I've seen a discussion on this somewhere... here it is:
https://github.com/JuliaLang/julia/issues/6984, and there's more discussion
at https://groups.google.com/forum/#!topic/julia-users/alavN8tRdyI
No built-in solution so far from what I can see, although following the
first post there, you could define a type alias for an array that has
elements that are all the same Real subtype:
typealias RealArray{R<:Real} Array{R}
function f(x::RealArray, y::RealArray, z::RealArray) ...
On Friday, 26 June 2015 17:46:22 UTC+1, Linus Härenstam-Nielsen wrote:
>
> Ok, that makes sense. In that case what would be the best way to write a
> funcion that accepts several Real arrays (of not necessarily the same
> type)? Currently I'm using
>
> function f{T1,T2,T3 <: Real}(x::Array{T1}, y::Array{T2}, z::Array{T3})
> ...
> end
>
> But that gets messy very quickly if there are many arguments.
>
> On Friday, June 26, 2015 at 6:00:25 PM UTC+2, Tim Wheeler wrote:
>>
>> Hello Linus,
>>
>> This is based on how array types are defined. In general, Vector{subtype}
>> is not a subtype of Vector{supertype}.
>> Try this:
>>
>> f{R<:Real}(x::Array{R}) = x
>>
>> -Tim
>>
>> On Friday, June 26, 2015 at 8:38:12 AM UTC-7, Linus Härenstam-Nielsen
>> wrote:
>>>
>>> I ran into a problem with types today that I don't know how to interpret.
>>>
>>> If I define a function according to
>>> f(x::Real) = x
>>> it returns x as expected as long as the type of x is a subtype of Real.
>>> However if I define
>>> f(x::Array{Real}) = x
>>> it throws MethodError no matter what I pass as argument. For example
>>> when I try to pass it an Int array:
>>> f([1 2 3; 3 4 5])
>>> ERROR: MethodError: `f` has no method matching f(::Array{Int64,2})
>>>
>>> I would expect it to work like
>>> f{T<:Real}(x::Array{T}) = x
>>> and accept any array of reals. Am I missing something?
>>>
>>>
>>>
>>>
