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<p class="MsoNormal"><span lang="FR-CH">Dear Fieldtrippers,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CH"><o:p> </o:p></span></p>
<p class="MsoNormal">I am trying to implement the example provided here (<a href="http://www.fieldtriptoolbox.org/tutorial/fourier/">http://www.fieldtriptoolbox.org/tutorial/fourier/</a>) to measure the phase synchronization between two signals. I followed
the paragraph starting by “The coherence spectrum”.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">From what I understand of the “Coherence spectrum” example script of this web-page, the plot that one should obtain when calling
<i>plot(coh)</i> is a 2-D plot with the y-axis corresponding to the coherence index between 0 to 1 and x-axis corresponding to frequencies (right ?).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">However, when I changed the length of the signal (argument “<i>len</i>”), I noticed that the frequency (x-) axis increased by the same factor (e.g. if I change
<i>len</i> from 1 to 2.5, the x-axis changes from 100 to 250). The coherence is no more on 10 Hz, but on 25 Hz. I must have missed something simple, but I do not understand why the results (& frequency axis) depend on the duration of the signal ? Did I miss
a normalization somewhere ?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any help would be greatly appreciated !<o:p></o:p></p>
<p class="MsoNormal">Thanks in advance !<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">-----------------------------<br>
Dr. Laurent Sheybani, Ph.D<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">Médecin interne en Neurologie Clinique<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">Clinique de Neurologie<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">Hôpitaux Universitaires de Genève<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">Rue Gabrielle-Perret-Gentil, 4<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">1205 Genève<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-family:"Times New Roman",serif;mso-fareast-language:EN-GB">Switzerland<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CH"><o:p> </o:p></span></p>
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