<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Dear Arti,<div>the units on the tutorial are in Tesla^2. In your case they might end up being in V^2 if you first convert them to volts instead of bits, i.e. the reason why you end up with those high values.</div><div>So, to your question, your are not doing anything wrong.</div><div>best </div><div>tzvetan</div><div><br><div><blockquote type="cite"><div dir="ltr">Thanks Peter. Perhaps I wasn't clear in the previous email. The time frequency values that I got are too high. I had to changes the Z axis limits to -500 to 500 instead of the <span style="font-family: Consolas, 'Andale Mono', Menlo, Monaco, monospace; font-size: 12px; text-align: justify; white-space: pre-wrap; background-color: rgb(247, 249, 250);">[-3e-27 3e-27] </span><span style="font-size: 12px; text-align: justify; white-space: pre-wrap; background-color: rgb(247, 249, 250);"><font face="arial, helvetica, sans-serif">values on the tutorial. Is there anything I am doing wrong?</font></span><div><span style="font-size: 12px; text-align: justify; white-space: pre-wrap; background-color: rgb(247, 249, 250);"><font face="arial, helvetica, sans-serif">Thanks</font></span></div><div><span style="font-size: 12px; text-align: justify; white-space: pre-wrap; background-color: rgb(247, 249, 250);"><font face="arial, helvetica, sans-serif">Arti</font></span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 13, 2014 at 8:41 PM, Peter Goodin <span dir="ltr"><<a href="mailto:pgoodin@swin.edu.au" target="_blank">pgoodin@swin.edu.au</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div style="direction: ltr; font-family: Tahoma; font-size: 10pt;">Hi Arti,
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<div>Try lowering the cfg.zlim values (<span style="color: rgb(34, 139, 34); font-family: 'Courier New'; font-size: 12px;">%% Plot TFR</span><font>). </font></div>
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<div><font>Peter<br>
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<div style="font-family:Tahoma;font-size:13px"><font>__________________________</font></div>
<div><font style="font-family:Tahoma;font-size:13px">Peter Goodin, </font>
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<div style="font-family:Tahoma;font-size:13px">BSc (Hons), Ph.D Candidate.</div>
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<div style="font-family:Tahoma;font-size:13px"><font>Brain and Psychological Sciences Research Centre (BPsych)</font></div>
<div style="font-family:Tahoma;font-size:13px">Swinburne University, </div>
<div style="font-family:Tahoma;font-size:13px">Hawthorn, Vic, 3122</div>
<div><a href="http://www.swinburne.edu.au/swinburneresearchers/index.php?fuseaction=profile&pid=4149" target="_blank">http://www.swinburne.edu.au/swinburneresearchers/index.php?fuseaction=profile&pid=4149</a><br>
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<div style="font-family:Tahoma;font-size:13px"><font>Monash Alfred Psychiatry Research Centre (MAPrc)</font></div>
Level 4, 607 St Kilda Road, <br>
Melbourne 3004</div>
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<div style="direction:ltr"><font face="Tahoma"><b>From:</b> <a href="mailto:fieldtrip-bounces@science.ru.nl" target="_blank">fieldtrip-bounces@science.ru.nl</a> [<a href="mailto:fieldtrip-bounces@science.ru.nl" target="_blank">fieldtrip-bounces@science.ru.nl</a>] on behalf of Arti Abhishek [<a href="mailto:mailtome.2113@gmail.com" target="_blank">mailtome.2113@gmail.com</a>]<br>
<b>Sent:</b> Monday, 13 October 2014 5:49 PM<br>
<b>To:</b> <a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a><br>
<b>Subject:</b> [FieldTrip] Scaling issues with EEG time frequency analysis<br>
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<div>Dear fieldtrip users,</div>
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<div>I am a new fieldtrip user and I am having some problems with frequency analysis. My EEG data is recorded from Neuroscan NuAmps system (22 bit). I have used the following script (I wrote the script from the examples on the fieldtrip website), but I get
the time frequency plots with huge values. Could anyone please suggest me what I am doing wrong?</div>
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<div>Thanks</div>
<div>Arti<br>
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<div><font face="Courier New"><p>cfg =[];</p>
</font><p><font face="Courier New">cfg.dataset = </font><font color="#a020f0" face="Courier New">'s01.cnt'</font><font face="Courier New">;</font></p>
<font face="Courier New"><font face="Courier New"></font></font><p><font face="Courier New">cfg.channel = {</font><font color="#a020f0" face="Courier New">'all'</font><font face="Courier New">};</font></p>
<font face="Courier New"><font face="Courier New"></font></font><p><font face="Courier New">cfg.layout = </font><font color="#a020f0" face="Courier New">'NuAmps.lay'</font><font face="Courier New">;</font></p>
<font face="Courier New"><p>lay = ft_prepare_layout(cfg);</p>
</font><font color="#228b22" face="Courier New"><p>% Event identification</p>
</font><font face="Courier New"><font face="Courier New"></font></font><p><font face="Courier New"><font face="Courier New">cfg.trialdef.eventtype = </font>
</font><font color="#a020f0" face="Courier New">'trigger'</font><font face="Courier New">;</font></p>
<font face="Courier New"><p>cfg.trialdef.eventvalue = 101;</p><p>cfg.trialdef.prestim = 1;</p><p>cfg.trialdef.poststim = 2;</p>
</font><p><font face="Courier New">cfg.reref = </font><font color="#a020f0" face="Courier New">'yes'</font><font face="Courier New">;</font></p>
<font face="Courier New"><font face="Courier New"></font></font><p><font face="Courier New">cfg.implicitref = </font><font color="#a020f0" face="Courier New">'A1'</font><font face="Courier New">;</font></p>
<font face="Courier New"><font face="Courier New"></font></font><p><font face="Courier New">cfg.refchannel = {</font><font color="#a020f0" face="Courier New">'A1'</font><font face="Courier New"><font face="Courier New">
</font></font><font color="#a020f0" face="Courier New">'A2'</font><font face="Courier New">};</font></p>
<font face="Courier New"><p>cfg = ft_definetrial(cfg);</p>
</font><font color="#228b22" face="Courier New"><p>% % Filtering</p><p>% cfg.hpfilter = 'yes';</p><p>% cfg.hpfreq = 0.1;</p><p>% cfg.hpfilttype = 'fir';</p>
</font><font face="Courier New"><font face="Courier New"><p>dataFIC = ft_preprocessing(cfg);</p>
<font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><p>%% Summary detection of bad trials</p>
</font></font></font><font face="Courier New"><font face="Courier New"><p>cfg = [];</p>
</font></font><p><font face="Courier New"><font face="Courier New">cfg.method = </font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'summary'</font></font></font><font face="Courier New"><font face="Courier New">;</font></font></p><p><font face="Courier New"><font face="Courier New"></font></font><font face="Courier New"><font face="Courier New">cfg.layout = lay;
</font></font><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New">% this allows for plotting</font></font></font></p>
<font face="Courier New"><font face="Courier New"><p>cfg.channels = [1:34]; </p><p>data_clean = ft_rejectvisual(cfg, dataFIC);</p>
<font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><p>% Calculate TFR for condition1</p>
</font></font></font><font face="Courier New"><font face="Courier New"><p>cfg = [];</p><p>cfg.trials = find(data_clean.trialinfo==101);</p>
</font></font><p><font face="Courier New"><font face="Courier New">cfg.channel = </font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'EEG'</font></font></font><font face="Courier New"><font face="Courier New">;
</font></font></p><p><font face="Courier New"><font face="Courier New"></font></font><font face="Courier New"><font face="Courier New">cfg.method =
</font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'wavelet'</font></font></font><font face="Courier New"><font face="Courier New">;
</font></font></p>
<font face="Courier New"><font face="Courier New"><p>cfg.width = 7; <br>
</p>
</font></font><p><font face="Courier New"><font face="Courier New">cfg.output = </font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'pow'</font></font></font><font face="Courier New"><font face="Courier New">; </font></font></p>
<font face="Courier New"><font face="Courier New"><p>cfg.foi = 2:2:48; </p><p>cfg.toi = -0.5:0.05:1; </p><p>s01_TFRwave4ch = ft_freqanalysis(cfg, data_clean);</p>
<font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><p>%% Plot TFR</p>
</font></font></font><font face="Courier New"><font face="Courier New"><p>cfg = [];</p><p>cfg.baseline = [-0.5 -0.1]; </p>
</font></font><p><font face="Courier New"><font face="Courier New">cfg.baselinetype = </font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'absolute'</font></font></font><font face="Courier New"><font face="Courier New">;
</font></font></p>
<font face="Courier New"><font face="Courier New"><p>cfg.zlim = [-500 500];<br>
</p>
</font></font><p><font face="Courier New"><font face="Courier New">cfg.showlabels = </font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'yes'</font></font></font><font face="Courier New"><font face="Courier New">; </font></font></p>
<font face="Courier New"><font face="Courier New"><p>cfg.layout = lay;</p><p>figure</p><p>ft_multiplotTFR(cfg, s01_TFRwave4ch)</p>
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