Date: Feb 5, 2013 3:40 PM
Author: Jos
Subject: Re: access matrix
"amira ali" wrote in message <kerejb$qqn$1@newscl01ah.mathworks.com>...

> "Jos (10584)" wrote in message <keqi7l$934$1@newscl01ah.mathworks.com>...

> > "amira ali" wrote in message <keohlb$51a$1@newscl01ah.mathworks.com>...

> > > need help urgently

> > >

> > > i have location of interest points in matrix A(2*13 ) where 2 is x,y of point and 13 is total number of points for example:

> > > x y

> > > 72.6781959551728 46.7543453323974

> > > 71.9155271184922 100.930596158669

> > >

> > > and i have another matrix called flow (120*160) this matrix contain velocity of every pixel (v in x direction) and (v in y direction). all i need it how can i get the velocity of 13 interest points from this matrix flow so finally i must have

> > > x y v(x) v(y)

> > > 72. 46.7543 0.087396 -0.135287

> >

> > Using x and y as indexes in a matrix requires them to be integers ...

> >

> > Your question is also not very clear. You have "another matrix called flow" which is 2D but you index a one-dimensional vector v, using v(x) and v(y).

> >

> > Please rephrase ...

> >

> > ~ Jos

>

> it's not one dimensional vector it will be 13 rows and 4 coulmns , i written one row as example (location of points and their velocities)

in matlab v(x) means "the value of v at position (=index) x".

Perhaps you can give a very brief example of what you want to achieve with two points (= two x and y values) and a flow matrix which is, let's say, 3 by 4? It would be very helpful if you show the exact inputs and desired outputs.