<div dir="ltr"><div><div><div>Hi Christine,<br><br></div>take a look into the cfg.previous of ERDERS. Fieldtrip stores information on previous data analysis steps there. Maybe the trial information is hidden somewhere in there.<br></div><div>The MatLab command rmfield can then be used to remove some unwanted fields from a structure. But please beware! There is a good reason for the thorough bookkeeping in Fieldtrip (which has saved me quite often).<br></div>Good luck,<br><br></div>Julian<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Nov 30, 2016 at 10:25 AM, Blume Christine <span dir="ltr"><<a href="mailto:christine.blume@sbg.ac.at" target="_blank">christine.blume@sbg.ac.at</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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<p class="MsoNormal">Dear Community,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span lang="EN-US">I have an issue with data size. I am processing high-density EEG data from a sleep study. Following preprocessing I perform time-frequency transformations and a baseline correction using the following code:
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg = [];</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.method =
</span><span style="font-size:10.0pt;font-family:"Courier New";color:#a020f0" lang="EN-US">'wavelet'</span><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US">;</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.output =
</span><span style="font-size:10.0pt;font-family:"Courier New";color:#a020f0" lang="EN-US">'pow'</span><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US">;</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.keeptrials =
</span><span style="font-size:10.0pt;font-family:"Courier New";color:#a020f0" lang="EN-US">'no'</span><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US">;</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.width = 3;
</span><span style="font-size:10.0pt;font-family:"Courier New";color:forestgreen" lang="EN-US">%
</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.foi = 1:1:16;
</span><span style="font-size:10.0pt;font-family:"Courier New";color:forestgreen" lang="EN-US">%
</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.toi = -0.7:0.2:0.9;
</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> freqanalysis_FV = ft_freqanalysis(cfg, data_FV);<u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg = [];</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.baseline = [-0.6, 0];
</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> cfg.baselinetype =
</span><span style="font-size:10.0pt;font-family:"Courier New";color:#a020f0" lang="EN-US">'relchange'</span><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US">;</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New";color:black" lang="EN-US"> ERDERS_FV = ft_freqbaseline(cfg, freqanalysis_FV)</span><span style="font-size:12.0pt;font-family:"Courier New"" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">As you can see, I do <b>not</b> keep the trials. Still, the size of ERDERS seems to depend on the size of data_FV. Why is that the case? Also, changing cfg.foi does not change the file size – why? The problem is that
this way the data can hardly be handled as it takes up so much RAM. Please note that I do clear everything from the workspace I do not need, that should not be the issue.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks a lot for your thoughts.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Best,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Christine<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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