p wave detection using discrete wavelet transform

I selected a window from qrs onset and performed dwt on it. But Pwave is not getting higlighted Algorithm is from paper "Adaptive ECG interval extraction"

% p wave for r=1:1 i=Qb(r); % from QRS onset k=i-31:i; L2=y(k); clc % Load original one-dimensional signal. s = L2; % Perform decomposition at level 3 of s using db1. numlevels = 3; [c,l] = wavedec(s,numlevels,'db1'); % Using some plotting commands, % the following figure is generated.

figure(1) numplots = length(l);

% Plot the original signal subplot(numplots,1,1) plot(s), axis tight title('Original Signal') grid on

% Plot the approximation signal subplot(numplots,1,2) plot(appcoef(c,l,'db1')), axis tight title('Approximation Coefficients') grid on

for i = 1:numlevels subplot(numplots,1,i+2) plot(detcoef(c,l,i)), axis tight title(['Detail Coefficients at Level ' num2str(i)]) grid on end

end