tfr_s.m

linear time－frequency toolbox

function f=tfr_s(self,c,Ls,dim)
%TFR_S  Synthesis transform
%  Usage: f=tfr_s(tfr,c)
%         f=tfr_s(tfr,c,Ls)
%         f=tfr_s(tfr,c,[],dim)
%         f=tfr_s(tfr,c,Ls,dim)
%
%   Input parameters:
%         tfr   : Time/frequency representation handle.
%         c     : Array of coefficients.
%         Ls    : length of signal.
%         dim   : Dimension of which to do the transform.
%   Output parameters:
%         f     : Signal.
%
%   TFR_S(tfr,c) computes the synthesis transform of the coefficients c as
%   speficied by tfr.
%
%   TFR_S(tfr,c,Ls) does as above but cuts or extends f to length Ls.
%
%   TFR_S(tfr,c,[],dim) applies the transform along dimension dim.
%   TFR_S(tfr,c,Ls,dim) does the same, but cuts or extends f to length Ls.
%
%   SEE ALSO:  TFR_CREATE, TFR_A, TFR_AR, TFR_CLEAR

error(nargchk(2,4,nargin));

D=ndims(c);

if nargin<4
  dim=1;
else
  if (prod(size(dim))~=1 || ~isnumeric(dim))
    error('dim must be a scalar.');
  end;
  if rem(dim,1)~=0
    error('dim must be an integer.');
  end;
  if (dim<1) || (dim>D)
    error(sprintf('dim must be in the range from 1 to %d.',D));
  end;
end;

if nargin<3
  Ls=-1;
else
  if isempty(Ls)
    Ls=-1;
  end;    
end;

if dim>1
  order=[dim, 1:dim-1,dim+1:D];

  % Put the desired dimension first.
  c=permute(c,order);

end;

% Remember the exact size for later.
permutedsize=size(c);
  
% Reshape c to a matrix.
c=reshape(c,size(c,1),prod(size(c))/size(c,1));


% Let comp_s do all the work.
f=comp_s(self,c,0,'TFR_S',Ls);

% Remember that we changed the length of the first dim.
permutedsize(1)=size(f,1);

% Restore the original, permuted shape, except for the first dimension
% which changed.
f=reshape(f,permutedsize);

if dim>1
  % Undo the permutation.
  f=ipermute(f,order);
end;