<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Mary-Jane,<div><br></div><div>there is a solution to do this in the graphic interface (menu item "Plot > Sum/compare ERPs). Then you may check the option to subtract conditions. </div><div><br></div><div>At the STUDY level, it is currently not possible to plot differences using the graphic interface. However, plotting differences from the command line is pretty easy. For example, after creating a STUDY and pre-computing ERP, you may calls the function that plots ERP in STUDY (assumes 2 conditions) on channel 'cz' (I copied the first line from the EEGLAB history)</div><div><br></div><div>[STUDY erpdata erptime]= std_erpplot(STUDY,ALLEEG,'channels',{'CZ'});</div><div>figure;</div><div><div>plot(erptime, mean(erpdata{1},2), 'r'); % plot first condition in red</div></div><div><div><div><div>plot(erptime, mean(erpdata{2},2), 'b'); % plot second condition in red</div></div></div></div><div><div><div>plot(erptime, mean(erpdata{2},2)-mean(erpdata{1},2), 'k-'); % plot difference in black dashed</div></div></div><div><br></div><div>That's it. Note that this is what erpdata contains</div><div><br></div><div><div>erpdata = </div><div><div><br></div><div> [750x12 double]</div><div> [750x12 double]</div></div><div><br></div><div>It is 12 subjects 750 points and 2 conditions.</div></div><div>Best,</div><div><br></div><div>Arno</div><div><br><div><div>On 23 Aug 2013, at 19:46, Makoto Miyakoshi wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><div dir="ltr">Dear Mary-Jane,<div><br></div><div>The default EEGLAB does not have a solution for it.</div><div><br></div><div>If you are trying to plot IC ERP and not channel ERP, please try my plugin (alpha version). Note this plugin is for STUDY level, but you can create STUDY with n=1. Unzip it and locate the folder under /eeglab/plugins and reboot eeglab.</div>
<div><br></div><div>I haven't tried it personally, but ERPLAB may do it.</div><div><a href="http://erpinfo.org/erplab">http://erpinfo.org/erplab</a></div><div><br></div><div>Sometimes something very fundamental is missing from EEGLAB... </div>
<div><br></div><div>Makoto</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/8/22 Budd, Mary-Jane S <span dir="ltr"><<a href="mailto:mbudd@essex.ac.uk" target="_blank">mbudd@essex.ac.uk</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear List,<br>
I would like some help on plotting difference waves. I would like to plot<br>
the difference of two conditions (C1 minus C2) and plot this difference wave<br>
on the same plot as the difference of two other conditions (A1 minus A2).<br>
Could someone tell me how to do this through the EEGlab GUI?<br>
Thank you,<br>
Mary-Jane<br>
<br>
----------------------<br>
Dr Mary-Jane Budd<br>
Senior Research Officer<br>
Department of Psychology<br>
University of Essex<br>
Wivenhoe Park<br>
Colchester CO4 3SQ<br>
UK<br>
<br>
Room 4.726<br>
<br>
<a href="http://www.essex.ac.uk/psychology/department/people/Budd.html" target="_blank">http://www.essex.ac.uk/psychology/department/people/Budd.html</a><br>
<br>
<br>
_______________________________________________<br>
Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" target="_blank">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>
To unsubscribe, send an empty email to <a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>
For digest mode, send an email with the subject "set digest mime" to <a href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a><br>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br></div>
</div>
<span><std_erpcalc.zip></span>_______________________________________________<br>Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>To unsubscribe, send an empty email to <a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>For digest mode, send an email with the subject "set digest mime" to <a href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a></blockquote></div><br></div></body></html>