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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dear Amr<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>There is no MEX implementation. I’m
quite sure (not 100% though, you could test with tic toc to be sure) that mtmconvol
is faster than wltconvol. I do have some tips to speed up the analysis though:<o:p></o:p></span></font></p>

<p class=MsoNormal style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><span style='mso-list:Ignore'>1)<font size=1 face="Times New Roman"><span
style='font:7.0pt "Times New Roman"'>       </span></font></span></span></font><![endif]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>make the timesteps smaller, for instance 0.05 sec in stead of 0.01 sec.
You have a time window of 0.5 second, so your actual time resolution is quite
limited anyway.<o:p></o:p></span></font></p>

<p class=MsoNormal style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><span style='mso-list:Ignore'>2)<font size=1 face="Times New Roman"><span
style='font:7.0pt "Times New Roman"'>       </span></font></span></span></font><![endif]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Do you really need a frequency resolution of 2 Hz? You could start
with 5 Hz frequency steps and increase the resolution if needed later.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hope this helps a bit,<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Ingrid<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>PS please don’t put my name above
the question so also others can feel free to answer the question. I don’t
mind answering questions (if they are well phrased and I happen to know the
answer such as in your case </span></font><font size=2 color=navy
face=Wingdings><span style='font-size:10.0pt;font-family:Wingdings;color:navy'>J</span></font><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>), but I also don’t mind if others do ;-)<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>

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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">FieldTrip discussion list</st1:PersonName>
[mailto:FIELDTRIP@NIC.SURFNET.NL] <b><span style='font-weight:bold'>On Behalf
Of </span></b>Amr Ayoub<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, August 17, 2009 1:38
PM<br>
<b><span style='font-weight:bold'>To:</span></b> FIELDTRIP@NIC.SURFNET.NL<br>
<b><span style='font-weight:bold'>Subject:</span></b> [FIELDTRIP] Re2:
[FIELDTRIP] freqanalysis_wltconvol variance</span></font><o:p></o:p></p>

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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>

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<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Dear Ingrid,<br>
<br>
The analysis is painfully slow; it would need weeks to finish. Is there a MEX
implementation of the time freq. analysis? Which is faster wltconvol or
mtmconvol?<br>
Below is the configuration of the time freq. analysis.<br>
<br>
   
cfg.sgn          = 'MEG';<br>
    cfg.method       =
'mtmconvol';   <br>
    cfg.output        =
'pow';<br>
   
cfg.foi          = 40:2:100 ;<br>
   
cfg.toi          = -1.4:0.01:1.4;<br>
    cfg.keeptrials='yes';<br>
    cfg.t_ftimwin    =
ones(length(cfg.foi),1).*0.5;   % length of time window = 0.5 sec<br>
    cfg.taper        =
'hanning';  <br>
    TFR = freqanalysis(cfg, TFA_slo_fz); <br>
<br>
vs<br>
<br>
    cfg.sgn         
= 'MEG';<br>
    cfg.method       = 'wltconvol
';<br>
    cfg.width        = 7;<br>
    cfg.output        =
'pow';<br>
   
cfg.foi          = 40:2:100 ;<br>
   
cfg.toi          = -1.4:0.01:1.4;<br>
    cfg.keeptrials='yes';<br>
    TFR = freqanalysis(cfg, TFA_slo_fz); <br>
<br>
Data configuration:<br>
Number of channels:151<br>
Sampling rate:250<br>
Number of trials:391<br>
<br>
PC configuration: Windows Vista Business SP1 64 bit - Intel Core 2 CPU 6320 @
1.86Ghz  1.86Ghz - RAM 4GB <o:p></o:p></span></font></p>

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<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Best regards,<br>
Amr<br>
<br>
<o:p></o:p></span></font></p>

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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Ingrid
Nieuwenhuis <ingrid.nieuwenhuis@DONDERS.RU.NL><br>
<b><span style='font-weight:bold'>To:</span></b> FIELDTRIP@NIC.SURFNET.NL<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, August 6, 2009
2:26:28 PM<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [FIELDTRIP]
freqanalysis_wltconvol variance</span></font><o:p></o:p></p>

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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dear Amr,</span></font><o:p></o:p></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font><o:p></o:p></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>If you do freqanalysis with cfg.keeptrials
= ‘yes’, you get the power per trial. If you subsequently use
freqdescriptives (see help for detailed options) you can compute the variance
over trials.</span></font><o:p></o:p></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font><o:p></o:p></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Best Ingrid</span></font><o:p></o:p></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font><o:p></o:p></p>

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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">FieldTrip discussion list</st1:PersonName>
[mailto:FIELDTRIP@NIC.SURFNET.NL] <b><span style='font-weight:bold'>On Behalf
Of </span></b>Amr Ayoub<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, August 06, 2009
1:56 PM<br>
<b><span style='font-weight:bold'>To:</span></b> FIELDTRIP@NIC.SURFNET.NL<br>
<b><span style='font-weight:bold'>Subject:</span></b> [FIELDTRIP]
freqanalysis_wltconvol variance</span></font><o:p></o:p></p>

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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>

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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hello,<br>
<br>
I am expecting that you are averaging the power spectrum across the trials in
freqanalysis_wltconvol. Is there a way to compute the variance across the
number of trials?<br>
<br>
Thanks in advance<br>
Amr Ayoub</span></font><o:p></o:p></p>

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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>

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<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>----------------------------------<o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>The aim
of this list is to facilitate the discussion between users of the FieldTrip
toolbox, to share experiences and to discuss new ideas for MEG and EEG
analysis.<o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><a
href="http://listserv.surfnet.nl/archives/fieldtrip.html" target="_blank">http://listserv.surfnet.nl/archives/fieldtrip.html</a><o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><a
href="http://www.ru.nl/fcdonders/fieldtrip/" target="_blank">http://www.ru.nl/fcdonders/fieldtrip/</a><o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>----------------------------------<o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>The aim
of this list is to facilitate the discussion between users of the FieldTrip
toolbox, to share experiences and to discuss new ideas for MEG and EEG
analysis.<o:p></o:p></span></font></p>

<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><a
href="http://listserv.surfnet.nl/archives/fieldtrip.html" target="_blank">http://listserv.surfnet.nl/archives/fieldtrip.html</a><o:p></o:p></span></font></p>

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<p>----------------------------------</p>
<p>The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis.</p>
<p>  http://listserv.surfnet.nl/archives/fieldtrip.html</p>
<p>  http://www.ru.nl/fcdonders/fieldtrip/</p>
<p>----------------------------------</p>
<p>The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis.</p>
<p>  http://listserv.surfnet.nl/archives/fieldtrip.html</p>
<p>  http://www.ru.nl/fcdonders/fieldtrip/</p>