<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=us-ascii">
<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;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
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-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;
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="EN-GB" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal">Dear Fieldtrippers,<o:p></o:p></p>
<p class="MsoNormal">when reading Neuralynx ncs data I run into the following problem:
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">%----------------------------------------------------------------------------------%<o:p></o:p></p>
<p class="MsoNormal"><i>cfg = []; cfg.dataset = [dataset_directory filesep electrode '.ncs'];<o:p></o:p></i></p>
<p class="MsoNormal"><i>data_nse = ft_preprocessing(cfg);<o:p></o:p></i></p>
<p class="MsoNormal"><i><o:p> </o:p></i></p>
<p class="MsoNormal">>> <span style="color:red">Index exceeds matrix dimensions.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:red"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:red">Error in ft_read_data (line 1013)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:red"> dat = ncs.dat(begsample:endsample);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:red"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:red">Error in ft_preprocessing (line 576)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:red"> dat = ft_read_data(cfg.datafile, 'header', hdr, 'begsample', begsample, 'endsample', endsample,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:red"> 'chanindx', rawindx, 'checkboundary', strcmp(cfg.continuous, 'no'), 'dataformat', cfg.dataformat);<o:p></o:p></span></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">The problem seems to be due to repeated timestamps in the data, that are corrected in @read_neuralynx_ncs line: 230
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[A,I] = unique(val); % consider only the unique values<o:p></o:p></p>
<p class="MsoNormal">indx = indx(I);<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This causes the information about the number of samples in the header and the actual samples to be different.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My question is now: How do I deal with this? Especially since I am not entirely sure why fieldtrip handles this dataformat the way it does (e.g. sorting the timestamps at each sampling point)
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So, can I just comment this out and accept the multiple sampling of some Timestamps? Or should I rather correct the information about the number of samples?
<o:p></o:p></p>
<p class="MsoNormal">Should I even interpolate plausible Timestamps?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any help is highly appreciated! <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">All the best,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sebastian<o:p></o:p></p>
</div>
</body>
</html>