<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi<div><br></div><div>I already have data which has been cleaned, filtered and artefact rejected etc. </div><div><br></div><div>It is now .mat format (trials X electrodes X time).</div><div><br></div><div>I can follow the advice from the wiki below to make a structure which should be compatible with ft_freqanalysis: </div><div><p><font class="Apple-style-span" face="'Comic Sans MS'">Alternatively, if you already are able to read the data into Matlab, you
can reformat that data within Matlab into a datastructure that is
compatible with FieldTrip. Raw data that is comparable with the output
of preprocessing should consist of a structure with the fields
</font></p>
<pre class="code"><font class="Apple-style-span" face="'Comic Sans MS'">data.label % cell-array containing strings, Nchan X 1
data.fsample % sampling frequency in Hz, single number
data.trial % cell-array containing a data matrix for each trial (1 X Ntrial), each data matrix is Nchan X Nsamples
data.time % cell-array containing a time axis for each trial (1 X Ntrial), each time axis is a 1 X Nsamples vector
data.trialinfo % this field is optional, but can be used to store trial-specific information, such as condition numbers, reaction times, correct responses etc. The dimensionality is N x M</font></pre></div><div><br></div><div>but when I try to run <font class="Apple-style-span" face="'Comic Sans MS'">ft_freqanalysis(cfg, data) </font>on this</div><div><br></div><div>I get the following error messages:</div><div><br></div><div><div><font class="Apple-style-span" face="'Comic Sans MS'">??? Error using ==> ft_checkdata at 366</font></div><div><font class="Apple-style-span" face="'Comic Sans MS'">This function requires raw, comp or mvar data as input.</font></div><div><font class="Apple-style-span" face="'Comic Sans MS'"><br></font></div><div><font class="Apple-style-span" face="'Comic Sans MS'">Error in ==> ft_freqanalysis at 219</font></div><div><font class="Apple-style-span" face="'Comic Sans MS'">data = ft_checkdata(data, 'datatype', {'raw', 'comp',</font></div><div><font class="Apple-style-span" face="'Comic Sans MS'">'mvar'}, 'feedback', cfg.feedback, 'hassampleinfo', 'yes');</font></div><div> </div></div><div>How to I tell the <font class="Apple-style-span" face="'Comic Sans MS'">ft_checkdata </font>function what datatype I have? Is this a simple problem?</div><div><br></div><div>Is it common to use fieldtrip functions on data which has already been preprocessed in another way? Or is this not advisable? </div><div><br></div><div>cheers,</div><div><br></div><div><br><div>
<div>Alexis</div><div><a href="mailto:alexis.makin@liv.ac.uk">alexis.makin@liv.ac.uk</a></div><div><br></div><div><span class="Apple-style-span" style="font-size: 13px; ">Network:</span><span class="Apple-style-span" style="font-size: 13px; "> </span><span class="Apple-style-span" style="font-size: 13px; "><a href="http://www.liv.ac.uk/perception-action/">www.liv.ac.uk/perception-action/</a></span></div><div><br></div><br class="Apple-interchange-newline">
</div>
<br></div></body></html>