[Eeglablist] eegplot() GUI scale

[Makoto Miyakoshi]

Dear Bethel,

Sorry for the trouble.

> When I open the recording the eegplot just snap to certain
scale which do not necessary allow me to correctly visualise the data
amplitude. Using the  +- buttons to change the scale does not have any
effect.

My initial guess is that the data have huge DC drift.
Try this: in eegplot() GUI, in the top tab, [Display] -> [Remove DC offset].

> This could be because the amplitude in some channels are very high
compared with others.

Even if amplitude is high, as long as they are AC they should frequently
cross the zero line, hence I guessed DC offset is present. If you recorded
the data without using high-pass filter... DC drift could be up to 10,000
uV. High-pass filter removes it as well. Try these solutions and let me
know if it works.

Makoto

On Thu, Jul 12, 2018 at 10:32 AM Bethel Osuagwu <bethel.osuagwu at gmail.com>
wrote:

> Dear All,
> I posted this some time ago and had no response; I am posting again
> because I think this could be a bug.
>
> I am using EEGLAB(v13.5.4b) to process data and am struggling to scale
> trace
> amplitudes. When I open the recording the eegplot just snap to certain
> scale which do not necessary allow me to correctly visualise the data
> amplitude. Using the  +- buttons to change the scale does not have any
> effect. Also using the input field to change the scale does not work as the
> input field only snap to certain values. This could be because the
> amplitude in some channels are very high compared with others. I keep
> having to plot the data using matlab plot in other to visualise it.
>
> How can I change the scale to any arbitrary value so to see the trace
> amplitudes nicely?
>
> Thanks
>
>
> --
> *Bethel A. C. Osuagwu*
> Clinical Research Fellow
>
> *Stoke Mandeville Spinal Research*
> National Spinal Injuries Centre
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> Tel: 01296 31 5963 (Applied NeuroLab)
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-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
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