> Thanks all! I can now see what I was attempting makes no sense with the > array comprehension and why I needed a nested solution.
If you end up using it like so: vcat([[zeros(Int, k) for n = 1:binomial(J, k)] for k = 1:K]...) then have a look at https://github.com/mbauman/RaggedArrays.jl > On 21 Sep 2015 10:20, "Michael Hatherly" <michaelhathe...@gmail.com> wrote: > >> The indices need to all be independent since otherwise you’d end up >> producing an array with some rows/columns being of different length, which >> isn’t supported by Julia’s Array{T, N}. That’s fine for a loop since for >> i = 1:3, j = 1:i isn’t trying to fill up an array directly though. >> >> — Mike >> >> >> On Monday, 21 September 2015 10:59:31 UTC+2, Alan Crawford wrote: >>> >>> Thanks Mike - precisely what i was after. >>> >>> While this is a perfectly acceptable solution I wondered >>> whether, following Mauro's suggestion, it was worth opening an issue in any >>> case because it seems like it be nice to be able to link indexes in array >>> comprehensions in a similar way to for-loops. Views? >>> >>> >>> On Monday, 21 September 2015 09:49:57 UTC+1, Michael Hatherly wrote: >>>> >>>> MyArray = [[zeros(Int, k) for n = 1:binomial(J, k)] for k = 1:K] >>>> >>>> seems to do what you want I think. Using 2 nested 1-d comprehensions >>>> instead of a single 2-d comprehension. >>>> >>>> — Mike >>>> >>>> On Monday, 21 September 2015 10:37:06 UTC+2, Alan Crawford wrote: >>>>> >>>>> >>>>> Thanks Tomas. If I do: >>>>> >>>>> Y = [Array(Int64,n) for n in map(k -> binomial(J,k), 1:K)] >>>>> >>>>> Then Y[1] gives the desired result (i.e. Y[1][k] is a length 1 vector). >>>>> However, the issue for Y[2] and above. For example, if I do Y[2][k] where >>>>> k∈[1,binomial(J,2)] >>>>> then i get a length 1 vector, whereas I would like length 2 vector. >>>>> Similarly for Y[3][k] I would like a length 3 vector. >>>>> >>>>> >>>>> On Monday, 21 September 2015 09:23:56 UTC+1, Tomas Lycken wrote: >>>>>> >>>>>> Ah. >>>>>> >>>>>> Maybe [Array(Int64,n) for n in map(k -> binomial(J,k), 1:K)] is what >>>>>> you’re looking for? >>>>>> >>>>>> // T >>>>>> >>>>>> On Monday, September 21, 2015 at 10:18:31 AM UTC+2, Alan Crawford >>>>>> wrote: >>>>>> >>>>>> The lower case k is intentional. I didn't want such a 'large' array as >>>>>>> the one created when I use K because large parts of that array would be >>>>>>> redundant. Ideally, I want this array to be as small as possible, >>>>>>> especially since J and K might be quite a bit larger than in the >>>>>>> example. >>>>>>> >>>>>>> On Monday, 21 September 2015 09:13:53 UTC+1, Tomas Lycken wrote: >>>>>>>> >>>>>>>> Are you sure that’s not just a typo between k and K (note the case >>>>>>>> difference)? >>>>>>>> >>>>>>>> This works for me: >>>>>>>> >>>>>>>> J=10 >>>>>>>> K=3 >>>>>>>> MyArray = [Array(Int64,k) for k in 1:K, n in 1:binomial(J,K)] >>>>>>>> >>>>>>>> // T >>>>>>>> >>>>>>>> On Monday, September 21, 2015 at 10:08:13 AM UTC+2, Alan Crawford >>>>>>>> wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>>> >>>>>>>>> I'd like to be able to define an array of vectors where the number >>>>>>>>> of vectors in the array is linked to the length of the vector. For >>>>>>>>> example, >>>>>>>>> I want to be define an array with say 10 scalars, 45 length 2 >>>>>>>>> vectors, 120 >>>>>>>>> length 3 vectors, .... and so on. Intuitively, I thought the >>>>>>>>> following code >>>>>>>>> might achieve this: >>>>>>>>> >>>>>>>>> J=10 >>>>>>>>> K=3 >>>>>>>>> MyArray = [Array(Int64,k) for k in 1:K, n in 1:binomial(J,k)] >>>>>>>>> >>>>>>>>> >>>>>>>>> However, it seems i cannot use k to define the number of element >>>>>>>>> indexed by n. >>>>>>>>> >>>>>>>>> I was wondering if anyone knew how to create the desired array? >>>>>>>>> >>>>>>>>> Thanks >>>>>>>>> Alan >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>
