[FieldTrip] ft_artifact_zvalue

[Vahab Yousofzadeh]

Dear FT experts,

Seems that the ft_artifact_zvalue only takes positive z-values to look
for artifacts:
https://www.dropbox.com/s/zbhslrn12j6ug7o/EOG_Artifacts.tif?dl=0

different than a sample figure in,
http://www.fieldtriptoolbox.org/tutorial/automatic_artifact_rejection/

Here are my settings:
cfg            = [];
cfg.continuous = 'yes';
cfg.artfctdef.zvalue.channel     = refchan;
cfg.artfctdef.zvalue.cutoff      = z_ther;
cfg.artfctdef.zvalue.trlpadding  = 0;
cfg.artfctdef.zvalue.artpadding  = 0.1;
cfg.artfctdef.zvalue.fltpadding  = 0;
cfg.artfctdef.zvalue.bpfilter   = 'yes';
cfg.artfctdef.zvalue.bpfilttype = 'but';
cfg.artfctdef.zvalue.bpfreq     = [1 15];
cfg.artfctdef.zvalue.bpfiltord  = 4;
cfg.artfctdef.zvalue.hilbert    = 'yes';
cfg.artfctdef.zvalue.interactive = interactive;
[~, artifact_EOG] = ft_artifact_zvalue(cfg, data);

Any comments are welcomed,
- Vahab