'lo, again! On Mon, Apr 15, 2013 at 6:16 PM, Yaroslav Halchenko <[email protected]> wrote: > > On Mon, 15 Apr 2013, Paul Robinson wrote: > >> Hi, Yaroslav. > >> As follows: > >> >>> print fds.summary() >> Dataset: 39x172800@float32, <sa: >> chunks,targets,time_coords,time_indices>, <fa: voxel_indices>, <a: >> imghdr,imgtype,mapper,voxel_dim,voxel_eldim> >> stats: mean=-0.00263811 std=0.566497 var=0.320918 min=-5.24132 max=5.29731 >> No details due to large number of targets or chunks. Increase maxc and >> maxt if desired >> Summary for targets across chunks >> targets mean std min max #chunks >> Control 0.513 0.5 0 1 20 >> Patient 0.487 0.5 0 1 19 > > I suspect that you have placed each sample into a unique chunk > (where they could actually rightfully belong since this is different > subjects).
Yes, this is what I intended, so good to know I'm on the right track here. > Then with N-Fold partitioning you are pretty much doing > leave-1-out. Hence your errors would be either 0 or 1 since you have > only 1 sample you cross-validate into. Here, too, I was going for leave-one-out, but didn't realize that would lead to errors of 0 or 1...guess I thought the imbalance would affect that.... :/ > > print cvte.ca.stats > > should give you a better "picture" Right. As I mentioned, this classifier is not doing so well. I get a confusion matrix something like: [[11, 13], [9, 6]] > > but mention that you have only few samples, and lots of features, and > disbalance between conditions, so classifier might just go for the one > with more samples to reduce error etc... > >> Sequence statistics for 39 entries from set ['Control', 'Patient'] >> Counter-balance table for orders up to 2: >> Targets/Order O1 | O2 | >> Control: 19 1 | 18 2 | >> Patient: 0 18 | 0 17 | >> Correlations: min=-0.95 max=0.9 mean=-0.026 sum(abs)=19 > > this is irrelevant here since this is independent samples > > > -- > Yaroslav O. Halchenko > http://neuro.debian.net http://www.pymvpa.org http://www.fail2ban.org > Senior Research Associate, Psychological and Brain Sciences Dept. > Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 > Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 > WWW: http://www.linkedin.com/in/yarik > > _______________________________________________ > Pkg-ExpPsy-PyMVPA mailing list > [email protected] > http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-exppsy-pymvpa Again, thanks for the input! Best, Paul _______________________________________________ Pkg-ExpPsy-PyMVPA mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-exppsy-pymvpa
