As I tried to explain before, Aptrs corresponds to a Ptr{Ptr{T}} *no matter
how many dimensions you have*. But showing the C code you want to use makes
your problem vastly clearer: now I know you want a `Ptr{Ptr{Ptr{Ptr{T}}}}`
for 4 dimensions.
I think you want a recursive solution, something like
```
ptr1d(A::AbstractVector) = pointer(A)
function ptr1d(A::AbstractArray)
colons = fill(:, ndims(A) - 1)
ptr1 = ptr1d(view(A, colons..., 1)) # get 1 pointer so we know the type
Aptr = Array{typeof(ptr1)}(size(A)[end])
Aptr[1] = ptr1
for i = 2:size(A)[end]
Aptr[i] = ptr1d(view(A, colons..., i))
end
Aptr
end
```
Then just pass `ptr1d(A)` as the last argument of your ccall.
Best,
--Tim
On Fri, Nov 4, 2016 at 10:07 AM, Alexander Lyapin <
lyapinaalexan...@gmail.com> wrote:
> Tim, thank you for reply!
>
> Everything was fine when I tried simple 2D array. Then I moved to real
> problem and got some errors... please check:
>
> -----test.c-----
> #include <stdio.h>
> double test(double ****param) {
> return param[1][1][1][1];
> }
>
>
> ----Julia-----
> # ar is Array{Float64,4}
>
> sz = size(ar)[1:end]
> Aptrs = Array{Ptr{eltype(ar)}}(sz)
> for I in CartesianRange(sz)
> Aptrs[I] = pointer(ar, sub2ind(size(ar), 1, I.I...))
> end
> println(ccall(("test","test"),Float64,(Ptr{Ptr{Ptr{Ptr{Float64}}}},),
> Aptrs))
>
>
> something is wrong here...
>
>
> пятница, 4 ноября 2016 г., 17:19:17 UTC+3 пользователь Tim Holy написал:
>>
>> ccall(sym, Void, (Ptr{Ptr{T}},), Aptrs)
>>
>> When you pass an array via `ccall`, it takes the pointer of the data,
>> which is why this produces a Ptr{Ptr{T}} from an Array{Ptr{T}}.
>>
>> Best,
>> --Tim
>>
>> On Fri, Nov 4, 2016 at 9:14 AM, Alexander Lyapin <lyapinaa...@gmail.com>
>> wrote:
>>
>>> but in C i have **double, wich is pointer pointer to array.
>>> Also in link that I gave, there an example for 2D where it is
>>> Ptr{Ptr{Float64}}
>>>
>>> But anyway, could you give an example for ccall in your case???
>>>
>>> пятница, 4 ноября 2016 г., 17:05:57 UTC+3 пользователь Yichao Yu написал:
>>>>
>>>> On Fri, Nov 4, 2016 at 9:22 AM, Alexander Lyapin
>>>> <lyapinaa...@gmail.com> wrote:
>>>> > There is a topic:
>>>> > https://groups.google.com/d/msg/julia-users/EK9oNzzaoAk/kJqagPL0Ku0J
>>>> >
>>>> > However could some one give an example how to pass 3-d or 4-d array
>>>> to C
>>>> > function.
>>>> >
>>>> > I have Array{Float64, 4} and for ccall I use
>>>> Ptr{Ptr{Ptr{Ptr{Float64}}}} as
>>>> > Type of parameter. Is there some way to make it more common for
>>>> > Array{Float64, N}??? Thank you
>>>>
>>>> No matter what the dimension is,it's always a `Ptr{eltype(array)}` in
>>>> C (`Ptr{Float64}` in thiscase) and since it's just a normalpointer,
>>>> you always need topass the dimensions explicitlyto C in another
>>>> argumetns.
>>>>
>>>
>>
