Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Creating Adjacency Matrix from a dataset
Replies: 10   Last Post: Oct 7, 2016 1:01 AM

 Messages: [ Previous | Next ]
 Bruno Luong Posts: 9,822 Registered: 7/26/08
Re: Creating Adjacency Matrix from a dataset
Posted: Apr 10, 2013 5:28 AM

"Tehmina" wrote in message <kk33jl\$nl2\$1@newscl01ah.mathworks.com>...
> "Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <kk0n50\$639\$1@newscl01ah.mathworks.com>...
> > A=[0 1
> > 0 2
> > 0 5
> > 1 2
> > 1 3
> > 1 4
> > 2 3
> > 2 5
> > 3 1
> > 3 4
> > 3 5
> > 4 0
> > 4 2
> > 5 2
> > 5 4];
> >

> > >> accumarray(A+1,1)
> >
> > ans =
> >
> > 0 1 1 0 0 1
> > 0 0 1 1 1 0
> > 0 0 0 1 0 1
> > 0 1 0 0 1 1
> > 1 0 1 0 0 0
> > 0 0 1 0 1 0
> >
> > % Bruno

>
> hi Bruno Luong
> thanks for the solution and your time. this solution works well with small example. the actuall size of dataset i am working on is big. it has 1049866 rows in array A. and when i applied your solution to that dataset it gives me following error massege:
>
> ??? Error using ==> accumarray
> Maximum variable size allowed by the program is exceeded.
>
> now what shud i do? plz help
> Thanks
>

Create in sparse format:

accumarray(A+1,1,[],[],0,true)

or equivalently use sparse() command

sparse(A(:,1)+1,A(:,2)+1,1)

% Bruno

Date Subject Author
4/9/13 Guest
4/9/13 kinor
4/9/13 Bruno Luong
4/10/13 Guest
4/10/13 Bruno Luong
4/16/13 Tehmina
2/10/16 vignesh raju
2/11/16 Bruno Luong
10/29/13 Pramit Mazumdar
10/29/13 John D'Errico
10/7/16 Maziar Isapour