vsblockc.m

Sparse Signal Representation using Overlapping Frames (matlab toolbox)

function W=VSblockC(X,F,S,VSalg,B,el,Bf)
% VSblockC  Vector Selection for block-oriented frame, (special version)
%           which use a compiled C++ program to do the actual work.
% The interface of this variant is much simpler than the VSblock function in FrameTools
% with fewer possibilities to specify how vector selection is to be done.
% If this function does not work as needed, or if it gives any errors,
% you should use VSblock in FrameTools or for overlapping frames the
% function VSolap1. 
%
% W=VSblockC(X,F,S,VSalg);       
% W=VSblockC(X,F,S,'VSps',M);       % algorithm may be gived as a string
%--------------------------------------------------------------------------------
% arguments:
%  W     - The weight matrix, W is a sparse matrix of size KxL
%  X     - The signal reshaped into blocks of length N, size NxL
%  F     - The frame of synthesis vectors (dictionary), size NxKx1  (P==1)
%          the vectors of F must be normalized, F(:,k)'*F(:,k)==1 for all k
%  S     - the third input argument is here DIFFERENT from in the FrameTools function
%          S is number of vectors to select for each coulmn vector in X
%  M     - number of combinations to search in VSps
%  VSalg - A number (or string) indicating which vector selection algorithm to use in VSblock.exe
%          1 - Basic Matching Pursuit
%          2 - Matching Pursuit (main loop is done more times)
%          3 - Matching Pursuit (main loop is done even more times)
%          4 - Orthogonal Matching Pursuit
%          5 - Order Recursive Matching Pursuit
%          6 - Partial Search 
%          7 - Always Better.  The previous weights must be written
%          to file filW before this function is called.
%--------------------------------------------------------------------------------

%--------------------------------------------------------------------------------
% Copyright (c) 2000.  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  15.05.2003  KS: VSblockC.m based on ..\FrameTools\VSblock
% Ver. 1.1  06.06.2003  KS: also VSps works!
% Ver. 1.2  11.06.2003  KS: added VSab
%--------------------------------------------------------------------------------

Mfile='VSblockC';
Display=0;        % decide if function display information
Pathst=which(Mfile);   % use catalog where this m-file is stored in, VSblockC.exe should also be here
i=find(Pathst=='\');i=i(length(i));
Pathst=Pathst(1:i);
% but these files should be in work directory
filF='filF.dat';    
filX='filX.dat';
filW='filW.dat';
filUt=[Mfile,'.log'];

if (nargin>5)
    disp('Perhaps you intended to use VSblock in FrameTools?'); 
    warning([Mfile,' should have 4 or 5 arguments, see help.']);
end
if (nargin==5)
    M=B;
else
    M=20;
end
if (nargin<4)
    error([Mfile,' should have 4 arguments, see help.']);
end
% disp(VSalg);
if isnumeric(VSalg) 
    Alg=floor(VSalg); 
    if ((Alg<0) | (Alg>7)); Alg=0; end;
else
    switch lower(VSalg)
        case {'vsmp','mp'}; Alg=1;
        case {'vsmp2','mp2'}; Alg=2;
        case {'vsmp3','mp3'}; Alg=3;
        case {'vsomp2','omp2','vsomp','omp'}; Alg=4;
        case {'vsfomp2','fomp2','vsfomp','fomp','vsormp','ormp'}; Alg=5;
        case {'vsps','ps'}; Alg=6;
        case {'vsab','ab'}; Alg=7;
        otherwise Alg=0;
    end
end
if (Alg==0)
    warning([Mfile,' unknown Vector Selection Algorithm, use Basic Matching Pursuit.']);
    Alg=1;
end

S=S(1);
[n,L]=size(X);
[N,K,P]=size(F);           
if P>1
   error([Mfile,': P>1, VSolap1 or VSolap2 should be used for overlapping frame.']);
end
if n~=N
   error([Mfile,': size of X and F do not correspond, see help.']);
end   

% write variables to files
fid = fopen(filF,'wb');
fwrite(fid,N,'int');    % 32 bit
fwrite(fid,K,'int');  
fwrite(fid,P,'int');  
fwrite(fid,F,'float');
fclose(fid);
fid = fopen(filX,'wb');
fwrite(fid,X,'float');
fclose(fid);
%
arguments=[' A',int2str(Alg),' S',int2str(S),' M',int2str(M),' F',filF,' X',filX,' W',filW];
if (Display == 0) arguments=[arguments,' >>',filUt]; end;
system([Pathst,Mfile,arguments]);   % do the work!
%
if exist(filW,'file')
    fid = fopen(filW,'rb');
    W=fread(fid,[K,L],'float');
    fclose(fid);
else
    W=zeros(K,L);
end
W=sparse(W);

return