--- /dev/null
+## Copyright (C) 2003 David Bateman
+##
+## 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/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} eyediagram (@var{x},@var{n})
+## @deftypefnx {Function File} {} eyediagram (@var{x},@var{n},@var{per})
+## @deftypefnx {Function File} {} eyediagram (@var{x},@var{n},@var{per},@var{off})
+## @deftypefnx {Function File} {} eyediagram (@var{x},@var{n},@var{per},@var{off},@var{str})
+## @deftypefnx {Function File} {} eyediagram (@var{x},@var{n},@var{per},@var{off},@var{str},@var{h})
+## @deftypefnx {Function File} {@var{h} =} eyediagram (@var{...})
+##
+## Plot the eye-diagram of a signal. The signal @var{x} can be either in one
+## of three forms
+##
+## @table @asis
+## @item A real vector
+## In this case the signal is assumed to be real and represented by the vector
+## @var{x}. A single eye-diagram representing this signal is plotted.
+## @item A complex vector
+## In this case the in-phase and quadrature components of the signal are
+## plotted seperately.
+## @item A matrix with two columns
+## In this case the first column represents the in-phase and the second the
+## quadrature components of a complex signal.
+## @end table
+##
+## Each line of the eye-diagram has @var{n} elements and the period is assumed
+## to be given by @var{per}. The time axis is then [-@var{per}/2 @var{per}/2].
+## By default @var{per} is 1.
+##
+## By default the signal is assumed to start at -@var{per}/2. This can be
+## overridden by the @var{off} variable, which gives the number of samples
+## to delay the signal.
+##
+## The string @var{str} is a plot style string (example 'r+'),
+## and by default is the default gnuplot line style.
+##
+## The figure handle to use can be defined by @var{h}. If @var{h} is not
+## given, then the next available figure handle is used. The figure handle
+## used in returned on @var{hout}.
+## @end deftypefn
+## @seealso{scatterplot}
+
+## 2005-04-23 Dmitri A. Sergatskov <dasergatskov@gmail.com>
+## * modified for new gnuplot interface (octave > 2.9.0)
+
+function varargout = eyediagram (x, n, _per, _off, str, h)
+
+ if ((nargin < 2) || (nargin > 6))
+ usage (" h = eyediagram (x, n [, per [, off [, str [, h]]]])");
+ endif
+
+ if (isreal(x))
+ if (min(size(x)) == 1)
+ signal = "real";
+ xr = x(:);
+ elseif (size(x,2) == 2)
+ signal = "complex";
+ xr = x(:,1);
+ xr = x(:,2);
+ else
+ error ("eyediagram: real signal input must be a vector");
+ endif
+ else
+ signal = "complex";
+ if (min(size(x)) != 1)
+ error ("eyediagram: complex signal input must be a vector");
+ endif
+ xr = real(x(:));
+ xi = imag(x(:));
+ endif
+
+ if (!length(xr))
+ error ("eyediagram: zero length signal");
+ endif
+
+ if (!isscalar(n) || !isreal(n) || (floor(n) != n) || (n < 1))
+ error ("eyediagram: n must be a positive non-zero integer");
+ endif
+
+ if (nargin > 2)
+ if (isempty(_per))
+ per = 1;
+ elseif (isscalar(_per) && isreal(_per))
+ per = _per;
+ else
+ error ("eyediagram: period must be a real scalar");
+ endif
+ else
+ per = 1;
+ endif
+
+ if (nargin > 3)
+ if (isempty(_off))
+ off = 0;
+ elseif (!isscalar(_off) || !isreal(_off) || (floor(_off) != _off) || ...
+ (_off < 0) || (_off > (n-1)))
+ error ("eyediagram: offset must be an integer between 0 and n");
+ else
+ off = _off;
+ endif
+ else
+ off = 0;
+ endif
+
+ if (nargin > 4)
+ if (isempty(str))
+ fmt = "-r";
+ elseif (ischar(str))
+ fmt = str;
+ else
+ error ("eyediagram: plot format must be a string");
+ endif
+ else
+ fmt = "-r";
+ endif
+
+ if (nargin > 5)
+ if (isempty(h))
+ hout = figure ();
+ else
+ hout = figure (h);
+ endif
+ else
+ hout = figure ();
+ endif
+
+ horiz = (per*[0:n]/n - per/2)';
+ if (2*floor(n/2) != n)
+ horiz = horiz - per / n / 2;
+ endif
+ lx = length(xr);
+ off = mod(off+ceil(n/2),n);
+ Nn = ceil((off + lx) / n);
+ post = Nn*n - off - lx;
+ xr = reshape([NaN * ones(off,1); xr; NaN * ones(post,1)],n,Nn);
+ xr = [xr ; [xr(1,2:end), NaN]];
+ xr = [xr; NaN*ones(1,Nn)];
+ if (all(isnan(xr(2:end,end))))
+ xr(:,end) = [];
+ horiz = [repmat(horiz(1:n+1),1,Nn-1);NaN*ones(1,Nn-1)](:);
+ else
+ horiz = [repmat(horiz(1:n+1),1,Nn);NaN*ones(1,Nn)](:);
+ endif
+
+ if (strcmp(signal,"complex"))
+ xi = reshape([NaN * ones(off,1); xi; NaN * ones(post,1)],n,Nn);
+ xi = [xi ; [xi(1,2:end), NaN]];
+ xi = [xi; NaN*ones(1,Nn)];
+ if (all(isnan(xi(2:end,end))))
+ xi(:,end) = [];
+ endif
+ endif
+
+ if (strcmp(signal,"complex"))
+ subplot(2,1,1);
+ plot(horiz,xr(:),fmt);
+ title("Eye-diagram for in-phase signal");
+ xlabel("Time");
+ ylabel("Amplitude");
+ subplot(2,1,2);
+ plot(horiz,xi(:),fmt);
+ title("Eye-diagram for quadrature signal");
+ xlabel("Time");
+ ylabel("Amplitude");
+ else
+ plot(horiz,xr(:),fmt);
+ title("Eye-diagram for signal");
+ xlabel("Time");
+ ylabel("Amplitude");
+ endif
+
+ if (nargout > 0)
+ varargout{1} = hout;
+ endif
+
+endfunction
+
+%!demo
+%! n = 50;
+%! ovsp=50;
+%! x = 1:n;
+%! xi = [1:1/ovsp:n-0.1];
+%! y = randsrc(1,n,[1 + 1i, 1 - 1i, -1 - 1i, -1 + 1i]) ;
+%! yi = interp1(x,y,xi);
+%! noisy = awgn(yi,15,"measured");
+%! eyediagram(noisy,ovsp);
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff