I’d like to add the following example too, of using *both* inner and outer,
to show off the flexibility of repeat:
julia> repeat(A, inner=[1,2], outer=[2,1])
4x4 Array{Int64,2}:
1 1 2 2
3 3 4 4
1 1 2 2
3 3 4 4
Until I had tried that in the REPL myself, I didn’t really trust that I
actually understood what keywords really meant. Now I think I do.
// T
On Tuesday, June 17, 2014 2:36:39 PM UTC+2, Bruno Rodrigues wrote:
For outer, I think that it would be clearer to say that it repeats (or
> clones?) the whole array along the specified dimensions. For inner, I think
> it's ok.
>
> Looking at the tests for repeat, I think we could use this as an example:
>
> As an illustrative example, let's consider array A:
> A = [1 2;3 4]
>
> 2x2 Array{Int64,2}:
> 1 2
> 3 4
>
> If you want to repeat array A along the second dimension:
>
> repeat(A,inner=[1,1],outer=[1,2])
> 2x4 Array{Int64,2}:
> 1 2 1 2
> 3 4 3 4
>
> You can also repeat the columns first:
>
> repeat(A,inner=[1,2],outer=[1,1])
> 2x4 Array{Int64,2}:
> 1 1 2 2
> 3 3 4 4
>
>
>
> You can also create a new array that repeats A along a third dimension:
>
> repeat(A,inner=[1,1],outer=[1,1,2])
> 2x2x2 Array{Int64,3}:
> [:, :, 1] =
> 1 2
> 3 4
>
> [:, :, 2] =
> 1 2
> 3 4
>
>
> Is there a limit on how a docstring can be? Could we add more examples?
>
> On Thursday, June 12, 2014 4:59:14 PM UTC+2, John Myles White wrote:
>>
>> Rewriting the documentation for repeat would be great. I’m the guilty
>> party for that piece of documentation and agree that it’s not very good.
>> Rewriting it from scratch is probably a good idea.
>>
>> I’m not sure I think `tile` is much better than `outer`. Maybe we should
>> use something like `perelement` and `perslice` as the keywords? If we
>> revise the keywords, we should also find terms to describe one additional
>> piece of functionality I’d like to add to repeat: the ability to repeat
>> specific elements a distinct number of times. That’s the main thing that
>> repeat is missing that you’d get from R’s rep function.
>>
>> If you’re looking for good examples for the documentation, there are a
>> bunch of tests for `repeat` you could use as inspiration:
>> https://github.com/JuliaLang/julia/blob/b320b66db8fb97cc3b96fe4089b7b15528ab346c/test/arrayops.jl#L302
>>
>> — John
>>
>> On Jun 12, 2014, at 6:17 AM, Patrick O'Leary <[email protected]>
>> wrote:
>>
>> On Thursday, June 12, 2014 7:57:03 AM UTC-5, Bruno Rodrigues wrote:
>>>
>>> repeat() is much more useful that Matlab's repmat(), but the docstring
>>> is unclear, at least for me. Unfortunately, I don't have, right now, any
>>> proposals to correct it. Could maybe an example be added to the docstring?
>>> Maybe it could be clearer this way.
>>>
>>
>> I think an example would help make this immediately obvious. I also
>> wonder if the keyword arguments could be better--I don't have a good
>> alternative for "inner", but "tile" seems like a good alternative to
>> "outer". That may at least be useful in a rework of the doc.
>>
>> Note that you don't have to supply both keyword arguments, only one, so
>> if you're not using the feature of "inner" you can simply omit it.
>>
>>
>>
