Thank you very much, Douglas, for your great suggestions!
Best,
Charles
On Thu, Sep 11, 2014 at 7:38 PM, Douglas Bates <dmba...@gmail.com> wrote:
> The short answer is vcat, as in
>
> julia> A = Array(Int,(0,2))
> 0x2 Array{Int64,2}
>
> julia> vcat(A,[1,2]')
> 1x2 Array{Int64,2}:
> 1 2
>
> Note that the ' is important as it cause the column vector [1,2] to be
> reshaped into a 1 by 2 matrix.
>
> You may find it more effective to create the columns separately using
> push! and then use hcat to create the matrix when you are done, if this is
> feasible. Using push! to append a new element onto the end of a vector is
> likely to be more efficient than vcat'ing matrices.
>
> julia> c1 = Int[]; c2 = Int[]
> 0-element Array{Int64,1}
>
> julia> for i in 1:10
> push!(c1,i)
> push!(c2,abs2(i))
> end
>
> julia> hcat(c1,c2)
> 10x2 Array{Int64,2}:
> 1 1
> 2 4
> 3 9
> 4 16
> 5 25
> 6 36
> 7 49
> 8 64
> 9 81
> 10 100
>
>
>
> On Thursday, September 11, 2014 11:54:45 AM UTC-5, Charles Santana wrote:
>>
>>
>> Dear all,
>>
>> I would like to create dynamically a matrix with two columns and N rows
>> (where N can be any number between 0 and 1000). I thought I could do it by
>> using the function "cat", but I am facing some problems with this.
>>
>> My code:
>> A=[];
>> (...)
>> A=cat(1,A,[1 2]);
>>
>> Is it a good way to create a matrix without defining its dimension a
>> priori?
>>
>> I was expecting that A would be a matrix 1x2, but I got the following
>> error message:
>>
>> ERROR: mismatch in dimension 2
>> in cat_t at abstractarray.jl:689
>> in cat at abstractarray.jl:666
>>
>> I am using julia Version 0.4.0-dev+523 (2014-09-10 15:51 UTC)
>>
>> Thank you in advance for any comment,
>>
>> Charles
>>
>> --
>> Um axé! :)
>>
>> --
>> Charles Novaes de Santana, PhD
>> http://www.imedea.uib-csic.es/~charles
>>
>
--
Um axé! :)
--
Charles Novaes de Santana, PhD
http://www.imedea.uib-csic.es/~charles
