1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166
|
function varargout=framemuleigs(Fa,Fs,s,varargin)
%-*- texinfo -*-
%@deftypefn {Function} framemuleigs
%@verbatim
%FRAMEMULEIGS Eigenpairs of frame multiplier
% Usage: [V,D]=framemuleigs(Fa,Fs,s,K);
% D=framemuleigs(Fa,Fs,s,K,...);
%
% Input parameters:
% Fa : Analysis frame
% Fs : Synthesis frame
% s : Symbol of Gabor multiplier
% K : Number of eigenvectors to compute.
% Output parameters:
% V : Matrix containing eigenvectors.
% D : Eigenvalues.
%
% [V,D]=FRAMEMULEIGS(Fa,Fs,s,K) computes the K largest eigenvalues
% and eigen-vectors of the frame multiplier with symbol s, analysis
% frame Fa and synthesis frame Fs. The eigenvectors are stored as
% column vectors in the matrix V and the corresponding eigenvalues in
% the vector D.
%
% If K is empty, then all eigenvalues/pairs will be returned.
%
% D=FRAMEMULEIGS(...) computes only the eigenvalues.
%
% FRAMEMULEIGS takes the following parameters at the end of the line of input
% arguments:
%
% 'tol',t Stop if relative residual error is less than the
% specified tolerance. Default is 1e-9
%
% 'maxit',n Do at most n iterations.
%
% 'iter' Call eigs to use an iterative algorithm.
%
% 'full' Call eig to solve the full problem.
%
% 'auto' Use the full method for small problems and the
% iterative method for larger problems. This is the
% default.
%
% 'crossover',c
% Set the problem size for which the 'auto' method
% switches. Default is 200.
%
% 'print' Display the progress.
%
% 'quiet' Don't print anything, this is the default.
%
% Examples:
% ---------
%
% The following example calculates and plots the first eigenvector of the
% Gabor multiplier given by the BATMASK function. Note that the mask
% must be converted to a column vector to work with in this framework:
%
% mask=batmask;
% [Fa,Fs]=framepair('dgt','gauss','dual',10,40);
% [V,D]=framemuleigs(Fa,Fs,mask(:));
% sgram(V(:,1),'dynrange',90);
%
%@end verbatim
%@strong{Url}: @url{http://ltfat.github.io/doc/operators/framemuleigs.html}
%@seealso{framemul, framemulappr}
%@end deftypefn
% Copyright (C) 2005-2016 Peter L. Soendergaard <peter@sonderport.dk>.
% This file is part of LTFAT version 2.3.1
%
% This program is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program. If not, see <http://www.gnu.org/licenses/>.
% Change this to 1 or 2 to see the iterative method in action.
printopts=0;
if nargin<2
error('%s: Too few input parameters.',upper(mfilename));
end;
if nargout==2
doV=1;
else
doV=0;
end;
tolchooser.double=1e-9;
tolchooser.single=1e-5;
definput.keyvals.K=6;
definput.keyvals.maxit=100;
definput.keyvals.tol=tolchooser.(class(s));
definput.keyvals.crossover=200;
definput.flags.print={'quiet','print'};
definput.flags.method={'auto','iter','full'};
[flags,kv,K]=ltfatarghelper({'K'},definput,varargin);
% Do the computation. For small problems a direct calculation is just as
% fast.
L=framelengthcoef(Fa,size(s,1));
if (flags.do_iter) || (flags.do_auto && L>kv.crossover)
if flags.do_print
opts.disp=1;
else
opts.disp=0;
end;
opts.isreal = Fa.realinput;
opts.maxit = kv.maxit;
opts.tol = kv.tol;
if doV
[V,D] = eigs(@(x) framemul(x,Fa,Fs,s),L,K,'LM',opts);
else
D = eigs(@(x) framemul(x,Fa,Fs,s),L,K,'LM',opts);
end;
else
% Compute the transform matrix.
bigM=frsynmatrix(Fs,L)*diag(s)*frsynmatrix(Fa,L)';
if doV
[V,D]=eig(bigM);
else
D=eig(bigM);
end;
end;
% The output from eig and eigs is sometimes a diagonal matrix, so we must
% extract the diagonal.
if doV
D=diag(D);
end;
% Sort them in descending order
[~,idx]=sort(abs(D),1,'descend');
D=D(idx(1:K));
if doV
V=V(:,idx(1:K));
varargout={V,D};
else
varargout={D};
end;
% Clean the eigenvalues, if we know that they are real-valued
%if isreal(ga) && isreal(gs) && isreal(c)
% D=real(D);
%end;
|