Chi-square distance formula

Considering I'm using euclidean distance to calculate the distance between two vector.

cosined=sqrt(sum(abs((a-b).^2)))

Now I want to change euclidean into chi-square distance, does anyone know how to calculate chi-square distance between two vectors?

[Manolis Michailidis]

take a look here http://www.mathworks.com/matlabcentral/newsreader/view_thread/300450

[Js Goh]

tested, not working

Answer 1

[the cyclist]

I found this page after googling for about 30 seconds: http://www.cs.columbia.edu/~mmerler/project/code/pdist2.m

[Js Goh]

i found this too but I don't know how to modify it w/o the loop.

Sry I'm too new to matlab, still learning.

[Manolis Michailidis]

i recommend you first use it as it is with thhe loop to see if you get the expected results

[Js Goh]

I tried, it doesn't come out with the expected results.

[the cyclist]

I don't understand what you about the loop. I just put that function in a directory, then did

pdist2([1 2 3],[4 5 6],'chisq')

and got a result. What more do you need?

[AJAY KUMAR SAHU]

Hey, It doesn't work!!

[the cyclist]

MATLAB has a built-in pdist2 function, which you are presumably calling (rather than the one from the link listed above). You have two options:

• Download the function from the link above, and use it
• Use the built-in MATLAB function, which has the ability to define a custom distance function, and code the chi-square distance yourself.