29.04.2013 Views

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

solutions).<br />

F.11 PenDigits data set<br />

Appendix F. Experiments on soft consensus clustering<br />

The results of the soft consensus clustering experiments conducted on the PenDigits data<br />

set are described in the following paragraphs. Due to the number of objects n contained in<br />

this collection, the CSPA and EAC consensus functions were not executable –as their space<br />

complexity scales quadratically with n.<br />

Thus, as a means for comparing the seven consensus functions applied on this data set,<br />

figure F.11 depicts the φ (NMI) vs CPU time mean ± 2-standard deviation regions corresponding<br />

to them. It can be observed that, in this case, the four voting based consensus<br />

functions proposed are the most time consuming. However, those based on confidence voting<br />

(PC and SC) are relatively comparable to HGPA and MCLA, while BC and CC are the<br />

most computationally costly (especially the latter). As in the previous cases, VMA is the<br />

most efficient of the consensus functions compared.<br />

When comparison is referred to the φ (NMI) of the consensus clustering solutions yielded<br />

by the seven consensus functions, we can observe that the highest quality is obtained by PC<br />

and SC, which match VMA in this aspect. The other two voting based consensus functions<br />

(BC and CC) perform slightly worse, but far better than MCLA and HGPA.<br />

385

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!