[FieldTrip] help with topoplot_TFR

[Tzvetan Popov]

Dear Payashi,

you could compute the ratio per sample point and write it for example in ratiodata.avg= ratio. Where ratio is a chan_time matrix. Then you could type ratiodata.label = freq_continuous.label; ratiodata.dimord = ‘chan_time’. Next, you can use ft_multiplotER which handles time domain data where cfg.xlim is the option you need in order to plot the ratio topography for a particular time point. Is this what you need?
good luck
tzvetan


> Dear Fieldtrip community, 
> 
> My name is Payashi Garry and I am working in the Nuffield Department of Clinical Neurosciences in the University of Oxford. I am analysing some continuous EEG data that we have measured from our Neuro-Intensive Care unit patients. We are interested in using quantitative EEG measures to assess whether these can be used to detect cerebral ischaemia.
> 
> I have performed time frequency analysis using ft_freqanalysis. I have then been usig ft_topoplotTFR to visualise the results with no problems. However, one of the parameters we are investigating is the change in alpha/delta ratio. I was wondering if it would be possible to create topographic maps of the alpha/delta ratio for a particular time period (i.e. alpha power/delta power) using ft_topoplotTFR? 
> 
> At the moment I am generating topographic maps for alpha and delta power using the following commands:
> 
> cfg=[];
> cfg.baselinetype = 'absolute';
> cfg.xlim = [10 2500];
> cfg.ylim = [1 4];
> cfg.zlim = [0 100];
> cfg.colorbar = 'yes';
> figure
> ft_topoplotTFR(cfg, freq_continuous)
> title('delta power prenitrite', 'FontSize', 36, 'FontName', 'Arial')
> 
> with freq_continuous being my time/frequency/channel data. 
> 
> I would be very grateful for any advice on this, and would be happy to supply more information if needed. 
> 
> Many thanks
> Best wishes
> Payashi
> 
> ****
> Dr Payashi Garry MB BChir FRCA
> Specialty Registrar in Anaesthetics and BRC Research Fellow
> Nuffield Department of Clinical Neurosciences
> John Radcliffe Hospital
> Oxford OX3 9DU
> Tel: 01865 572878
> 
> 
> 
> _______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip