Add Type(dims) constructors for SparseMatrixCSC and SparseVector

Support the following:
SparseMatrixCSC(::Dims{2})
SparseMatrixCSC(::Integer, ::Integer)
SparseMatrixCSC{Tv}(::Dims{2})
SparseMatrixCSC{Tv}(::Integer, ::Integer)
SparseMatrixCSC{Tv,Ti}(::Dims{2})
SparseMatrixCSC{Tv,Ti}(::Integer, ::Integer)
SparseVector(::Dims{1})
SparseVector(::Integer)
SparseVector{Tv}(::Dims{1})
SparseVector{Tv}(::Integer)
SparseVector{Tv,Ti}(::Dims{1})
SparseVector{Tv,Ti}(::Integer)

Author: martinholters

base/sparse/sparse.jl

@@ -2,7 +2,7 @@
 
 module SparseArrays
 
-using Base: ReshapedArray, promote_op, setindex_shape_check, to_shape
+using Base: ReshapedArray, promote_op, setindex_shape_check, to_shape, check_array_size
 using Base.Sort: Forward
 using Base.LinAlg: AbstractTriangular, PosDefException
 

base/sparse/sparsematrix.jl

@@ -13,16 +13,22 @@ immutable SparseMatrixCSC{Tv,Ti<:Integer} <: AbstractSparseMatrix{Tv,Ti}
     nzval::Vector{Tv}       # Nonzero values
 
     function SparseMatrixCSC(m::Integer, n::Integer, colptr::Vector{Ti}, rowval::Vector{Ti}, nzval::Vector{Tv})
-        m < 0 && throw(ArgumentError("number of rows (m) must be ≥ 0, got $m"))
-        n < 0 && throw(ArgumentError("number of columns (n) must be ≥ 0, got $n"))
+        check_array_size(m, n)
         new(Int(m), Int(n), colptr, rowval, nzval)
     end
+    function SparseMatrixCSC(m::Integer, n::Integer)
+        check_array_size(m, n)
+        SparseMatrixCSC{Tv,Ti}(m, n, ones(Ti, n+1), Array{Ti}(0), Array{Tv}(0))
+    end
 end
 function SparseMatrixCSC(m::Integer, n::Integer, colptr::Vector, rowval::Vector, nzval::Vector)
     Tv = eltype(nzval)
     Ti = promote_type(eltype(colptr), eltype(rowval))
     SparseMatrixCSC{Tv,Ti}(m, n, colptr, rowval, nzval)
 end
+SparseMatrixCSC(m::Integer, n::Integer) = SparseMatrixCSC{Float64}(m, n)
+(::Type{SparseMatrixCSC{Tv}}){Tv}(m::Integer, n::Integer) = SparseMatrixCSC{Tv,Int}(m, n)
+(::Type{T}){T<:SparseMatrixCSC}(dims::Dims{2}) = T(dims[1], dims[2])
 
 size(S::SparseMatrixCSC) = (S.m, S.n)
 

base/sparse/sparsevector.jl

@@ -13,8 +13,8 @@ immutable SparseVector{Tv,Ti<:Integer} <: AbstractSparseVector{Tv,Ti}
     nzind::Vector{Ti}   # the indices of nonzeros
     nzval::Vector{Tv}   # the values of nonzeros
 
-    function SparseVector(n::Integer, nzind::Vector{Ti}, nzval::Vector{Tv})
-        n >= 0 || throw(ArgumentError("The number of elements must be non-negative."))
+    function SparseVector(n::Integer, nzind::Vector{Ti}=Ti[], nzval::Vector{Tv}=Tv[])
+        check_array_size(n)
         length(nzind) == length(nzval) ||
             throw(ArgumentError("index and value vectors must be the same length"))
         new(convert(Int, n), nzind, nzval)
@@ -23,6 +23,9 @@ end
 
 SparseVector{Tv,Ti}(n::Integer, nzind::Vector{Ti}, nzval::Vector{Tv}) =
     SparseVector{Tv,Ti}(n, nzind, nzval)
+SparseVector(n::Integer) = SparseVector{Float64}(n)
+(::Type{SparseVector{Tv}}){Tv}(n::Integer) = SparseVector{Tv,Int}(n)
+(::Type{T}){T<:SparseVector}(dims::Dims{1}) = T(dims[1])
 
 ### Basic properties
 

test/sparse/sparse.jl

@@ -5,6 +5,26 @@
 @test Base.SparseArrays.indtype(sparse(ones(Int8,2),ones(Int8,2),rand(2))) == Int8
 
 # check sparse matrix construction
+let sz = (3, 4)
+    X = SparseMatrixCSC(sz)
+    @test isa(X, SparseMatrixCSC{Float64,Int})
+    @test size(X) == sz
+    X = SparseMatrixCSC(sz...)
+    @test isa(X, SparseMatrixCSC{Float64,Int})
+    @test size(X) == sz
+    X = SparseMatrixCSC{Int16}(sz)
+    @test isa(X, SparseMatrixCSC{Int16,Int})
+    @test size(X) == sz
+    X = SparseMatrixCSC{Int16}(sz...)
+    @test isa(X, SparseMatrixCSC{Int16,Int})
+    @test size(X) == sz
+    X = SparseMatrixCSC{Int16,Int8}(sz)
+    @test isa(X, SparseMatrixCSC{Int16,Int8})
+    @test size(X) == sz
+    X = SparseMatrixCSC{Int16,Int8}(sz...)
+    @test isa(X, SparseMatrixCSC{Int16,Int8})
+    @test size(X) == sz
+end
 @test isequal(Array(sparse(complex(ones(5,5),ones(5,5)))), complex(ones(5,5),ones(5,5)))
 @test_throws ArgumentError sparse([1,2,3], [1,2], [1,2,3], 3, 3)
 @test_throws ArgumentError sparse([1,2,3], [1,2,3], [1,2], 3, 3)

test/sparse/sparsevector.jl

@@ -1,5 +1,27 @@
 # This file is a part of Julia. License is MIT: http://julialang.org/license
 
+### Non-initializing contrsutor
+let sz = (5,)
+    X = SparseVector(sz)
+    @test isa(X, SparseVector{Float64,Int})
+    @test size(X) == sz
+    X = SparseVector(sz...)
+    @test isa(X, SparseVector{Float64,Int})
+    @test size(X) == sz
+    X = SparseVector{Int16}(sz)
+    @test isa(X, SparseVector{Int16,Int})
+    @test size(X) == sz
+    X = SparseVector{Int16}(sz...)
+    @test isa(X, SparseVector{Int16,Int})
+    @test size(X) == sz
+    X = SparseVector{Int16,Int8}(sz)
+    @test isa(X, SparseVector{Int16,Int8})
+    @test size(X) == sz
+    X = SparseVector{Int16,Int8}(sz...)
+    @test isa(X, SparseVector{Int16,Int8})
+    @test size(X) == sz
+end
+
 ### Data
 
 spv_x1 = SparseVector(8, [2, 5, 6], [1.25, -0.75, 3.5])