Error when using kmedoids with custom distance function

Hi,

I created a custom distance function which I used with linkage and it worked fine. Here is how I call it: Z = linkage(matrix_clean,'average','@new_dist');

When I try using kmedoids (from the stats toolbox) with a custom fucntion I get an error. Here is how I call the fucntion: [idx,C,sumd,d,midx] = kmedoids(matrix_clean,2,'Distance','@new_dist');

Here is the error:

Error using lower Not enough input arguments.

Error in kmedoids (line 242) distance = lower(methods{i});

How should I pass in my custom distance function in kmedoids?

Thanks,

Daniel

[Geoff Hayes]

Daniel - if this happens again, in the Command Window, type

 which lower -all

Perhaps you have a custom function named lower that requires more than one input parameter and so is causing some confusion with the built-in MATLAB lower function.

Answer 1

[Siddharth Sundar]

Within the kmedoids function, there is a check on the distance metric to see if it is a string or a function handle. In your case, you have entered the function handle as a string and hence it is following a different code path from the one it should be following. All you would need to to is to use the command without quotes around your function handle:

[idx,C,sumd,d,midx] = kmedoids(matrix_clean,2,'Distance',@new_dist);