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#### 65 lines 2.4 KiB Matlab Raw Permalink Blame History

 ```function [PksAndLocsCorrected] = StepcountFunc(dataAcc_filt,StrideTimeSamples,FS); ``` ``` ``` ```% Step count funciton extracted from other function called: ``` ``` ``` ```Cutoff = 0.1; ``` ```MinDist = floor(0.7*0.5*StrideTimeSamples); % Use StrideTimeSamples estimated above ``` ```DataLFilt = dataAcc_filt; ``` ``` ``` ```% From acceleration to ``` ```Vel = cumsum(detrend(DataLFilt,'constant'))/FS; ``` ```[B,A] = butter(2,Cutoff/(FS/2),'high'); ``` ```Pos = cumsum(filtfilt(B,A,Vel))/FS; ``` ```PosFilt = filtfilt(B,A,Pos); ``` ```PosFiltVT = PosFilt(:,1); ``` ``` ``` ```% Find minima and maxima in vertical position ``` ```[PosPks,PosLocs] = findpeaks(PosFiltVT(:,1),'minpeakdistance',MinDist); ``` ```[NegPks,NegLocs] = findpeaks(-PosFiltVT(:,1),'minpeakdistance',MinDist); ``` ```NegPks = -NegPks; ``` ```if isempty(PosPks) && isempty(NegPks) ``` ``` PksAndLocs = zeros(0,3); ``` ```else ``` ``` PksAndLocs = sortrows([PosPks,PosLocs,ones(size(PosPks)) ; NegPks,NegLocs,-ones(size(NegPks))], 2); ``` ```end ``` ```% Correct events for two consecutive maxima or two consecutive minima ``` ```Events = PksAndLocs(:,2); ``` ```NewEvents = PksAndLocs(:,2); ``` ```Signs = PksAndLocs(:,3); ``` ```FalseEventsIX = find(diff(Signs)==0); ``` ```PksAndLocsToAdd = zeros(0,3); ``` ```PksAndLocsToAddNr = 0; ``` ```for i=1:numel(FalseEventsIX), ``` ``` FIX = FalseEventsIX(i); ``` ``` if FIX <= 2 ``` ``` % remove the event ``` ``` NewEvents(FIX) = nan; ``` ``` elseif FIX >= numel(Events)-2 ``` ``` % remove the next event ``` ``` NewEvents(FIX+1) = nan; ``` ``` else ``` ``` StrideTimesWhenAdding = [Events(FIX+1)-Events(FIX-2),Events(FIX+3)-Events(FIX)]; ``` ``` StrideTimesWhenRemoving = Events(FIX+3)-Events(FIX-2); ``` ``` if max(abs(StrideTimesWhenAdding-StrideTimeSamples)) < abs(StrideTimesWhenRemoving-StrideTimeSamples) ``` ``` % add an event ``` ``` [M,IX] = min(Signs(FIX)*PosFiltVT((Events(FIX)+1):(Events(FIX+1)-1))); ``` ``` PksAndLocsToAddNr = PksAndLocsToAddNr+1; ``` ``` PksAndLocsToAdd(PksAndLocsToAddNr,:) = [M,Events(FIX)+IX,-Signs(FIX)]; ``` ``` else ``` ``` % remove an event ``` ``` if FIX >= 5 && FIX <= numel(Events)-5 ``` ``` ExpectedEvent = (Events(FIX-4)+Events(FIX+5))/2; ``` ``` else ``` ``` ExpectedEvent = (Events(FIX-2)+Events(FIX+3))/2; ``` ``` end ``` ``` if abs(Events(FIX)-ExpectedEvent) > abs(Events(FIX+1)-ExpectedEvent) ``` ``` NewEvents(FIX) = nan; ``` ``` else ``` ``` NewEvents(FIX+1) = nan; ``` ``` end ``` ``` end ``` ``` end ``` ```end ``` ```PksAndLocsCorrected = sortrows([PksAndLocs(~isnan(NewEvents),:);PksAndLocsToAdd],2); ``` ``` ``` `end`