How can i calculate the distance to all data points?

I basically want to start at one data point and then calculate the distance to all the other points. Then i want to select the nearest 15. Im not really sure where to start if i'm honest. If someone can point me in the right direction it would be much appreciated

Answer 1

[Matt J]

These look relevant

http://www.mathworks.com/matlabcentral/fileexchange/18937-ipdm-inter-point-distance-matrix

http://www.mathworks.com/matlabcentral/fileexchange/19345

Answer 2

[Thomas]

If you have the statistics toolbox this might help

http://www.mathworks.com/help/stats/pdist.html

There is also a file exchange contribution which might help

http://www.mathworks.com/matlabcentral/fileexchange/71

Answer 3

[Azzi Abdelmalek]

    f1=@(x,y,x0,y0) sqrt((x-x0).^2+(y-y0).^2)

%how to call f1

 x=1:100 % example
 y=randi(100,1,100)
 x0=x(4); y0=y(4)  % start point
 dist=f1(x,y,x0,y0)
 [out,idx]=sort(dist)
 res=out(2:16)   % 15 first distances
 res_idx=idx(2:16) % corresponding index