[FieldTrip] ft_rejectvisual problem

[Robert Oostenveld]

Hi Ozan

The error suggests that the variance that is computed is either 0, or is nan. A zero variance could be the cause of a channel that is clipping. The consequence of that is that the scaling of the vertical axis cannot be determined correctly.

Using the following code

data = []
data.label = {'a'}
data.time = {1:1000};
data.trial = {zeros(1,1000)};

cfg = [];
ft_rejectvisual(cfg, data)

I was able to reproduce your error. I only have a single all-zero channel (and one trial), but it suggests that your data is all zero. I suggest you check your data with ft_databrowser or standard MATLAB plotting functions.

The error of ft_rejectvisual however should not occur, so I have filed it on our bug tracking system as http://bugzilla.fcdonders.nl/show_bug.cgi?id=2450

If you want to keep track of the bug and be notified when we fix it, please register at bugzilla.fcdonders.nl and add yourself as CC to the bug.

best regards and thanks for reporting the issue,
Robert



On 22 Jan 2014, at 14:07, Ozan Çağlayan wrote:

> Hi,
> 
> When I call ft_rejectvisual, I receive the following matlab error:
> 
>>> [data] = ft_rejectvisual(cfg, data)
> the input is raw data with 14 channels and 1 trials
> showing a summary of the data for all channels and trials
> computing metric [--------------------------------------------------------|]
> Error using set
> Bad property value found.
> Object Name: axes
> Property Name: 'XLim'
> Values must be increasing and non-NaN.
> 
> Error in axis>LocSetLimits (line 201)
>    set(ax,...
> 
> Error in axis (line 93)
>                LocSetLimits(ax(j),cur_arg);
> 
> Error in rejectvisual_summary>redraw (line 252)
> abc = axis; axis([1 info.ntrl abc(3:4)]);
> 
> Error in rejectvisual_summary (line 126)
>    redraw(h);
> 
> Error in ft_rejectvisual (line 274)
>  [chansel, trlsel, cfg] = rejectvisual_summary(cfg, tmpdata);
> 
> --------
> 
> my cfg is empty. Data is a one trial x 14 channel EEG data. The visual
> rejection GUI appears but when I change the metric the figures in the
> GUI are not redrawn. Is this expected? Is the above error important?
> This is Matlab 2013a on Linux with the latest FieldTrip from GIT.
> 
> Thanks.
> 
> -- 
> Ozan Çağlayan
> Research Assistant
> Galatasaray University - Computer Engineering Dept.
> http://www.ozancaglayan.com
> 
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