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</o:shapelayout></xml><![endif]--></head><body lang=EN-MY link="#0563C1" vlink="#954F72"><p><span style="padding: 3px 10px; border-radius: 5px; color: #ffffff; font-weight: bold; display: inline-block; background-color: #ff0000;"> External Email - Use Caution </span></p><p></p><div class=WordSection1><p style='margin:0cm;margin-bottom:.0001pt'>While trying with the mne downsampling module, I encountered some behavior that I am unable to explain myself.<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>My understanding of downsampling is that it is an operation to decrease the sample rate of x by keeping the first sample and then every nth sample after the first.<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>The example provided from the resample method of scipy package clearly illustrated about this operation as depicted the picture which is accessible from the link (<a href="https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.resample.html)" target="_blank"><span style='color:windowtext'>https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.resample.html)</span></a> or as extracted below<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><img border=0 width=538 height=241 style='width:5.6041in;height:2.5104in' id="Picture_x0020_3" src="cid:image001.jpg@01D6612F.CC3BB2F0" alt="A close up of a map Description automatically generated"><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>In an enlarged view, it is evident that the original data points were resampled point by point.<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>However, using the mne example of downsampling which accessible via the link<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>: <a href="https://mne.tools/dev/auto_examples/preprocessing/plot_resample.html" target="_blank"><span style='color:windowtext'>https://mne.tools/dev/auto_examples/preprocessing/plot_resample.html</span></a><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>, I notice that the data points were not resampled point by point as illustrated visually below<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><img border=0 width=547 height=245 style='width:5.6979in;height:2.552in' id="Picture_x0020_4" src="cid:image002.png@01D6612F.CC3BB2F0" alt="A screenshot of a cell phone Description automatically generated"><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>This given that, mne resample is based on the resample method of scipy package as indicated from mne resample function as shown:<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><a href="https://github.com/mne-tools/mne-python/blob/607fb4613fb5a80dd225132a4a53fe43b8fde0fb/mne/filter.py#L1342" target="_blank"><span style='color:windowtext'>https://github.com/mne-tools/mne-python/blob/607fb4613fb5a80dd225132a4a53fe43b8fde0fb/mne/filter.py#L1342</span></a><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>May I know whether this issue is due to the ringing artifacts or due to other problems?<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>Also, are there remedies to mitigate this problem.<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>Thanks for any insight. Appreciate it<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>Cheers<o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'>Rodney<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>