Thread Subject: Help with finding index

I have an array of say :

 a =

     2 3 4
     5 6 2
     4 2 1
     7 2 4

I want to find the index of an exact vector.
For instance, I want to find the row index of vector [4 2 1], answer is 3(row 3).
The vector [7 2 4] will return index 4.

The find function does not work , any suggestion.

ade77 wrote:
> I have an array of say :
...>
> I want to find the index of an exact vector.
> For instance, I want to find the row index of vector ...

doc intersect

--

dpb <none@non.net> wrote in message <he7677$3mi$1@news.eternal-september.org>...
> ade77 wrote:
> > I have an array of say :
> ...>
> > I want to find the index of an exact vector.
> > For instance, I want to find the row index of vector ...
>
> doc intersect
>
> --

Thank you. Works perfectly

Hi,

the "Intersect" function works well in this case, but if I have this matrix

a =

     4 2 1
     5 6 2
     4 2 1
     7 2 4

And, If I want to find "all' rows index of vector [4 2 1], answers are rows 1 and 3.
[i,ii,iii]=Intersect(a,[4 2 1],'rows') give just the last row index, (3) in this case.

Look at ismember with the rows option.

"LCPC Yannick" <yannick.fargier@hotmail.fr> wrote in message <hfogon$jrk$1@fred.mathworks.com>...
> Hi,
>
> the "Intersect" function works well in this case, but if I have this matrix
>
> a =
>
> 4 2 1
> 5 6 2
> 4 2 1
> 7 2 4
>
> And, If I want to find "all' rows index of vector [4 2 1], answers are rows 1 and 3.
> [i,ii,iii]=Intersect(a,[4 2 1],'rows') give just the last row index, (3) in this case.


STRMATCH will also work

>> strmatch([4 2 1], a)

ans =

     1
     3

thank you Matt & Matt, it works perfectly.