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b/featurebased-approach/PredictTestSet.m~ |
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function PredictTestSet(recordName,varargin) |
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% This function predicts the corresponding ECG class of a given record |
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% using our feature based approach. |
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% |
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% |
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% Input |
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% recordName: string specifying the record name to process |
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% (optional inputs) |
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% - useSegments: segment signals into windows (bool)? |
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% - windowSize: size of window used in segmenting record |
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% - percentageOverlap: overlap between windows |
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% -- |
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% ECG classification from single-lead segments using Deep Convolutional Neural |
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% Networks and Feature-Based Approaches - December 2017 |
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% |
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% Released under the GNU General Public License |
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% |
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% Copyright (C) 2017 Fernando Andreotti, Oliver Carr |
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% University of Oxford, Insitute of Biomedical Engineering, CIBIM Lab - Oxford 2017 |
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% fernando.andreotti@eng.ox.ac.uk |
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% |
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% |
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% For more information visit: https://github.com/fernandoandreotti/cinc-challenge2017 |
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% |
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% Referencing this work |
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% |
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% Andreotti, F., Carr, O., Pimentel, M.A.F., Mahdi, A., & De Vos, M. (2017). |
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% Comparing Feature Based Classifiers and Convolutional Neural Networks to Detect |
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% Arrhythmia from Short Segments of ECG. In Computing in Cardiology. Rennes (France). |
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% |
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% Last updated : December 2017 |
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% |
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% This program is free software: you can redistribute it and/or modify |
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% it under the terms of the GNU General Public License as published by |
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% the Free Software Foundation, either version 3 of the License, or |
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% (at your option) any later version. |
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% |
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% This program is distributed in the hope that it will be useful, |
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% but WITHOUT ANY WARRANTY; without even the implied warranty of |
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% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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% GNU General Public License for more details. |
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% |
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% You should have received a copy of the GNU General Public License |
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% along with this program. If not, see <http://www.gnu.org/licenses/>. |
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rng(1); % For reproducibility |
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%% Optional params |
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optargs = {1 10 0.8}; % default values for input arguments |
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newVals = cellfun(@(x) ~isempty(x), varargin); |
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optargs(newVals) = varargin(newVals); |
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[useSegments, windowSize, percentageOverlap] = optargs{:}; |
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clear optargs newVals |
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%% Loading signal |
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[~,signal,fs,~]=rdmat(recordName); |
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disp(['Processing ' recordName '...']) |
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if size(signal,1) < size(signal,2); signal = signal'; end % column vector |
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if any(isnan(signal)) |
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signal = inpaint_nans(signal); % function to remove NaNs |
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end |
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signalraw = signal; |
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% Parameters |
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NFEAT = 171; % number of features used |
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NFEAT_hrv = 113; |
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%% Initialize loop |
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% Wide BP |
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Fhigh = 5; % highpass frequency [Hz] |
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Flow = 45; % low pass frequency [Hz] |
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Nbut = 10; % order of Butterworth filter |
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d_bp= design(fdesign.bandpass('N,F3dB1,F3dB2',Nbut,Fhigh,Flow,fs),'butter'); |
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[b_bp,a_bp] = tf(d_bp); |
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% Narrow BP |
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Fhigh = 1; % highpass frequency [Hz] |
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Flow = 100; % low pass frequency [Hz] |
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Nbut = 10; % order of Butterworth filter |
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d_bp= design(fdesign.bandpass('N,F3dB1,F3dB2',Nbut,Fhigh,Flow,fs),'butter'); |
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[b_bp2,a_bp2] = tf(d_bp); |
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clear Fhigh Flow Nbut d_bp |
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%% Preprocessing |
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signal = filtfilt(b_bp,a_bp,signal); % filtering narrow |
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signal = detrend(signal); % detrending (optional) |
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signal = signal - mean(signal); |
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signal = signal/std(signal); % standardizing |
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signalraw = filtfilt(b_bp2,a_bp2,signalraw); % filtering wide |
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signalraw = detrend(signalraw); % detrending (optional) |
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signalraw = signalraw - mean(signalraw); |
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signalraw = signalraw/std(signalraw); % standardizing |
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disp(['Preprocessed ' recordName '...']) |
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% Figuring out if segmentation is used |
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if useSegments==1 |
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WINSIZE = windowSize; % window size (in sec) |
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OLAP = percentageOverlap; |
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else |
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WINSIZE = length(signal)/fs; |
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OLAP=0; |
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end |
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startp = 1; |
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endp = WINSIZE*fs; |
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looptrue = true; |
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nseg = 1; |
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while looptrue |
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% Conditions to stop loop |
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if length(signal) < WINSIZE*fs |
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endp = length(signal); |
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looptrue = false; |
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continue |
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end |
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if nseg > 1 |
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startp(nseg) = startp(nseg-1) + round((1-OLAP)*WINSIZE*fs); |
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if length(signal) - endp(nseg-1) < 0.5*WINSIZE*fs |
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endp(nseg) = length(signal); |
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else |
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endp(nseg) = startp(nseg) + WINSIZE*fs -1; |
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end |
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end |
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if endp(nseg) == length(signal) |
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looptrue = false; |
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nseg = nseg - 1; |
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end |
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nseg = nseg + 1; |
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end |
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%% Obtain features for each available segment |
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fetbag = {}; |
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parfor n = 1:nseg |
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% Get signal of interest |
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sig_seg = signal(startp(n):endp(n)); |
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sig_segraw = signalraw(startp(n):endp(n)); |
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% QRS detect |
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[qrsseg,featqrs] = multi_qrsdetect(sig_seg,fs,[recordName '_s' num2str(n)]); |
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% HRV features |
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if length(qrsseg{end})>5 % if too few detections, returns zeros |
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try |
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feat_basic=HRV_features(sig_seg,qrsseg{end}./fs,fs); |
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feats_poincare = get_poincare(qrsseg{end}./fs,fs); |
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feat_hrv = [feat_basic, feats_poincare]; |
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feat_hrv(~isreal(feat_hrv)|isnan(feat_hrv)|isinf(feat_hrv)) = 0; % removing not numbers |
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catch |
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warning('Some HRV code failed.') |
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feat_hrv = zeros(1,NFEAT_hrv); |
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end |
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else |
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disp('Skipping HRV analysis due to shortage of peaks..') |
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feat_hrv = zeros(1,NFEAT_hrv); |
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end |
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% Heart Rate features |
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HRbpm = median(60./(diff(qrsseg{end}))); |
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%obvious cases: tachycardia ( > 100 beats per minute (bpm) in adults) |
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feat_tachy = normcdf(HRbpm,120,20); % sampling from normal CDF |
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%See e.g. x = 10:10:200; p = normcdf(x,120,20); plot(x,p) |
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%obvious cases: bradycardia ( < 60 bpm in adults) |
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feat_brady = 1-normcdf(HRbpm,60,20); |
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% SQI metrics |
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feats_sqi = ecgsqi(sig_seg,qrsseg,fs); |
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% Features on residual |
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featsres = residualfeats(sig_segraw,fs,qrsseg{end}); |
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% Morphological features |
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feats_morph = morphofeatures(sig_segraw,fs,qrsseg,[recordName '_s' num2str(n)]); |
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feat_fer=[featqrs,feat_tachy,feat_brady,double(feats_sqi),featsres,feats_morph]; |
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feat_fer(~isreal(feat_fer)|isnan(feat_fer)|isinf(feat_fer)) = 0; % removing not numbers |
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% Save features to table for training |
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feats = [feat_hrv,feat_fer]; |
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fetbag{n} = feats; |
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end |
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feats = cell2mat(fetbag'); |
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% Standardizing input |
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feats = feats - nanmean(feats); |
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feats = feats./nanstd(feats); |
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feats(isnan(feats)) = 0; |
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NFEAT=size(feats,2); |
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delete('gqrsdet*.*') |
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clear fetbag b_bp b_bp2 endp looptrue signal signalraw startp useSegments windowSize |
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clear WINSIZE a_bp a_bp2 nseg OLAP percentageOverlap |
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%% Summarizing features |
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disp('Summarizing features ..') |
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featsum(1,1:NFEAT)=nanmean(feats); |
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featsum(1,1*NFEAT+1:2*NFEAT)=nanstd(feats); |
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if size(featsum,1)>2 |
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PCAn=pca(feats); |
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featsum(1,2*NFEAT+1:3*NFEAT)=PCAn(:,1); |
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featsum(1,3*NFEAT+1:4*NFEAT)=PCAn(:,2); |
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else |
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featsum(1,2*NFEAT+1:3*NFEAT)=NaN; |
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featsum(1,3*NFEAT+1:4*NFEAT)=NaN; |
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end |
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featsum(1,4*NFEAT+1:5*NFEAT)=nanmedian(feats); |
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featsum(1,5*NFEAT+1:6*NFEAT)=iqr(feats); |
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featsum(1,6*NFEAT+1:7*NFEAT)=range(feats); |
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featsum(1,7*NFEAT+1:8*NFEAT)=min(feats); |
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featsum(1,8*NFEAT+1:9*NFEAT)=max(feats); |
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featsum(1,9*NFEAT+1:10*NFEAT)=prctile(feats,25); |
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featsum(1,10*NFEAT+1:11*NFEAT)=prctile(feats,50); |
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featsum(1,11*NFEAT+1:12*NFEAT)=prctile(feats,75); |
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HIL=hilbert(feats); |
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featsum(1,12*NFEAT+1:13*NFEAT)=real(HIL(1,:)); |
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featsum(1,13*NFEAT+1:14*NFEAT)=abs(HIL(1,:)); |
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featsum(1,14*NFEAT+1:15*NFEAT)=skewness(feats); |
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featsum(1,15*NFEAT+1:16*NFEAT)=kurtosis(feats); |
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featsum(isnan(featsum)) = 0; |
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%% Using classifiers on feature table |
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% Loading classififers |
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slashchar = char('/'*isunix + '\'*(~isunix)); |
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mainpath = (strrep(which(mfilename),['preparation' slashchar mfilename '.m'],'')); |
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addpath(genpath([mainpath(1:end-length(mfilename)-2) 'classifiers' slashchar])) % add subfunctions folder to path |
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load('ensTree.mat') |
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load('nNets.mat') |
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% Performing classification |
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[~,probTree] = predict(ensTree_best,featsum); |
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probNN = nnet_best(featsum')'; |
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prob = mean([probTree;probNN]); |
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[~,class] = max(prob); |
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fprintf('Recording %s labels as %s with %d \% certainty ..',recordName,class,prob(class)) |
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