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Topic: second largest element in a matrix
Replies: 32   Last Post: May 5, 2013 10:31 AM

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 Jos Posts: 1,268 Registered: 10/24/08
Re: second largest element in a matrix
Posted: Apr 6, 2009 4:49 PM
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"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <grdhld\$577\$1@fred.mathworks.com>...
> Walter Roberson <roberson@hushmail.com> wrote in message <STjCk.14881\$Il.4473@newsfe09.iad>...
> > Oluwa KuIse wrote:
> >

> > > Can anyone pls tell me how I can find the second (or third) largest element in a
> > > matrix AND its position.

> >
> > The algorithms that people gave all ran in -at least- time N (length of the
> > matrix) times the number of largest elements to be found.
> >
> > I was interested to discover a couple of weeks ago that there are simple
> > algorithms that for any fixed number L of largest elements, are able to
> > execute a -single- pass over the array and using L (or was it L+1 ?)
> > temporary storage locations, find the L largest values.
> >
> > Unfortunately in the short time I put into reading the algorithm, I did
> > not understand how the algorithm worked, so I cannot describe it here.
> > And I no longer recall where I found the algorithm -- though either as
> > a reference here or on wikipedia are the two most likely candidates.

>
> While searching something related to a stable quicksort I bump into this article:
> http://en.wikipedia.org/wiki/Selection_algorithm
>
> The interesting part are "Optimised Sorting algorithm" and "Tournament algorithm".
>
> Bruno

Bruno & Walter,

have you seen my KTHVALUE submission on the FEX?
http://www.mathworks.com/matlabcentral/fileexchange/23195

Best,
Jos

Date Subject Author
9/18/08 Oluwa KuIse
9/19/08 stephanie
9/19/08 Steven Lord
9/19/08 Oluwa KuIse
9/19/08 Pekka
9/19/08 Oluwa KuIse
9/21/08 Greg Heath
9/24/08 Walter Roberson
3/4/09 Justin
4/6/09 Bruno Luong
4/6/09 Jos
4/6/09 Bruno Luong
4/6/09 Bruno Luong
4/6/09 mike zander
4/7/09 Bruno Luong
4/7/09 Bruno Luong
4/3/09 Paul
11/7/12 sssbi2009@gmail.com
11/19/12 dpb
4/3/09 Paul
4/3/09 mike zander
4/3/09 mike zander
4/3/09 mike zander
4/3/09 Walter Roberson
4/3/09 mike zander
5/4/13 tilindg1@gmail.com
5/4/13 Nasser Abbasi
5/4/13 dpb
5/5/13 Nasser Abbasi
5/5/13 dpb
5/5/13 Bruno Luong
5/5/13 Nasser Abbasi
5/5/13 Bruno Luong

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