rmeddis@38: function [mappediih,centerfreqs] = map_iih_onto_log(iih,numchannels,sfreq)
rmeddis@38: 
rmeddis@38: %function to map an IPIH from the interval axis onto the frequency axis
rmeddis@38: %with no overlap and mean firing rate.
rmeddis@38: %
rmeddis@38: % Tim Juergens, September 2011
rmeddis@38: %
rmeddis@38: % input: iih: IPIH with dimensions interval (1) and time step (2)
rmeddis@38: %             the first dimension translates to time using the actual
rmeddis@38: %             sampling frequency
rmeddis@38: %        numchannels: number of desired channels
rmeddis@38: %        sfreq: sampling frequency
rmeddis@38: % output: mappediih: IPIH with dimensions frequency channel (1) and time
rmeddis@38: %                    step (2)
rmeddis@38: %         centerfreqs: center frequencies of the channels of mappediih
rmeddis@38: 
rmeddis@38: ctr_intervals = [1/sfreq:1/sfreq:size(iih,1)/sfreq];
rmeddis@38: lowestBF=1/ctr_intervals(end);
rmeddis@38: highestBF=10000;
rmeddis@38: 
rmeddis@38: borderfreqs = logspace(log10(lowestBF),log10(highestBF),numchannels+1);
rmeddis@38: 
rmeddis@38: for iCounter = 1:numchannels
rmeddis@38:     centerfreqs(iCounter)=(borderfreqs(iCounter)+borderfreqs(iCounter+1))/2;
rmeddis@38: end
rmeddis@38: 
rmeddis@38: for iCounter = 1:length(borderfreqs) %find the indices that correspond to the borderfrequencies of the BF filters
rmeddis@38:     [tmp,channelbordersIPIindex(iCounter)]=min(abs(borderfreqs(iCounter)-1./ctr_intervals));
rmeddis@38: end
rmeddis@38: 
rmeddis@38: for iCounter = 1:length(centerfreqs)
rmeddis@38:     %mapping with one interval sample overlap
rmeddis@38:     mappediih(iCounter,:) = mean(iih(channelbordersIPIindex(end-iCounter+1):channelbordersIPIindex(end-iCounter),:));
rmeddis@38: end
rmeddis@38: 
rmeddis@38: 
rmeddis@38: 
rmeddis@38: % OPTIONAL PLOTTING
rmeddis@38:             figure
rmeddis@38:             YTickIdx = 1:floor(numel(centerfreqs)/6):numel(centerfreqs);
rmeddis@38:             YTickIdxRev = numel(centerfreqs)+1-YTickIdx;
rmeddis@38:             if ~isempty(gca)
rmeddis@38:                 axes(gca);  %#ok<MAXES>
rmeddis@38:                 imagesc(mappediih);         
rmeddis@38:                 set(gca, 'YTick', YTickIdx);                
rmeddis@38:                 set(gca, 'YTickLabel', num2str(   centerfreqs(YTickIdxRev)', '%0.0f' ));
rmeddis@38:                 ylabel('cf in Hz')                
rmeddis@38:             end