Plot actual values on 2-D disk

Francois · April 24, 2020, 9:24am

What kind of interpolation is used when plotting power with the 2D disc/cap?

The smoothing over the EEG cap is computed here:

brainstorm-tools/brainstorm3/blob/master/toolbox/gui/figure_topo.m#L716


      
              iPreStim = find(TimeVector < 0);

              if (length(iPreStim) > 50) && ~any(iPreStim > size(F,2))

                  FpreStim = F(:, iPreStim);

              else

                  FpreStim = F;

              end

              % This function does everything that is needed here

              WExtrap = channel_extrapm('GetTopoInterp', ChannelFile, selChan, Vertices, Faces, bfs_center, bfs_radius, FpreStim);

          % No magenetic extrap: Compute interpolation function from sensors to patch surface (simple 3D interp)

          else

              % Detect the points at (0,0,0)

              precision = 1e6;

              iChanZero = find(all(abs(chan_loc) < 1/precision, 2));

              % Check if some sensors are located at the same position

              GoodChanLoc = chan_loc;

              GoodChanLoc(iChanZero,:) = [];

              uniqueChanLoc = unique(round(GoodChanLoc * precision)/precision,'rows');

              % If number of unique positions is different from total number of channels, there are multiple sensors at the same place

              if (size(uniqueChanLoc,1) ~= size(GoodChanLoc, 1)) && ~isequal(TopoInfo.Modality, 'NIRS')

                  bst_error('Two or more sensors are located at the same position. Please try to fix this problem.', 'Plot topography', 0);

              end

Is there a way of making it less smooth?

Yes, with the menu "No smoothing":