size(p,j)
end
new(p, i, tuple(newdims...), newstrides, newfirst)
end
end
end
#linear indexing sub (may want to rename as slice)
function sub{T,N}(A::Array{T,N}, i::(RangeIndex,))
SubArray{T,(isa(i[1], Int) ? 0 : 1),typeof(A),typeof(i)}(A, i)
end
function sub{T,N}(A::AbstractArray{T,N}, i::NTuple{N,RangeIndex})
L = length(i)
while L > 0 && isa(i[L], Int); L-=1; end
i0 = map(j -> isa(j, Int) ? (j:j) : j, i[1:L])
i = ntuple(length(i), k->(k<=L ? i0[k] : i[k]))
SubArray{T,L,typeof(A),typeof(i)}(A, i)
end
sub{N}(A::SubArray, i::NTuple{N,RangeIndex}) = sub(A, i...)
sub(A::AbstractArray, i::RangeIndex...) = sub(A, i)
function sub(A::SubArray, i::RangeIndex...)
L = length(i)
while L > 0 && isa(i[L], Int); L-=1; end
j = 1
newindexes = Array(RangeIndex,length(A.indexes))
for k = 1:length(A.indexes)
if isa(A.indexes[k], Int)
newindexes[k] = A.indexes[k]
else
r = A.indexes[k]
ri = (isa(i[j],Int) && j<=L) ? (i[j]:i[j]) : i[j]
newindexes[k] = step(r) == 1 ? (first(r)-1) + ri : first(r) + (ri-1)*step(r)
j += 1
end
end
ni = tuple(newindexes...)
SubArray{eltype(A),L,typeof(A.parent),typeof(ni)}(A.parent, ni)
end
function slice{T,N}(A::AbstractArray{T,N}, i::NTuple{N,RangeIndex})
n = 0
for j = i; if !isa(j, Int); n += 1; end; end
SubArray{T,n,typeof(A),typeof(i)}(A, i)
end
# Throw error on slice dimension mismatch
slice{T,N,M}(A::AbstractArray{T,N}, i::NTuple{M,RangeIndex}) = throw(BoundsError())
slice(A::AbstractArray, i::RangeIndex...) = slice(A, i)
function slice(A::SubArray, i::RangeIndex...)
j = 1
newindexes = Array(RangeIndex,length(A.indexes))
for k = 1:length(A.indexes)
if isa(A.indexes[k], Int)
newindexes[k] = A.indexes[k]
else
r = A.indexes[k]
newindexes[k] = step(r) == 1 ? (first(r)-1) + i[j] : first(r) + (i[j]-1)*step(r)
j += 1
end
end
slice(A.parent, tuple(newindexes...))
end
# Generic fallback for Colon translation
sub(A::AbstractArray, I...) = sub(A, ntuple(length(I), i-> isa(I[i], Colon) ? (1:size(A,i)) : I[i])...)
slice(A::AbstractArray, I...) = slice(A, ntuple(length(I), i-> isa(I[i], Colon) ? (1:size(A,i)) : I[i])...)
### rename the old slice function ###
##squeeze all dimensions of length 1
#slice{T,N}(a::AbstractArray{T,N}) = sub(a, map(i-> i == 1 ? 1 : (1:i), size(a)))
#slice{T,N}(s::SubArray{T,N}) =
# sub(s.parent, map(i->!isa(i, Int) && length(i)==1 ?i[1] : i, s.indexes))
#
##slice dimensions listed, error if any have length > 1
##silently ignores dimensions that are greater than N
#function slice{T,N}(a::AbstractArray{T,N}, sdims::Integer...)
# newdims = ()
# for i = 1:N
# next = 1:size(a, i)
# for j in sdims
# if i == j
# if size(a, i) != 1
# error("slice: dimension ", i, " has length greater than 1")
# end
# next = 1
# break
# end
# end
# newdims = tuple(newdims..., next)
# end
# sub(a, newdims)
#end
#function slice{T,N}(s::SubArray{T,N}, sdims::Integer...)
# newdims = ()
# for i = 1:length(s.indexes)
# next = s.indexes[i]
# for j in sdims
# if i == j
# if length(next) != 1
# error("slice: dimension ", i," has length greater than 1")
# end
# next = isa(next, Int) ? next : first(next)
# break
# end
# end
# newdims = tuple(newdims..., next)
# end
# sub(s.parent, newdims)
#end
### end commented code ###
size(s::SubArray) = s.dims
ndims{T,N}(s::SubArray{T,N}) = N
parent(s::SubArray) = s.parent
parentindexes(s::SubArray) = s.indexes
parent(a::AbstractArray) = a
parentindexes(a::AbstractArray) = ntuple(ndims(a), i->1:size(a,i))
copy(s::SubArray) = copy!(similar(s.parent, size(s)), s)
similar(s::SubArray, T, dims::Dims) = similar(s.parent, T, dims)
getindex{T}(s::SubArray{T,0,AbstractArray{T,0}}) = s.parent[]
getindex{T}(s::SubArray{T,0}) = s.parent[s.first_index]
getindex{T}(s::SubArray{T,1}, i::Integer) =
s.parent[s.first_index + (i-1)*s.strides[1]]
getindex{T}(s::SubArray{T,1}, i::Integer, j::Integer) =
j==1 ? s.parent[s.first_index + (i-1)*s.strides[1]] : throw(BoundsError())
getindex{T}(s::SubArray{T,2}, i::Integer, j::Integer) =
s.parent[s.first_index + (i-1)*s.strides[1] + (j-1)*s.strides[2]]
getindex{T}(s::SubArray{T,3}, i::Integer, j::Integer, k::Integer) =
s.parent[s.first_index + (i-1)*s.strides[1] + (j-1)*s.strides[2] + (k-1)*s.strides[3]]
getindex{T}(s::SubArray{T,4}, i::Integer, j::Integer, k::Integer, l::Integer) =
s.parent[s.first_index + (i-1)*s.strides[1] + (j-1)*s.strides[2] + (k-1)*s.strides[3] + (l-1)*s.strides[4]]
getindex{T}(s::SubArray{T,5}, i::Integer, j::Integer, k::Integer, l::Integer, m::Integer) =
s.parent[s.first_index + (i-1)*s.strides[1] + (j-1)*s.strides[2] + (k-1)*s.strides[3] + (l-1)*s.strides[4] + (m-1)*s.strides[5]]
getindex(s::SubArray, i::Real) = getindex(s, to_index(i))
getindex(s::SubArray, i0::Real, i1::Real) =
getindex(s, to_index(i0), to_index(i1))
getindex(s::SubArray, i0::Real, i1::Real, i2::Real) =
getindex(s, to_index(i0), to_index(i1), to_index(i2))
getindex(s::SubArray, i0::Real, i1::Real, i2::Real, i3::Real) =
getindex(s, to_index(i0), to_index(i1), to_index(i2), to_index(i3))
getindex(s::SubArray, i0::Real, i1::Real, i2::Real, i3::Real, i4::Real) =
getindex(s, to_index(i0), to_index(i1), to_index(i2), to_index(i3), to_index(i4))
getindex(s::SubArray, i0::Real, i1::Real, i2::Real, i3::Real, i4::Real, i5::Real) =
getindex(s, to_index(i0), to_index(i1), to_index(i2), to_index(i3), to_index(i4), to_index(i5))
getindex(s::SubArray, i0::Real, i1::Real, i2::Real, i3::Real, i4::Real, i5::Real, is::Int...) =
getindex(s, to_index(i0), to_index(i1), to_index(i2), to_index(i3), to_index(i4), to_index(5), is...)
getindex(s::SubArray, i::Integer) = s[ind2sub(size(s), i)...]
function getindex{T}(s::SubArray{T,2}, ind::Integer)
@inbounds strd2 = s.dims[1]
ind -= 1
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2]]
end
function getindex{T}(s::SubArray{T,3}, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
ind -= 1
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3]]
end
function getindex{T}(s::SubArray{T,4}, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
@inbounds strd4 = strd3*s.dims[3]
ind -= 1
i4 = div(ind,strd4)
ind -= i4*strd4
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3] + i4*s.strides[4]]
end
function getindex{T}(s::SubArray{T,5}, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
@inbounds strd4 = strd3*s.dims[3]
@inbounds strd5 = strd4*s.dims[4]
ind -= 1
i5 = div(ind,strd5)
ind -= i5*strd5
i4 = div(ind,strd4)
ind -= i4*strd4
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3] + i4*s.strides[4] + i5*s.strides[5]]
end
function getindex(s::SubArray, is::Integer...)
index = s.first_index
for i = 1:length(is)
isi = is[i]
if isi != 1
index += (is[i]-1)*s.strides[i]
end
end
s.parent[index]
end
getindex{T}(s::SubArray{T,1}, I::Range1{Int}) =
getindex(s.parent, (s.first_index+(first(I)-1)*s.strides[1]):s.strides[1]:(s.first_index+(last(I)-1)*s.strides[1]))
getindex{T}(s::SubArray{T,1}, I::Range{Int}) =
getindex(s.parent, (s.first_index+(first(I)-1)*s.strides[1]):(s.strides[1]*step(I)):(s.first_index+(last(I)-1)*s.strides[1]))
function getindex{T,S<:Integer}(s::SubArray{T,1}, I::AbstractVector{S})
t = Array(Int, length(I))
for i = 1:length(I)
t[i] = s.first_index + (I[i]-1)*s.strides[1]
end
getindex(s.parent, t)
end
function getindex{T}(s::SubArray{T,1}, I::AbstractVector{Bool})
t = Array(T, 0)
for i = 1:length(I)
if I[i]
push!(t, s.parent[s.first_index + (i-1)*s.strides[1]])
end
end
t
end
function translate_indexes(s::SubArray, I::Union(Real,AbstractArray)...)
n = length(I)
newindexes = Any[s.indexes...]
pdims = parentdims(s)
havelinear = n < ndims(s)
for i = 1:n-havelinear
newindexes[pdims[i]] = s.indexes[pdims[i]][I[i]]
end
lastdim = pdims[n]
if havelinear
newindexes = newindexes[1:lastdim]
newindexes[pdims[n]] = translate_linear_indexes(s, n, I[end], pdims)
end
newindexes
end
# translate a linear index vector I for dim n to a linear index vector for
# the parent array
function translate_linear_indexes(s, n, I, pdims)
idx = Array(Int, length(I))
ssztail = size(s)[n:]
indexestail = s.indexes[pdims[n:]]
# The next gets the strides of dimensions listed in pdims[n:end], relative to the stride of pdims[n]
pstrd = [1]
j = n+1
strd = 1
for i = pdims[n]+1:ndims(s.parent)
strd *= size(s.parent, i-1)
if j <= length(pdims) && i == pdims[j]
push!(pstrd, strd)
j += 1
end
end
# Compute the offset from any omitted dimensions
taildimsoffset = 0
for i = pdims[n]+1:ndims(s.parent)
thisI = s.indexes[i]
if isa(thisI, Integer)
taildimsoffset += (thisI-1)*stride(s.parent, i)
end
end
nd = length(pstrd)
for j=1:length(I)
su = ind2sub(ssztail,I[j]) # convert to particular location within indexes
K = taildimsoffset + 1
for k = 1:nd
K += pstrd[k]*(indexestail[k][su[k]]-1) # convert to particular location in parent
end
idx[j] = K
end
idx
end
function parentdims(s::SubArray)
nd = ndims(s)
dimindex = Array(Int, nd)
sp = strides(s.parent)
j = 1
for i = 1:ndims(s.parent)
r = s.indexes[i]
if j <= nd && (isa(r,Range) ? sp[i]*step(r) : sp[i]) == s.strides[j]
dimindex[j] = i
j += 1
end
end
dimindex
end
function getindex(s::SubArray, I::Union(Real,AbstractVector)...)
newindexes = translate_indexes(s, I...)
rs = index_shape(I...)
result = getindex(s.parent, newindexes...)
if isequal(rs, size(result))
return result
else
return reshape(result, rs)
end
end
setindex!(s::SubArray, v, i::Integer) = setindex!(s, v, ind2sub(size(s), i)...)
function setindex!{T}(s::SubArray{T,2}, v, ind::Integer)
@inbounds strd2 = s.dims[1]
ind -= 1
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2]] = v
s
end
function setindex!{T}(s::SubArray{T,3}, v, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
ind -= 1
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3]] = v
s
end
function setindex!{T}(s::SubArray{T,4}, v, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
@inbounds strd4 = strd3*s.dims[3]
ind -= 1
i4 = div(ind,strd4)
ind -= i4*strd4
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3] + i4*s.strides[4]] = v
s
end
function setindex!{T}(s::SubArray{T,5}, v, ind::Integer)
@inbounds strd2 = s.dims[1]
@inbounds strd3 = strd2*s.dims[2]
@inbounds strd4 = strd3*s.dims[3]
@inbounds strd5 = strd4*s.dims[4]
ind -= 1
i5 = div(ind,strd5)
ind -= i5*strd5
i4 = div(ind,strd4)
ind -= i4*strd4
i3 = div(ind,strd3)
ind -= i3*strd3
i2 = div(ind,strd2)
i1 = ind-i2*strd2
s.parent[s.first_index + i1*s.strides[1] + i2*s.strides[2] + i3*s.strides[3] + i4*s.strides[4] + i5*s.strides[5]] = v
s
end
function setindex!(s::SubArray, v, is::Integer...)
index = s.first_index
for i = 1:length(is)
index += (is[i]-1)*s.strides[i]
end
s.parent[index] = v
return s
end
setindex!{T}(s::SubArray{T,0,AbstractArray{T,0}},v) = setindex!(s.parent, v)
setindex!{T}(s::SubArray{T,0}, v) = setindex!(s.parent, v, s.first_index)
setindex!{T}(s::SubArray{T,1}, v, i::Integer) =
setindex!(s.parent, v, s.first_index + (i-1)*s.strides[1])
setindex!{T}(s::SubArray{T,2}, v, i::Integer, j::Integer) =
setindex!(s.parent, v, s.first_index +(i-1)*s.strides[1]+(j-1)*s.strides[2])
setindex!{T}(s::SubArray{T,3}, v, i::Integer, j::Integer, k::Integer) =
setindex!(s.parent, v, s.first_index +(i-1)*s.strides[1]+(j-1)*s.strides[2]+(k-1)*s.strides[3])
setindex!{T}(s::SubArray{T,4}, v, i::Integer, j::Integer, k::Integer, l::Integer) =
setindex!(s.parent, v, s.first_index +(i-1)*s.strides[1]+(j-1)*s.strides[2]+(k-1)*s.strides[3]+(l-1)*s.strides[4])
setindex!{T}(s::SubArray{T,5}, v, i::Integer, j::Integer, k::Integer, l::Integer, m::Integer) =
setindex!(s.parent, v, s.first_index +(i-1)*s.strides[1]+(j-1)*s.strides[2]+(k-1)*s.strides[3]+(l-1)*s.strides[4]+(m-1)*s.strides[5])
setindex!{T}(s::SubArray{T,1}, v, I::Range1{Int}) =
setindex!(s.parent, v, (s.first_index+(first(I)-1)*s.strides[1]):s.strides[1]:(s.first_index+(last(I)-1)*s.strides[1]))
setindex!{T}(s::SubArray{T,1}, v, I::Range{Int}) =
setindex!(s.parent, v, (s.first_index+(first(I)-1)*s.strides[1]):(s.strides[1]*step(I)):(s.first_index+(last(I)-1)*s.strides[1]))
function setindex!{T,S<:Integer}(s::SubArray{T,1}, v, I::AbstractVector{S})
t = Array(Int, length(I))
for i = 1:length(I)
t[i] = s.first_index + (I[i]-1)*s.strides[1]
end
setindex!(s.parent, v, t)
end
# to avoid ambiguity warning
function setindex!(s::SubArray, v, I::Real)
newindexes = translate_indexes(s, (I,))
setindex!(s.parent, v, newindexes...)
end
function setindex!(s::SubArray, v, I::Union(Real,AbstractArray)...)
newindexes = translate_indexes(s, I...)
setindex!(s.parent, v, newindexes...)
end
stride(s::SubArray, i::Integer) = i <= length(s.strides) ? s.strides[i] : s.strides[end]*s.dims[end]
convert{T}(::Type{Ptr{T}}, x::SubArray{T}) =
pointer(x.parent) + (x.first_index-1)*sizeof(T)
pointer(s::SubArray, i::Int) = pointer(s, ind2sub(size(s), i))
function pointer(s::SubArray, is::(Int...))
index = s.first_index
for n = 1:length(is)
index += (is[n]-1)*s.strides[n]
end
return pointer(s.parent, index)
end