An issue with the partition coefficient calculation

[OjasArnav]

for a given no. of clusters c, the value of partition clusters should be in the range [1/c,1] according to the research paper you linked, however here for c=2, I get:

which is clearly less than c=1/2=0.5

is there something wrong here?

[mariohopfner]

From where I see it, this might be a problem with the calculation of the PC and the PEC values.
Both calculations should be made as np.sum(np.mean(..., axis=0)) instead of just np.mean(...).
I have suggested a fix for that in PR #108. @omadson Please have a look if my assumption is correct.