setf07.m

Sparse Signal Representation using Overlapping Frames (matlab toolbox)

function ErrCode=SetF07(FrameFile)
% SetF07    Set F as a general filter bank with N=8, K=16, P=6 and Q=208
%           The FrameFile will be of Type 'g' 
% Some values here are chosen to fit the hump in an ecg signal.
%
% ErrCode=SetF07(FrameFile);
% -----------------------------------------------------------------------------------
% Arguments:
%  ErrCode   - 0 is returned if the function execute without error
%              1 an 'unexpected' error occurred, lasterr may explain it
%              2 or larger, another error occurred, 
%  FrameFile - the name of the mat-file used to store the frame
% -----------------------------------------------------------------------------------

%----------------------------------------------------------------------
% Copyright (c) 2001.  Karl Skretting.  All rights reserved.
% Hogskolen in Stavanger (Stavanger University), Signal Processing Group
% Mail:  [e-mail]   Homepage:  http://www.ux.his.no/~karlsk/
% 
% HISTORY:  dd.mm.yyyy
% Ver. 1.0  07.05.2001  KS: function made
% Ver. 1.1  04.12.2002  KS: moved from ..\Frames to ..\FrameTools
%----------------------------------------------------------------------

Mfile='SetF07';
ErrCode=0; 

if (nargin ~= 1)
   disp([Mfile,': wrong number of arguments, see help.']);
   ErrCode=2;
   return
end

try
   if exist([FrameFile,'.mat'])
      disp([Mfile,': ',FrameFile,'.mat already exists, it will be overwritten.']);
   end
catch
   ErrCode=3;
   return
end

% initialize the variable in FrameFile
Class='';
Type='g';
Mdim=1;
Dtab=[];Ctab=[];  
Savg=0;
Mdat=0;
PreProc=struct('Prog1','','Prog2','','Method',[],'arg1',[],'arg2',[],'arg3',[]);
VecSel=struct('Prog1','','arg1',[],'arg2',[],'arg3',[],'arg4',[],'arg5',[]);
InitialF=struct('Prog1',Mfile,'arg1',FrameFile,'arg2',[],'arg3',[],...
   'arg4',[],'arg5',[]);
History='';
SNRtot=[];

% set N, K and P
N=8;K=16;P=6;
F=[];
G=zeros(N*P,K);
% some other values  (part of normal ecg signal)
b=[ -11.9412  -12.1618  -12.3088  -12.2794  -13.0147  -13.3676  -14.6471
    -16.7941  -20.3971  -25.3088  -31.2353  -36.3235  -40.7647  -45.5882
    -49.5882  -47.5294  -35.0441  -13.0441   13.8382   45.0735   86.0882
    137.5294  187.0735  223.4118  239.1618  227.3235  179.5588  106.7647
    35.7206  -11.4265  -31.8824  -34.3382  -29.3382  -23.7794  -21.4412
    -20.6912  -19.8971  -18.8824  -18.3971  -18.4118  -18.8971  -19.0000
    -18.9412  -19.1324  -19.3971  -19.6765  -19.6765  -19.3824    0.0]';
b=b(:);b=b(1:48);b1=b;
w=hanning(16);
b(1:8)=b(1:8).*w(1:8);
b(41:48)=b(41:48).*w(9:16);
b=b/sqrt(b'*b); 
F=[F;b];
G(:,1)=(1:48)';
b=[b1(1)*0.96;b1(1)*0.97;b1(1)*0.98;b1(1)*0.99;b1(1:44)];
b(1:8)=b(1:8).*w(1:8);
b(41:48)=b(41:48).*w(9:16);
b=b/sqrt(b'*b); 
F=[F;b(1:4)];
G(:,2)=[(49:52)';(1:44)'];Q=52;
% the first 2 filter are designed, now make filters 3 and 4 (symmetric)
b=ones(48,1);
b(1:8)=b(1:8).*w(1:8);
b(41:48)=b(41:48).*w(9:16);
b=b/sqrt(b'*b); 
F=[F;b(1:24)];q=((Q+1):(Q+24))';Q=Q+24;
G(:,3)=[q;flipud(q)];
b=GetLOT(24);b=b(:,1);
b(1:8)=b(1:8).*w(1:8);
b(41:48)=b(41:48).*w(9:16);
b=b/sqrt(b'*b); 
F=[F;b(1:24)];q=((Q+1):(Q+24))';Q=Q+24;
G(:,4)=[q;flipud(q)];
% now make the next 6, LP and BP filters from 24x12 LOT
b1=GetLOT(12,0.95);
for k=1:6
   b=-b1(:,k);
   b=b/sqrt(b'*b); 
   F=[F;b(1:12)];q=((Q+1):(Q+12))';Q=Q+12;
   G(13:36,4+k)=[q;(1-2*mod(k+1,2))*flipud(q)];
end
% now make the last 6, BP filters from 12x12 DCT
b1=idct(eye(12));
b1=b1(:,5:10);
for k=1:6
   b=b1(:,k).*w(3:14);
   b=b/sqrt(b'*b); 
   F=[F;b(1:6)];q=((Q+1):(Q+6))';Q=Q+6;
   G(19:30,10+k)=[q;flipud(q).*(1-2*mod(k+1,2))];
end
% now F and G are made, reshape G from NPxK to NxKxP
temp=G;G=zeros(N,K,P);
for p=1:P; G(:,:,p)=temp((1:N)+(p-1)*N,:); end;

% find Ctab and Dtab and SizeF
[Ctab,Dtab]=MapCD(G);
SizeF=size(G);
Fbest=F;
History=char([Mfile,' ',datestr(now),', initialized the frame ',FrameFile],...
   ['using some ad-hoc defined FIR filters, giving N=',...
    int2str(N),' K=',int2str(K),' P=',int2str(P),' Q=',int2str(Q)]);
% save the frame in a file 
try
   save(FrameFile,'Class','Type','Mdim','F','SizeF','G','Ctab','Dtab',...
        'Fbest','Savg','Mdat','PreProc','VecSel','InitialF','History','SNRtot');
catch
   disp([Mfile,': error saving ',FrameFile,'.']);
   ErrCode=9;
   return
end

return


% testing
clear all
FrameFile='test';
ErrCode=SetF07(FrameFile);
load(FrameFile);
disp(['The value of Q is ',int2str(max(G(:))),'==',int2str(size(F,1))]);
PlotF(BuildFg(F,G),size(G));

      
% select some filters adapted to ECG signal
% this find the values for the b used in the function
clear all;
L=20000;
Limit=150;
[x,fs]=GetSignal(11,L);
I=[];
i1=0;i2=0;
for i=25:(L-25)
   if x(i)>Limit
      if (~i1); i1=i; end
      i2=0;
   else
      if (~i2); i2=i; end 
   end
   if i1 & i2
      I=[I,floor((i1+i2)/2)];
      i1=0;
   end
end
% I=floor(I/4)*4+1;
X=zeros(48,length(I));
for i=1:length(I)
   xi=I(i);
   X(:,i)=x((xi-24):(xi+23));
end
b=mean(X')';
Y=X-b*ones(1,length(I));  % the errors