rmeddis@38: function [pooledIPIdata,ctr] = poolIPI_across_channels(IPIhisttime,IPIhistweight)
rmeddis@38: 
rmeddis@38: %function that pools IPIdata across all channels in order to plot the data
rmeddis@38: %as in Secker-Walker JASA 1990 Fig. 6
rmeddis@38: 
rmeddis@38: %plots IPI-Histograms in a matrix display as in Secker-Walker JASA 1990
rmeddis@38: %Fig. 4
rmeddis@38: %
rmeddis@38: %   Tim Jürgens, February 2011
rmeddis@38: %
rmeddis@38: % input:  IPIhisttime:     matrix containing the interval times found in the
rmeddis@38: %                          analysis
rmeddis@38: %                          first dimension: frequency channel
rmeddis@38: %                          second dimension: time step (hop position)
rmeddis@38: %                          third dimension: interval dimension (max 3)
rmeddis@38: %         IPIhistweight:   matrix containing the interval weights found in the
rmeddis@38: %                          analysis, same dimensions as IPIhisttime
rmeddis@38: % output: pooledIPIdata:   matrix containing the pooled and weighted IPI
rmeddis@38: %                          histograms as a function of time (hop position)
rmeddis@38: %                          first dimension: time step (hop position)                           
rmeddis@38: %                          second dimension: IPI intervals
rmeddis@38: %         ctr:             center values of classes of IPI intervals
rmeddis@38: % ATTENTION: depending on the amplitude of the signals the value
rmeddis@38: % 'verticalshift' might have to be adjusted in order to see structures in
rmeddis@38: % the plot
rmeddis@38: 
rmeddis@38: verticalshift =   3000; %0.008;%vertical shift of single time series in z-coordinate units
rmeddis@38: ctr = [0:0.02:5].*1e-3; %classes (center-values) of 20 microsec width
rmeddis@38: 
rmeddis@38: %preallocation of variables
rmeddis@38: pooledIPIdata = zeros(size(IPIhisttime,2),length(ctr));
rmeddis@38: smoothed_pooledIPI = zeros(size(IPIhisttime,2),length(ctr)-5);
rmeddis@38: 
rmeddis@38: for iCounter = 1:size(IPIhisttime,2) %one for time spacing
rmeddis@38:     %cannot use matlabs hist function because weighting must be applied
rmeddis@38:    
rmeddis@38:     tmpIPIhisttime = squeeze(IPIhisttime(:,iCounter,:));
rmeddis@38:     tmpIPIhistweight = squeeze(IPIhistweight(:,iCounter,:));
rmeddis@38:     tmpIPIhisttime = tmpIPIhisttime(:);
rmeddis@38:     tmpIPIhistweight = tmpIPIhistweight(:);
rmeddis@38:     for jCounter = 1:length(tmpIPIhisttime)
rmeddis@38:         %look which class
rmeddis@38:         [tmp1,classindex] = min(abs(tmpIPIhisttime(jCounter)-ctr));
rmeddis@38:         pooledIPIdata(iCounter,classindex) = pooledIPIdata(iCounter,classindex)+tmpIPIhistweight(jCounter);
rmeddis@38:     end
rmeddis@38:     
rmeddis@38: end
rmeddis@38: 
rmeddis@38: %smooth data using a 5-point hamming window
rmeddis@38: hamm_window = hamming(5);
rmeddis@38: for iCounter = 1:size(pooledIPIdata,1)
rmeddis@38:     for jCounter = 3:length(ctr)-2 %start with 3 and end with 2 samples
rmeddis@38:         %less the length of ctr in order not to get in conflict with the length of
rmeddis@38:         %the hamm_window
rmeddis@38:         smoothed_pooledIPI(iCounter,jCounter-2) = ...
rmeddis@38:             pooledIPIdata(iCounter,(jCounter-2):(jCounter+2))*hamm_window./sum(hamm_window);
rmeddis@38:     end
rmeddis@38: end
rmeddis@38: smoothed_ctr = ctr(3:end-2);
rmeddis@38: 
rmeddis@38: 
rmeddis@38: figure;
rmeddis@38: 
rmeddis@38: Tickvector = [];
rmeddis@38: TickLabels = [];
rmeddis@38: for iCounter = 1:size(IPIhisttime,2)
rmeddis@38:     hold on;
rmeddis@38:     verticalposition = verticalshift*(iCounter-1);
rmeddis@38:     %multiply by 1000 to set abscissa to ms units
rmeddis@38:     plot(1000.*smoothed_ctr, ...
rmeddis@38:         smoothed_pooledIPI(iCounter,:)+verticalposition, ...
rmeddis@38:         'k','LineWidth',2);  
rmeddis@38:     if mod(iCounter,5) == 1 %set best frequency as a label every 10 channels
rmeddis@38:         Tickvector = [Tickvector verticalposition];
rmeddis@38:         TickLabels = [TickLabels; (iCounter-1)*3]; %time spacing is every 3ms
rmeddis@38:     end
rmeddis@38: end
rmeddis@38: set(gca,'yTick',Tickvector,'yTickLabel',num2str(TickLabels,'%4.0f'));
rmeddis@38: ylabel('Stimulus Time (ms)');
rmeddis@38: xlabel('Interval (ms)');
rmeddis@38: xlim([min(1000*ctr) max(1000*ctr)]);
rmeddis@38: ylim([-verticalshift verticalposition+3*verticalshift]);
rmeddis@38: box on;