FT_DATABROWSER
Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_databrowser”.
FT_DATABROWSER can be used for visual inspection of data. Artifacts that were detected by artifact functions (see FT_ARTIFACT_xxx functions where xxx is the type of artifact) are marked. Additionally data pieces can be marked and unmarked as artifact by manual selection. The output cfg contains the updated specification of the artifacts. Use as cfg = ft_databrowser(cfg) cfg = ft_databrowser(cfg, data) If you only specify the configuration structure, it should contain the name of the dataset on your hard disk (see below). If you specify input data, it should be a data structure as obtained from FT_PREPROCESSING or from FT_COMPONENTANALYSIS. If you want to browse data that is on disk, you have to specify cfg.dataset = string with the filename Instead of specifying the dataset, you can also explicitely specify the name of the file containing the header information and the name of the file containing the data, using cfg.datafile = string with the filename cfg.headerfile = string with the filename The following configuration options are supported: cfg.ylim = vertical scaling, can be 'maxmin', 'maxabs' or [ymin ymax] (default = 'maxabs') cfg.zlim = color scaling to apply to component topographies, 'minmax', 'maxabs' (default = 'maxmin') cfg.blocksize = duration in seconds for cutting the data up cfg.trl = structure that defines the data segments of interest, only applicable for trial-based data cfg.continuous = 'yes' or 'no' whether the data should be interpreted as continuous or trial-based cfg.channel = cell-array with channel labels, see FT_CHANNELSELECTION cfg.channelclamped = cell-array with channel labels, that (when using the 'vertical' viewmode) will always be shown at the bottom. This is useful for showing ECG/EOG channels along with the other channels cfg.plotlabels = 'yes' (default), 'no', 'some'; whether to plot channel labels in vertical viewmode ('some' plots one in every ten labels; useful when plotting a large number of channels at a time) cfg.ploteventlabels = 'type=value', 'colorvalue' (default = 'type=value'); cfg.plotevents = 'no' or 'yes', whether to plot event markers. (default is 'yes') cfg.viewmode = string, 'butterfly', 'vertical', 'component' for visualizing ICA/PCA components (default is 'butterfly') cfg.artfctdef.xxx.artifact = Nx2 matrix with artifact segments see FT_ARTIFACT_xxx functions cfg.selectfeature = string, name of feature to be selected/added (default = 'visual') cfg.selectmode = 'markartifact', 'markpeakevent', 'marktroughevent' (default = 'markartifact') cfg.colorgroups = 'sequential' 'allblack' 'labelcharx' (x = xth character in label), 'chantype' or vector with length(data/hdr.label) defining groups (default = 'sequential') cfg.channelcolormap = COLORMAP (default = customized lines map with 15 colors) cfg.verticalpadding = number or 'auto', padding to be added to top and bottom of plot to avoid channels largely dissappearing when viewmode = 'vertical'/'component' (default = 'auto'). The padding is expressed as a proportion of the total height added to the top and bottom. The setting 'auto' determines the padding depending on the number of channels that are being plotted. cfg.selfun = string, name of function that is evaluated using the right-click context menu. The selected data and cfg.selcfg are passed on to this function. cfg.selcfg = configuration options for function in cfg.selfun cfg.seldat = 'selected' or 'all', specifies whether only the currently selected or all channels will be passed to the selfun (default = 'selected') cfg.renderer = string, 'opengl', 'zbuffer', 'painters', see MATLAB Figure Properties. If the databrowser crashes, you should try 'painters'. cfg.position = location and size of the figure, specified as a vector of the form [left bottom width height]. The following options for the scaling of the EEG, EOG, ECG, EMG and MEG channels is optional and can be used to bring the absolute numbers of the different channel types in the same range (e.g. fT and uV). The channel types are determined from the input data using FT_CHANNELSELECTION. cfg.eegscale = number, scaling to apply to the EEG channels prior to display cfg.eogscale = number, scaling to apply to the EOG channels prior to display cfg.ecgscale = number, scaling to apply to the ECG channels prior to display cfg.emgscale = number, scaling to apply to the EMG channels prior to display cfg.megscale = number, scaling to apply to the MEG channels prior to display cfg.gradscale = number, scaling to apply to the MEG gradiometer channels prior to display (in addition to the cfg.megscale factor) cfg.magscale = number, scaling to apply to the MEG magnetometer channels prior to display (in addition to the cfg.megscale factor) cfg.mychanscale = number, scaling to apply to the channels specified in cfg.mychan cfg.mychan = Nx1 cell-array with selection of channels cfg.chanscale = Nx1 vector with scaling factors, one per channel specified in cfg.channel cfg.compscale = string, 'global' or 'local', defines whether the colormap for the topographic scaling is applied per topography or on all visualized components (default 'global') You can specify preprocessing options that are to be applied to the data prior to display. Most options from FT_PREPROCESSING are supported. They should be specified in the sub-structure cfg.preproc like these examples cfg.preproc.lpfilter = 'no' or 'yes' lowpass filter (default = 'no') cfg.preproc.lpfreq = lowpass frequency in Hz cfg.preproc.demean = 'no' or 'yes', whether to apply baseline correction (default = 'no') cfg.preproc.detrend = 'no' or 'yes', remove linear trend from the data (done per trial) (default = 'no') cfg.preproc.baselinewindow = [begin end] in seconds, the default is the complete trial (default = 'all') In case of component viewmode, a layout is required. If no layout is specified, an attempt is made to construct one from the sensor definition that is present in the data or specified in the configuration. cfg.layout = filename of the layout, see FT_PREPARE_LAYOUT cfg.elec = structure with electrode positions, see FT_DATATYPE_SENS cfg.grad = structure with gradiometer definition, see FT_DATATYPE_SENS cfg.elecfile = name of file containing the electrode positions, see FT_READ_SENS cfg.gradfile = name of file containing the gradiometer definition, see FT_READ_SENS The default font size might be too small or too large, depending on the number of channels. You can use the following options to change the size of text inside the figure and along the axes. cfg.fontsize = number, fontsize inside the figure (default = 0.03) cfg.fontunits = string, can be 'normalized', 'points', 'pixels', 'inches' or 'centimeters' (default = 'normalized') cfg.axisfontsize = number, fontsize along the axes (default = 10) cfg.axisfontunits = string, can be 'normalized', 'points', 'pixels', 'inches' or 'centimeters' (default = 'points') cfg.linewidth = number, width of plotted lines (default = 0.5) When visually selection data, a right-click will bring up a context-menu containing functions to be executed on the selected data. You can use your own function using cfg.selfun and cfg.selcfg. You can use multiple functions by giving the names/cfgs as a cell-array. In butterfly and vertical mode, you can use the "identify" button to reveal the name of a channel. Please be aware that it searches only vertically. This means that it will return the channel with the amplitude closest to the point you have clicked at the specific time point. This might be counterintuitive at first. The "cfg.artfctdef" structure in the output cfg is comparable to the configuration used by the artifact detection functions like FT_ARTIFACT_ZVALUE and in FT_REJECTARTIFACT. It contains for each artifact type an Nx2 matrix in which the first column corresponds to the begin samples of an artifact period, the second column contains the end samples of the artifact periods. Note for debugging: in case the databrowser crashes, use delete(gcf) to kill the figure. See also FT_PREPROCESSING, FT_REJECTARTIFACT, FT_ARTIFACT_EOG, FT_ARTIFACT_MUSCLE, FT_ARTIFACT_JUMP, FT_ARTIFACT_MANUAL, FT_ARTIFACT_THRESHOLD, FT_ARTIFACT_CLIP, FT_ARTIFACT_ECG, FT_COMPONENTANALYSIS