29.04.2013 Views

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

F.5. WDBC data set<br />

φ (NMI)<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

IONOSPHERE<br />

0<br />

0 0.5 1 1.5 2 2.5<br />

CPU time (sec.)<br />

CSPA<br />

EAC<br />

HGPA<br />

MCLA<br />

VMA<br />

BC<br />

CC<br />

PC<br />

SC<br />

Figure F.4: φ (NMI) vs CPU time mean ± 2-standard deviation regions of the soft consensus<br />

functions on the Ionosphere data collection.<br />

CSPA EAC HGPA MCLA VMA BC CC PC SC<br />

CSPA ——— 0.0001 0.0001 × 0.0001 0.0002 0.0002 × ×<br />

EAC 0.0001 ——— 0.0001 0.0001 0.0001 × × 0.0001 0.0001<br />

HGPA 0.0001 0.0001 ——— 0.0008 0.0001 0.0001 0.0001 0.0033 0.0031<br />

MCLA 0.012 0.0004 0.0492 ——— 0.0001 0.0009 0.0014 × ×<br />

VMA 0.0336 0.0001 0.0001 × ——— 0.0001 0.0001 0.0001 0.0001<br />

BC × 0.0001 0.0001 0.0002 0.0001 ——— × 0.0003 0.0003<br />

CC × 0.0001 0.0001 0.0002 0.0001 × ——— 0.0004 0.0004<br />

PC 0.0312 0.0001 0.0001 × × 0.0001 0.0001 ——— ×<br />

SC 0.0302 0.0001 0.0001 × × 0.0001 0.0001 × ———<br />

Table F.4: Significance levels p corresponding to the pairwise comparison of soft consensus<br />

functions using a t-paired test on the Ionosphere data set. The upper and lower triangular<br />

sections of the table correspond to the comparison in terms of CPU time and φ (NMI) ,<br />

respectively. Statistically non-significant differences (p >0.05) are denoted by the symbol<br />

×.<br />

in this data set –k = 2– does not penalize CondorcetConsensus), while EAC is the least<br />

efficient option.<br />

As far as the quality of the consensus clustering solutions is concerned, PC and SC get<br />

to match VMA as the best performing consensus functions, showing smaller dispersion in<br />

φ (NMI) terms than BC, CC and MCLA.<br />

If the statistical significance of the CPU time and φ (NMI) differences between consensus<br />

functions is evaluated –see table F.5– it can be observed that PC and SC are, in execution<br />

time terms, equivalent to CSPA and MCLA. As regards the quality of the consensus<br />

clustering solutions, no significant differences are observed between VMA, BC, CC, PC and<br />

SC, which, as aforementioned, turn out to be the best performing consensus functions.<br />

378

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

Saved successfully!

Ooh no, something went wrong!