<div dir="ltr">Dear all, I am relatively new to fieldtrip, so any help would be greatly appreciated! <div>I am trying to construct a source model using the following code from a MEG co-registered MRI. </div><div><br></div><div>------------------------------------------------------</div><div>%% starting from segmentation</div><div>





<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(2,128,9)">%% segment mri<span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg = [];</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.tissue = <span class="gmail-s1" style="color:rgb(170,4,249)">'brain'</span>;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.spmversion = <span class="gmail-s1" style="color:rgb(170,4,249)">'spm12'</span>;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">seg = ft_volumesegment(cfg, mri_realigned);</p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">save (<span class="gmail-s1" style="color:rgb(170,4,249)">'seg'</span>);<span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(2,128,9)">% cfg = [];</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.tissue = <span class="gmail-s1" style="color:rgb(170,4,249)">'brain'</span>;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.spmversion = <span class="gmail-s1" style="color:rgb(170,4,249)">'spm12'</span>;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">brain_mesh = ft_prepare_mesh(cfg, seg);</p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg = [];</p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(2,128,9)"><span class="gmail-s2" style="color:rgb(0,0,0)">cfg.method = </span><span class="gmail-s1" style="color:rgb(170,4,249)">'localspheres'</span><span class="gmail-s2" style="color:rgb(0,0,0)">; </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.grad = data.grad;<span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">headmodel = ft_prepare_headmodel(cfg, brain_mesh);</p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(170,4,249)"><span class="gmail-s2" style="color:rgb(0,0,0)">save (</span>'headmodel'<span class="gmail-s2" style="color:rgb(0,0,0)">)</span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">clear <span class="gmail-s1" style="color:rgb(170,4,249)">seg</span><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(2,128,9)">%% construction of source model<span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg = [];</p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(2,128,9)"><span class="gmail-s2" style="color:rgb(0,0,0)">cfg.resolution = 0.005; </span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.unit = <span class="gmail-s1" style="color:rgb(170,4,249)">'m'</span>;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.headmodel = headmodel;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">cfg.grad = data.grad;</p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier">sourcemodel = ft_prepare_sourcemodel(cfg);</p>
<p class="gmail-p3" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;min-height:12px"><span class="gmail-Apple-converted-space"> </span></p>
<p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(170,4,249)"><span class="gmail-s2" style="color:rgb(0,0,0)">save (</span>'sourcemodel'<span class="gmail-s2" style="color:rgb(0,0,0)">)<span class="gmail-Apple-converted-space"> </span></span></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(170,4,249)"><span class="gmail-s2" style="color:rgb(0,0,0)"><span class="gmail-Apple-converted-space"><br></span></span></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif">------------------------------------------------------</font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif"><br></font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif"><br></font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif">This code runs well up to the construction of the head model, but I get the following error while trying to make the source-model (a screenshot of the same is attached). When I run this code using 'singleshell' head model instead of 'localsheres' it works just fine. </font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif"><br></font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif"><br></font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" style="" face="arial, sans-serif">----------------------------------------------------------</font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal">Error using headsurface (line 155)<br>there should be just as many spheres as coils<br><br>Error in ft_prepare_sourcemodel (line 380)<br>        pos = headsurface(headmodel, sens);<font color="#000000" style="" face="arial, sans-serif"><br></font></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal">-----------------------------------------------------------</p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><br></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal">Could anyone suggest how to resolve this. Thanks a lot! </p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><br></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal">Kind regards </p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal">Kirandeep Kaur </p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><br></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><br></p><p class="gmail-p4" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:10px;line-height:normal;font-family:Courier;color:rgb(170,4,249)"><span class="gmail-s2" style="color:rgb(0,0,0)"><span class="gmail-Apple-converted-space"><br></span></span></p></div></div>