<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear all,<div class=""><br class=""></div><div class="">I asked this question but I did not receive a response yet:</div><div class=""><br class=""><div><div class=""><blockquote type="cite" class="">I computed the debiased weighted phase lag index for all channel combinations of a 30-channel EEG resting state recording. The output file (wpli_debiasedspctrm) has the following dimensions (435x30). I subsequently averaged the file across the second dimension to get an average debiased wpli estimate across the frequency band of interest. Now, I want to put this estimate into an adjacency matrix format (30x30) so I can illustrate the connectivity matrix using e.g. imagesc in Matlab. Is there a way I can achieve this in fieldtrip? <br class=""></blockquote><div class=""><br class=""></div>I tried a few approaches in the mean time but I cannot seem to get the results I want. Using a 30-channel EEG recording, I expect a 900x30 output variable corresponding to wpli values for all possible channel combinations (even identical ones) per frequency in both directions (e.g. Cz-Fz and Fz-Cz). I tried to achieve this using f<span style="white-space: pre;" class="">t_channelcombination and although this yields the correct channel combinations, it doesn’t change the wpli output. Looking into the code</span></div><div class=""><span style="white-space: pre;" class="">I found that this is probably due to the fact that my data is bivariate and the code states that „</span><span style="white-space: pre;" class=""><span style="color: rgb(0, 128, 19);" class=""> This only has an effect when </span></span><span style="color: rgb(0, 128, 19); white-space: pre;" class="">the input data</span></div><div class=""><span style="color: rgb(0, 128, 19); white-space: pre;" class="">is univariate</span><span style="white-space: pre;" class="">“. </span></div><div class=""><span style="white-space: pre;" class=""><br class=""></span></div><div class=""><span style="white-space: pre;" class="">Here is the code I’ve used so far:</span></div><div class=""><span style="white-space: pre;" class=""><br class=""></span></div><div class=""><div class="rtcContent"><div class="lineNode"></div><blockquote type="cite" class=""><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class="">% Define the resampling parameters</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg = [];</span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.resamplefs = 125; </span></div><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class=""><br class=""></span></span></div><div class="lineNode"><!--[if mso]><br><![endif]--></div><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class="">% Resample the data</span></span></div><div class="lineNode"><span style="white-space: pre" class="">ft_data_rs = ft_resampledata(cfg, ft_data);</span></div><div class="lineNode"><span style="white-space: pre" class=""><br class=""></span></div><div class="lineNode"><!--[if mso]><br><![endif]--></div><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class="">% Cut data into multiple trials</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg = [];</span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.length = 1; <span style="color: rgb(0, 128, 19);" class="">% 1 sec. segments</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.overlap = 0;</span></div><div class="lineNode"><span style="white-space: pre" class="">ft_data_rs_seg = ft_redefinetrial(cfg, ft_data_rs);</span></div><div class="lineNode"><span style="white-space: pre" class=""><br class=""></span></div><div class="lineNode"><!--[if mso]><br><![endif]--></div><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class="">% Freq analysis I</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg = [];</span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.method = <span style="color: rgb(167, 9, 245);" class="">'mtmfft'</span>; <span style="color: rgb(0, 128, 19);" class="">% use multitaper frequency transformation </span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.output = <span style="color: rgb(167, 9, 245);" class="">'powandcsd'</span>; <span style="color: rgb(0, 128, 19);" class="">% compute power spectrum and cross-spectral density</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.taper = <span style="color: rgb(167, 9, 245);" class="">'dpss'</span>; <span style="color: rgb(0, 128, 19);" class="">% use DPSS taper window </span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.foi = 1:30; <span style="color: rgb(0, 128, 19);" class="">% frequency range of interest</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.keeptrials = <span style="color: rgb(167, 9, 245);" class="">'yes'</span>; <span style="color: rgb(0, 128, 19);" class="">% average over trials</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.channel = <span style="color: rgb(167, 9, 245);" class="">'all'</span>; <span style="color: rgb(0, 128, 19);" class="">% use all channels</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.trials = <span style="color: rgb(167, 9, 245);" class="">'all'</span>; <span style="color: rgb(0, 128, 19);" class="">% use all trials</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.tapsmofrq = 8; <span style="color: rgb(0, 128, 19);" class="">% specify the smoothing parameter for DPSS</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.pad = <span style="color: rgb(167, 9, 245);" class="">'nextpow2'</span>; <span style="color: rgb(0, 128, 19);" class="">% should increase computation speed </span></span></div><div class="lineNode"><!--[if mso]><br><![endif]--></div><div class="lineNode"><span style="white-space: pre" class="">freq=ft_freqanalysis(cfg,ft_data_rs_seg);</span></div><div class="lineNode"><br class=""></div><div class="lineNode"><!--[if mso]><br><![endif]--></div><div class="lineNode"><span style="white-space: pre" class=""><span style="color: rgb(0, 128, 19);" class="">% Define the connectivity parameters</span></span></div><div class="lineNode"><span style="white-space: pre" class="">cfg = [];</span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.method = <span style="color: rgb(167, 9, 245);" class="">'wpli_debiased'</span>; </span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.channelcmb = {<span style="color: rgb(167, 9, 245);" class="">'all' </span><span style="color: rgb(167, 9, 245);" class="">'all'</span>};</span></div><div class="lineNode"><span style="white-space: pre" class="">cfg.complex = <span style="color: rgb(167, 9, 245);" class="">'abs'</span>;</span></div><div class="lineNode"><br class=""></div><div class="lineNode"><span style="white-space: pre" class="">wpli_data = ft_connectivityanalysis(cfg, freq);</span></div></blockquote></div></div><div class=""><span style="white-space: pre;" class=""><br class=""></span></div><div class=""><span style="white-space: pre;" class="">To summarize: I would like to compute debiased wpli for all channels (even identical ones) in both directions. Further, I would like to store </span></div><div class=""><span style="white-space: pre;" class="">the debiased wpli output in a 30x30 adjacency/connectivity matrix. </span></div><div class=""><span style="white-space: pre;" class=""><br class=""></span></div><div class=""><span style="white-space: pre;" class="">As I am still quite new to FieldTrip I am stuck here and I would really appreciate your help on this issue.</span></div><div class=""><br class="">Thanks in advance and all the best,<br class=""><br class="">Tyler </div></div><br class=""></div></body></html>