bodhisattwa-chakraborty / dmfa07 Goto Github PK

hi, I need your help.

I have downloaded your code DBSCAN.M and has renamed it in dbscan.m to use the 
code in Octave because I don't have Matlab.
Now I want to use the code on a dataset with 8 objects having 2 attributes. My 
file sees like that :
    1  2
    2  3
    4  5
    2  1
    3  4
    2  2
    1  3
    5  5
I think that this is the right codage for the file but when i will use your 
clusteringfigs as mention in your example, i receive always an error saying 
'clusteringfigs' undefined.

Can you help me and say me where the problems lies and how i can fix it?

Thanks

Suppose I have a vector

y = [1 2 1 2 5].

Then, there obviously is a group of 4 in the first 4 elements of the vector 
using, say, eps = 1. 

However, running 

> dbscan(y', 4, 1)
ans =

    -1    -1    -1    -1    -1

which is clearly not what is intended. However, the following works:

> dbscan(y', 3, 1)
ans =

    1    1    1    1    -1

Suppose we have the vector

y = [1 1 1 2 3 4]

Then, with eps = 1 and k = 4 we clearly expect that 3 to be on the boundary of 
the group formed by [1 1 1 2]. By algorithm definition, 3 is not allowed to 
propagate group membership. However, we find that

>> [a,b] = dbscan(y', 3, 1)

a =

     1     1     1     1     1     1


b =

     1     1     1     1     0     0


where 3 did propagate the group membership to 4. 4 However should be classified 
as an outlier. (Note that I entered k-1 to dbscan, as explained in my other bug 
report.