function x = rectsig(N,fp,A,offset,duty)
%  rectsig --> Sum of square wave sequences.
%
%  <Synopsis>
%    x = rectsig(N,fp)
%    x = rectsig(N,fp,A)
%    x = rectsig(N,fp,A,offset)
%    x = rectsig(N,fp,A,offset,duty)
%
%  <Description>
%    Generates an N-vector, which is a sum of K square wave
%    sequences. The period frequencies are given by the K-vector
%    fp, where the elements -0.5 < fp(k) < 0.5 are the normalized
%    period frequencies, i.e., the 'analog' period frequency divided
%    by the sampling frequency. The K-vector A is the peak values,
%    and the K-vector offset is the percents in which the periods
%    are offset from zero. If any of the input arguments fp, A,
%    and offset is a scalar, then the value will be applied to all
%    the square wave sequences. The duty cycle, duty, is the
%    percent of the period in which the signal is positive.
%
%  <See Also>
%    sinsig --> Sum of sinusoidal sequences.
%    trisig --> Sum of sawtooth wave sequences.

%  <Revision>
%    Peter S.K. Hansen, IMM, Technical University of Denmark
%
%    Last revised: February 7, 2000
%-----------------------------------------------------------------------

% Check the required input arguments and set defaults.
if (nargin < 2)
  error('Not enough input arguments.')
end
if (nargin < 3)
  A = 1;
end
if (nargin < 4)
  offset = 0;
end
if (nargin < 5)
  duty = 50;
end

% Make sure that parameter vectors are column vectors.
fp = fp(:); A = A(:); offset = offset(:);

% Check the lenght of the input arguments.
Larg = [length(fp); length(A); length(offset)];
K    = max(Larg);

if any((Larg ~= 1) & (Larg < K))
  error('Vector valued input arguments must have same dimension.')
end

if (Larg(1) == 1)
  fp = fp*ones(K,1);
end
if (Larg(2) == 1)
  A = A*ones(K,1);
end
if (Larg(3) == 1)
  offset = offset*ones(K,1);
end

% Generate the sequence.
x = A'*square(2*pi*fp*(0:N-1) + 2*pi*offset/100*ones(1,N),duty);

%-----------------------------------------------------------------------
% End of function rectsig
%-----------------------------------------------------------------------