Yes, it is my post in Stackoverflow :) Thanks,
Charles On 25 September 2015 at 10:46, Tim Holy <tim.h...@gmail.com> wrote: > See also http://stackoverflow.com/a/32778103/1939814 > > --Tim > > On Friday, September 25, 2015 09:55:31 AM Charles Novaes de Santana wrote: > > Hi Valentin, > > > > Thanks a lot for your suggestion! It makes exactly what I need, with a > > clear code. I still don't know if efficiency will be an issue for my > > problems, but I hope it won't. > > > > Just don't agree with your advice to only post in one place. Is there any > > special reason for it besides the overlap of users? > > > > I see some differences between asking in the mailing-list or in > > stackoverflow, even if there is an overlap between of users of both > forums. > > In stackoverflow there is kind of a competition of the best responses > that > > I think is interesting, we can learn a lot from everyone there. And I > think > > it is not the focus of this list. Just my opinion. > > > > By the way, the final solution for my problem is the following piece of > > code: > > > > using Images > > > > function findMat(mat,value) > > return(collect(zip(ind2sub(size(mat),find( x -> x == value, > mat))...))); > > end > > > > mat = [1 1 0 0 0 ; 1 1 0 0 0 ; 0 0 0 0 1 ; 0 0 0 1 1] > > > > labels = label_components(mat); > > > > for c in 1:maximum(labels) > > comp = findMat(labels,c); > > println("Component $c is composed by the following elements > > (row,col)"); > > println("$comp\n"); > > end > > > > > > Thanks again for your help! > > > > Best, > > > > Charles > > > > On 25 September 2015 at 09:07, Valentin Churavy <v.chur...@gmail.com> > wrote: > > > Hej Charles, > > > > > > in the future please only post in one place. A lot of the people who > > > answer on SO are also here. > > > > > > You can use the label_components function in Images.jl > > > > https://github.com/timholy/Images.jl/blob/master/doc/function_reference.md > > > #label_components To get the the list of coordinates for each > components > > > you then would have to do something along the line of. > > > > > > for c in 1:maximum(labels) > > > > > > find(x-> x == c, labels) > > > > > > end > > > > > > Not very efficient but that should get you started. > > > > > > On Friday, 25 September 2015 07:56:20 UTC+9, Charles Santana wrote: > > >> Assume I have the following matrix: > > >> mat = [1 1 0 0 0 ; 1 1 0 0 0 ; 0 0 0 0 1 ; 0 0 0 1 1] > > >> > > >> Considering as a "component" a group of neighbour elements that have > > >> value '1', how to identify that this matrix has 2 components and which > > >> vertices compose each one? > > >> > > >> For the matrix *mat* above I would like to find the following result: > > >> > > >> Component 1 is composed by the following elements of the matrix > > >> > > >> (row,column): > > >> (1,1) > > >> (1,2) > > >> (2,1) > > >> (2,2) > > >> > > >> Component 2 is composed by the following elements: > > >> (3,5) > > >> (4,4) > > >> (4,5) > > >> > > >> I can use Graph algorithms like this > > >> < > http://graphsjl-docs.readthedocs.org/en/latest/algorithms.html#connected > > >> -components> to identify components in square matrices. However such > > >> algorithms can not be used for non-square matrices like the one I > > >> present here. > > >> > > >> Any idea will be much appreciated. > > >> > > >> I am open if your suggestion involves the use of a Python library + > > >> PyCall for example. Although I would prefer to use a pure Julia > solution. > > >> > > >> Regards > > >> Charles > > >> P.S.: Just asked the same question in Stackoverflow: > > >> > https://stackoverflow.com/questions/32772190/how-to-find-connected-compon > > >> ents-in-a-matrix-using-julia > > >> > > >> -- > > >> 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
