--- a/scripts/signal/unwrap.m	Tue Jan 22 21:34:24 2008 +0000
+++ b/scripts/signal/unwrap.m	Tue Jan 22 21:52:26 2008 +0000
@@ -93,3 +93,44 @@
   retval = a + r;
 
 endfunction
+
+%!function t = xassert(a,b,tol)
+%!  if (nargin == 1)
+%!    t = all(a(:));
+%!  else
+%!    if (nargin == 2)
+%!      tol = 0;
+%!    endif
+%!    if (any (size(a) != size(b)))
+%!      t = 0;
+%!    elseif (any (abs(a(:) - b(:)) > tol))
+%!      t = 0;
+%!    else
+%!      t = 1;
+%!    endif
+%!  endif
+%!
+%!test
+%! 
+%! i = 0;
+%! t = [];
+%! 
+%! r = [0:100];                        # original vector
+%! w = r - 2*pi*floor((r+pi)/(2*pi));  # wrapped into [-pi,pi]
+%! tol = 1e3*eps;                      # maximum expected deviation
+%! 
+%! t(++i) = xassert(r, unwrap(w), tol);               #unwrap single row
+%! t(++i) = xassert(r', unwrap(w'), tol);             #unwrap single column
+%! t(++i) = xassert([r',r'], unwrap([w',w']), tol);   #unwrap 2 columns
+%! t(++i) = xassert([r;r], unwrap([w;w],[],2), tol);  #verify that dim works
+%! t(++i) = xassert(r+10, unwrap(10+w), tol);         #verify that r(1)>pi works
+%! 
+%! t(++i) = xassert(w', unwrap(w',[],2));  #unwrap col by rows should not change it
+%! t(++i) = xassert(w, unwrap(w,[],1));    #unwrap row by cols should not change it
+%! t(++i) = xassert([w;w], unwrap([w;w])); #unwrap 2 rows by cols should not change them
+%! 
+%! ## verify that setting tolerance too low will cause bad results.
+%! t(++i) = xassert(any(abs(r - unwrap(w,0.8)) > 100));
+%! 
+%! assert(all(t));
+