<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=DE link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Michael,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Many thanks for your informative reply. I was able to use the reverse normalization technique and eliminated the ft_sourceinterpolate and ft_volumenormalise commands.</span><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:EN-US'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> However, after I subtract ‘sourceA’ from ‘sourceB’ I now get the error “different grid locations in source reconstructions” when I try to do a ft_sourcegrandaverage. Any suggestions would be very welcome.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks in advance.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Jason<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> fieldtrip-bounces@donders.ru.nl [mailto:fieldtrip-bounces@donders.ru.nl] <b>On Behalf Of </b>Michael Wibral<br><b>Sent:</b> Mittwoch, 14. März 2012 20:29<br><b>To:</b> Email discussion list for the FieldTrip project<br><b>Subject:</b> Re: [FieldTrip] missing pos in beamforming<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>Dear Jason,<br><br>the pos indicates where the original sources were (i.e. on a regular grid with a certain spacing or self-defined). After interpolation this information does not reflect the data anymore. I would suggest to use Ingrid nieuwenhuis famous reverse normalization technique to create individual subject grids taht all match in MNI space - the script is found on the ft website. Sourceinterpoltae should really only be used for plotting IMHO.<br><br>Michael<o:p></o:p></p><div style='border:none;border-left:solid #C3D9E5 1.5pt;padding:0cm 0cm 0cm 8.0pt;margin-left:7.5pt;margin-top:7.5pt;margin-right:3.75pt;margin-bottom:3.75pt;word-wrap: break-word;-webkit-nbsp-mode: space;-webkit-line-break: after-white-space' name=quote><div style='margin-bottom:7.5pt'><p class=MsoNormal><b>Gesendet:</b> Mittwoch, 14. März 2012 um 17:28 Uhr<br><b>Von:</b> "Jason Chan" <<a href="mailto:chan@med.uni-frankfurt.de">chan@med.uni-frankfurt.de</a>><br><b>An:</b> <a href="mailto:fieldtrip@donders.ru.nl">fieldtrip@donders.ru.nl</a><br><b>Betreff:</b> [FieldTrip] missing pos in beamforming <o:p></o:p></p></div><div name=quoted-content><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Greetings,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I am adapting the beamformer tutorial to my data. When I <span style='font-size:10.0pt;font-family:"Courier New";color:black'>sourceinterpolate</span> the subtracted sourceA from sourceB data, the ‘pos’ disappears. This seems to be important for the volume normalization and Grand Average. I am running Fieldtrip version: 20110917. I have placed the code below.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Many thanks in advance.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Jason<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'>Young_CombineFilter_sourceDiff_16_3={};</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:blue'>for</span><span style='font-size:10.0pt;font-family:"Courier New";color:black'> i=1:length(Young_CombineFilter_beamform_16_3);</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg=[];</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> Young_CombineFilter_sourceDiff_16_3{i} =Young_CombineFilter_beamform_16_3{i}.sourceA;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> Young_CombineFilter_sourceDiff_16_3{i}.avg.pow =(Young_CombineFilter_beamform_16_3{i}.sourceA.avg.pow - Young_CombineFilter_beamform_16_3{i}.sourceB.avg.pow)./Young_CombineFilter_beamform_16_3{i}.sourceB.avg.pow;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg = [];</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg.downsample = 2;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg.parameter = </span><span style='font-size:10.0pt;font-family:"Courier New";color:#A020F0'>'avg.pow'</span><span style='font-size:10.0pt;font-family:"Courier New";color:black'>;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg.anatomy = mri{i};</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg.keepfilter=</span><span style='font-size:10.0pt;font-family:"Courier New";color:#A020F0'>'yes'</span><span style='font-size:10.0pt;font-family:"Courier New";color:black'>;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> cfg.interpmethod=</span><span style='font-size:10.0pt;font-family:"Courier New";color:#A020F0'>'linear'</span><span style='font-size:10.0pt;font-family:"Courier New";color:black'>;</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:black'> Young_CombineFilter_sourceDiffInt_16_3{i}=ft_sourceinterpolate(cfg,Young_CombineFilter_sourceDiff_16_3{i}, mri_young{i});</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Courier New";color:blue'>end</span><span style='font-size:10.0pt;font-family:"Courier New";color:black'>;</span><o:p></o:p></p></div></div></div></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>