MATLAB Central Newsreader - vectorization problem part II

vectorization problem part II

Nick Valensi — Sat, 21 Nov 2009 15:03:03 -0500

I've another problem that seems so simple but i can't figure it out. Well i can, but not in a fast way. I still have this matrix for example:

5 1
5 3
5 2
6 2.5
6 2.1
6 2.9
7 8
7 9
7 1

this matrix is ordered based on the first row. For all similar values in this first row i also want to order the values in de second row. So then you get this:

5 1
5 2
5 3
6 2.1
6 2.5
6 2.9
7 1
7 8
7 9

Looks so simple, i tried that with a combination of accumarray and sortrows..that didn't work though. Any smart people here that can help me? No more questions after this one..well maybe 1 :)

-NV-

Re: vectorization problem part II

Bruno Luong — Sat, 21 Nov 2009 15:55:07 -0500

>> a=[5 1
5 3
5 2
6 2.5
6 2.1
6 2.9
7 8
7 9
7 1];

>> sortrows(a)

ans =

    5.0000 1.0000
    5.0000 2.0000
    5.0000 3.0000
    6.0000 2.1000
    6.0000 2.5000
    6.0000 2.9000
    7.0000 1.0000
    7.0000 8.0000
    7.0000 9.0000

Seems working fine to me

Bruno

Re: vectorization problem part II

Nick Valensi — Sat, 21 Nov 2009 16:11:05 -0500

Ok, in fact that did work. I just made my example a bit too simple. But after rearranging some collumns i figured it out.

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <he92gq$bqh$1@fred.mathworks.com>...
> >> a=[5 1
> 5 3
> 5 2
> 6 2.5
> 6 2.1
> 6 2.9
> 7 8
> 7 9
> 7 1];
>
> >> sortrows(a)
>
> ans =
>
> 5.0000 1.0000
> 5.0000 2.0000
> 5.0000 3.0000
> 6.0000 2.1000
> 6.0000 2.5000
> 6.0000 2.9000
> 7.0000 1.0000
> 7.0000 8.0000
> 7.0000 9.0000
>
> Seems working fine to me
>
> Bruno

Re: vectorization problem part II

Nick Valensi — Sat, 21 Nov 2009 18:11:06 -0500

The problem was more that the collumns i want to sort are not the first two collumns, but like the 4th en 11 th collumn. I know rearranged the collumns but i bet it's possible in another way as well.

"Nick Valensi" <G.vaneck@student.tudelft.nl> wrote in message <he93ep$91d$1@fred.mathworks.com>...
> Ok, in fact that did work. I just made my example a bit too simple. But after rearranging some collumns i figured it out.
>
> "Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <he92gq$bqh$1@fred.mathworks.com>...
> > >> a=[5 1
> > 5 3
> > 5 2
> > 6 2.5
> > 6 2.1
> > 6 2.9
> > 7 8
> > 7 9
> > 7 1];
> >
> > >> sortrows(a)
> >
> > ans =
> >
> > 5.0000 1.0000
> > 5.0000 2.0000
> > 5.0000 3.0000
> > 6.0000 2.1000
> > 6.0000 2.5000
> > 6.0000 2.9000
> > 7.0000 1.0000
> > 7.0000 8.0000
> > 7.0000 9.0000
> >
> > Seems working fine to me
> >
> > Bruno

Re: vectorization problem part II

Bruno Luong — Sat, 21 Nov 2009 19:23:03 -0500

"Nick Valensi" <G.vaneck@student.tudelft.nl> wrote in message <he9afq$fmp$1@fred.mathworks.com>...
> The problem was more that the collumns i want to sort are not the first two collumns, but like the 4th en 11 th collumn. I know rearranged the collumns but i bet it's possible in another way as well.

Well, you should read more carefully the help of sortrows, especially the second input.

Bruno