How about this?
julia> sinc{T<:AbstractFloat}(x::T) = x != 0 ? sin(π*x)/(π*x) : one(T)
sinc (generic function with 1 method)
julia> methods(sinc)
# 1 method for generic function "sinc":
sinc{T<:AbstractFloat}(x::T<:AbstractFloat) at none:1
julia> @vectorize_1arg AbstractFloat sinc
sinc (generic function with 4 methods)
julia> methods(sinc)
# 4 methods for generic function "sinc":
sinc{T<:AbstractFloat}(x::T<:AbstractFloat) at none:1
sinc{T<:AbstractFloat}(::AbstractArray{T<:AbstractFloat,1}) at operators.jl:380
sinc{T<:AbstractFloat}(::AbstractArray{T<:AbstractFloat,2}) at operators.jl:381
sinc{T<:AbstractFloat}(::AbstractArray{T<:AbstractFloat,N}) at operators.jl:383
julia> @time sinc(rand(10_000));
0.055184 seconds (45.92 k allocations: 2.139 MB)
julia> @time sinc(rand(10_000));
0.000251 seconds (10 allocations: 156.563 KB)
julia> @code_warntype sinc(rand(10_000))
Variables:
#102#x::Array{Float64,1}
#s76::Int64
#s75::Int64
#s74::Int64
#101#i::Int64
#s73::Int64
Body:
begin # operators.jl, line 380:
GenSym(8) = (Base.arraylen)(#102#x::Array{Float64,1})::Int64
GenSym(0) = $(Expr(:new, UnitRange{Int64}, 1, :(((top(getfield))(Base.Intr
insics,:select_value)::I)((Base.sle_int)(1,GenSym(8))::Bool,GenSym(8),(Base.box)
(Int64,(Base.sub_int)(1,1)))::Int64)))
GenSym(1) = (Base.box)(Int64,(Base.checked_sadd)((Base.box)(Int64,(Base.ch
ecked_ssub)((top(getfield))(GenSym(0),:stop)::Int64,(top(getfield))(GenSym(0),:s
tart)::Int64)),1))
0:
GenSym(3) = (top(ccall))(:jl_alloc_array_1d,(top(apply_type))(Base.Array,F
loat64,1)::Type{Array{Float64,1}},(top(svec))(Base.Any,Base.Int)::SimpleVector,A
rray{Float64,1},0,GenSym(1),0)::Array{Float64,1}
#s76 = 1
#s75 = (top(getfield))(GenSym(0),:start)::Int64
#s74 = 0
unless (Base.box)(Base.Bool,(Base.not_int)(#s74::Int64 === GenSym(1)::Bool
)) goto 2
3:
#s74 = (Base.box)(Base.Int,(Base.add_int)(#s74::Int64,1))
GenSym(10) = #s75::Int64
GenSym(11) = (Base.box)(Base.Int,(Base.add_int)(#s75::Int64,1))
#s73 = 1
GenSym(12) = GenSym(10)
GenSym(13) = (Base.box)(Base.Int,(Base.add_int)(1,1))
#101#i = GenSym(12)
#s73 = GenSym(13)
GenSym(14) = GenSym(11)
GenSym(15) = (Base.box)(Base.Int,(Base.add_int)(2,1))
#s75 = GenSym(14)
#s73 = GenSym(15)
GenSym(4) = (Main.sinc)((Base.arrayref)(#102#x::Array{Float64,1},#101#i::I
nt64)::Float64)::Float64
$(Expr(:type_goto, 0, GenSym(4)))
$(Expr(:boundscheck, false))
(Base.arrayset)(GenSym(3),GenSym(4),#s76::Int64)::Array{Float64,1}
$(Expr(:boundscheck, :(Main.pop)))
#s76 = (Base.box)(Base.Int,(Base.add_int)(#s76::Int64,1))
4:
unless (Base.box)(Base.Bool,(Base.not_int)((Base.box)(Base.Bool,(Base.not_
int)(#s74::Int64 === GenSym(1)::Bool goto 3
2:
1:
return GenSym(3)
end::Array{Float64,1}
julia> sinc(rand(4, 4))
4x4 Array{Float64,2}:
0.671308 0.28010.110566 0.0508818
0.201512 0.416824 0.993366 0.537811
0.999858 0.74607 0.836841 0.0222563
0.592876 0.667453 0.612684 0.81811
julia> sinc(rand(4, 4, 2))
4x4x2 Array{Float64,3}:
[:, :, 1] =
0.1301 0.406598 0.95419 0.0530077
0.810275 0.917711 0.94 0.289211
0.0391342 0.970136 0.456169 0.34722
0.565740.726088 0.956873 0.99049
[:, :, 2] =
0.632377 0.844147 0.963265 0.0472808
0.569625 0.834078 0.183842 0.323166
0.51727 0.989112 0.568156 0.874306
0.533161 0.988943 0.931382 0.133851
julia>
Ismael Venegas Castelló
*Data Analyst*
Cel. 044 55 6434 0229
ivene...@richit.com.mx
Cerro San Francisco 357, C.P. 04200
Campestre Churubusco, Coyoacán
Ciudad de México
Tel. 6718 1818
richit.com.mx
2015-12-27 15:00 GMT-06:00 alan souza :
> Thanks for the tip. I was trying to annotate the function call before the
> loop without success.
>
> Do you know the reason for the speedup? Because the extra allocations
> still happening albeit a little less.
>
> thanks
>
> On Sunday, December 27, 2015 at 5:07:56 PM UTC-2, Lutfullah Tomak wrote:
>>
>> It seems adding typecheck is 2x improvements in my laptop.
>>y = zeros(T, n)
>> for i in eachindex(X)
>> y[i] = F(X[i])::T
>> end
>> return y
>>
>
