Create RLW_weighted_channel_average_template_2308_edit

RLW/RLW_weighted_channel_average_template_2308_edit

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+function [template_weights,template_labels,message_string]=RLW_weighted_channel_average_template(header,data,varargin);
+%RLW_channel_average_template
+%
+%Channel average template
+%
+%varargin
+%'selected_channels' []
+%'num_channels' (6)
+%'x' (0)
+%'y' (0)
+%'z' (0)
+%'epoch' (1)
+%'index' (1)
+%'peakdir' ('max')
+%'normalize' (1)
+%
+%
+%
+% Author : 
+% Andre Mouraux
+% Institute of Neurosciences (IONS)
+% Universite catholique de louvain (UCL)
+% Belgium
+% 
+% Contact : andre.mouraux@uclouvain.be
+% This function is part of Letswave 6
+% See http://nocions.webnode.com/letswave for additional information
+%
+
+for i=1:length(header.chanlocs);
+    selected_channels{i}=header.chanlocs(i).labels;
+end;
+num_channels=6;
+x=0;
+y=0;
+z=0;
+epoch=1;
+index=1;
+peakdir='max';
+normalize=1;
+
+template_weights=[];
+template_labels=[];
+
+
+%parse varagin
+if isempty(varargin);
+else
+    %selected_channels
+    a=find(strcmpi(varargin,'selected_channels'));
+    if isempty(a);
+    else
+        selected_channels=varargin{a+1};
+    end;
+    %num_channels
+    a=find(strcmpi(varargin,'num_channels'));
+    if isempty(a);
+    else
+        num_channels=varargin{a+1};
+    end;
+    %x
+    a=find(strcmpi(varargin,'x'));
+    if isempty(a);
+    else
+        x=varargin{a+1};
+    end;
+    %y
+    a=find(strcmpi(varargin,'y'));
+    if isempty(a);
+    else
+        y=varargin{a+1};
+    end;
+    %z
+    a=find(strcmpi(varargin,'z'));
+    if isempty(a);
+    else
+        z=varargin{a+1};
+    end;
+    %epoch
+    a=find(strcmpi(varargin,'epoch'));
+    if isempty(a);
+    else
+        epoch=varargin{a+1};
+    end;
+    %index
+    a=find(strcmpi(varargin,'index'));
+    if isempty(a);
+    else
+        index=varargin{a+1};
+    end;
+    %peakdir
+    a=find(strcmpi(varargin,'peakdir'));
+    if isempty(a);
+    else
+        peakdir=varargin{a+1};
+    end;
+    %normalize
+    a=find(strcmpi(varargin,'normalize'));
+    if isempty(a);
+    else
+        normalize=varargin{a+1};
+    end;
+end;
+
+
+%init message_string
+message_string={};
+message_string{1}='Create weighted channel average template';
+
+message_string{end+1}=['Number of channels to include : ' num2str(num_channels)];
+
+%adjust epoch_pos, index_pos
+if header.datasize(1)==1;
+    epoch=1;
+end;
+if header.datasize(3)==1;
+    index=1;
+end;
+
+%chan_idx
+st={};
+for i=1:length(header.chanlocs);
+    st{i}=header.chanlocs(i).labels;
+end;
+chan_idx=[];
+for i=1:length(selected_channels);
+    a=find(strcmpi(selected_channels{i},st));
+    chan_idx=[chan_idx a];
+end;
+message_string{end+1}=[num2str(length(chan_idx)) ' channels with matching labels.'];
+
+%fetch vector
+dx=round(((x-header.xstart)/header.xstep))+1;
+if header.datasize(4)==1;
+    dz=1;
+else
+    dz=round(((z-header.zstart)/header.zstep))+1;
+end;
+if header.datasize(5)==1;
+    dy=1;
+else
+    dy=round(((y-header.ystart)/header.ystep))+1;
+end;
+chan_vector=squeeze(data(epoch,chan_idx,index,dz,dy,dx));
+
+%edit 23/08
+was_averaged=0;
+if length(dx)>1
+    chan_vector=mean(chan_vector,2);
+    was_averaged=1;
+end;
+
+if length(dy)>1
+    chan_vector=mean(chan_vector,2);
+    was_averaged=1;
+end;
+
+if length(dz)>1
+    chan_vector=mean(chan_vector,2);
+    was_averaged=1;
+end;
+
+%end edit
+
+
+%sort
+switch peakdir
+    case 'max'
+        [Y,I]=sort(chan_vector,'descend');
+        chan_idx=chan_idx(I(1:num_channels));
+        chan_weights=Y(1:num_channels);
+    case 'min'
+        [Y,I]=sort(chan_vector,'ascend');
+        chan_idx=chan_idx(I(1:num_channels));
+        chan_weights=Y(1:num_channels);
+    case 'absmax'
+        chan_vector=abs(chan_vector);
+        [Y,I]=sort(chan_vector,'descend');
+        chan_idx=chan_idx(I(1:num_channels));
+        chan_weights=Y(1:num_channels);
+end;
+
+%normalize
+if normalize==1;
+    chan_weights=chan_weights/sum(chan_weights);
+end;
+
+%edit 23/08
+if was_averaged==1
+    chan_weights=chan_weights';
+end;
+
+template_weights=chan_weights;
+template_labels=st(chan_idx);