--- a/main/control/INDEX	Wed Sep 21 19:44:48 2011 +0000
+++ b/main/control/INDEX	Wed Sep 21 20:22:37 2011 +0000
@@ -10,6 +10,7 @@
   frd
   ss
   tf
+  zpk
 Model Data Access
   @lti/dssdata
   @lti/frdata

--- a/main/control/devel/zpk.m	Wed Sep 21 19:44:48 2011 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,102 +0,0 @@
-## Copyright (C) 2011   Lukas F. Reichlin
-##
-## This file is part of LTI Syncope.
-##
-## LTI Syncope 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.
-##
-## LTI Syncope 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 LTI Syncope.  If not, see <http://www.gnu.org/licenses/>.
-
-## -*- texinfo -*-
-## @deftypefn {Function File} {@var{s} =} zpk (@var{"s"})
-## @deftypefnx {Function File} {@var{z} =} zpk (@var{"z"}, @var{tsam})
-## @deftypefnx {Function File} {@var{sys} =} zpk (@var{sys})
-## @deftypefnx {Function File} {@var{sys} =} zpk (@var{k})
-## @deftypefnx {Function File} {@var{sys} =} zpk (@var{z}, @var{p}, @var{k}, @dots{})
-## @deftypefnx {Function File} {@var{sys} =} zpk @var{z}, @var{p}, @var{k}, @var{tsam}, @dots{})
-## @deftypefnx {Function File} {@var{sys} =} zpk (@var{z}, @var{p}, @var{k}, @var{tsam}, @dots{})
-## Create transfer function model from zero-pole-gain data.
-##
-## @strong{Inputs}
-## @table @var
-## @item sys
-## LTI model to be converted to transfer function.
-## @item num
-## Numerator or cell of numerators.  Each numerator must be a row vector
-## containing the coefficients of the polynomial in descending powers of
-## the transfer function variable.
-## @item den
-## Denominator or cell of denominators.  Each denominator must be a row vector
-## containing the coefficients of the polynomial in descending powers of
-## the transfer function variable.
-## @item tsam
-## Sampling time in seconds.  If @var{tsam} is not specified, a continuous-time
-## model is assumed.
-## @item @dots{}
-## Optional pairs of properties and values.
-## Type @command{set (tf)} for more information.
-## @end table
-##
-## @strong{Outputs}
-## @table @var
-## @item sys
-## Transfer function model.
-## @end table
-##
-## @strong{Example}
-## @example
-## @group
-## @end group
-## @end example
-##
-## @seealso{tf, ss, dss, frd}
-## @end deftypefn
-
-## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
-## Created: September 2011
-## Version: 0.1
-
-function sys = zpk (z = {}, p = {}, k = [], varargin)
-
-  switch (nargin)
-    case 0
-      sys = tf ();
-      return;
-
-    case 1
-      if (isa (z, "lti") || is_real_matrix (z) || ischar (z))
-        sys = tf (z);
-        return;
-      else
-        print_usage ();
-      endif
-
-    case 2
-      if (ischar (z) && issample (p, -1))
-        sys = tf (z, p);
-      else
-        print_usage ();
-      endif
-
-    otherwise
-      if (! iscell (z))
-        z = {z};
-      endif
-      if (! iscell (p))
-        p = {p};
-      endif
-      num = cellfun (@(zer, gain) real (gain * poly (zer)), z, num2cell (k), "uniformoutput", false);
-      den = cellfun (@(pol) real (poly (pol)), p, "uniformoutput", false);
-      sys = tf (num, den, varargin{:});
-    endswitch
-
-endfunction
-

--- a/main/control/doc/NEWS	Wed Sep 21 19:44:48 2011 +0000
+++ b/main/control/doc/NEWS	Wed Sep 21 20:22:37 2011 +0000
@@ -14,6 +14,11 @@
       realization of SLICOT TD04AD is a minimal one.  Therefore certain poles
       and zeros might be missing.
 
+** zpk, @lti/zpkdata
+   -- Included wrappers that create transfer function model from zero-pole-gain
+      data (zpk) and zero-pole-gain data from lti models (zpkdata).  They are
+      stop-gap measures for compatibility until ZPK models are implemented.
+
 
 ===============================================================================
 control-2.1.55   Release Date: 2011-09-07   Release Manager: Lukas Reichlin

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main/control/inst/zpk.m	Wed Sep 21 20:22:37 2011 +0000
@@ -0,0 +1,104 @@
+## Copyright (C) 2011   Lukas F. Reichlin
+##
+## This file is part of LTI Syncope.
+##
+## LTI Syncope 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.
+##
+## LTI Syncope 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 LTI Syncope.  If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{s} =} zpk (@var{"s"})
+## @deftypefnx {Function File} {@var{z} =} zpk (@var{"z"}, @var{tsam})
+## @deftypefnx {Function File} {@var{sys} =} zpk (@var{sys})
+## @deftypefnx {Function File} {@var{sys} =} zpk (@var{k})
+## @deftypefnx {Function File} {@var{sys} =} zpk (@var{z}, @var{p}, @var{k}, @dots{})
+## @deftypefnx {Function File} {@var{sys} =} zpk @var{z}, @var{p}, @var{k}, @var{tsam}, @dots{})
+## @deftypefnx {Function File} {@var{sys} =} zpk (@var{z}, @var{p}, @var{k}, @var{tsam}, @dots{})
+## Create transfer function model from zero-pole-gain data.
+## This is just a stop-gap compatibility wrapper since zpk
+## models are not yet implemented.
+##
+## @strong{Inputs}
+## @table @var
+## @item sys
+## LTI model to be converted to transfer function.
+## @item z
+## Cell of vectors containing the zeros for each channel.
+## z@{i,j@} contains the zeros from input j to output i.
+## In the SISO case, a single vector is accepted as well.
+## @item p
+## Cell of vectors containing the poles for each channel.
+## p@{i,j@} contains the poles from input j to output i.
+## In the SISO case, a single vector is accepted as well.
+## @item k
+## Matrix containing the gains for each channel.
+## k(i,j) contains the gain from input j to output i.
+## @item tsam
+## Sampling time in seconds.  If @var{tsam} is not specified,
+## a continuous-time model is assumed.
+## @item @dots{}
+## Optional pairs of properties and values.
+## Type @command{set (tf)} for more information.
+## @end table
+##
+## @strong{Outputs}
+## @table @var
+## @item sys
+## Transfer function model.
+## @end table
+##
+## @seealso{tf, ss, dss, frd}
+## @end deftypefn
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: September 2011
+## Version: 0.1
+
+function sys = zpk (z = {}, p = {}, k = [], varargin)
+
+  switch (nargin)
+    case 0
+      sys = tf ();
+      return;
+
+    case 1
+      if (isa (z, "lti") || is_real_matrix (z) || ischar (z))
+        sys = tf (z);
+        return;
+      else
+        print_usage ();
+      endif
+
+    case 2
+      if (ischar (z) && issample (p, -1))
+        sys = tf (z, p);
+      else
+        print_usage ();
+      endif
+
+    otherwise
+      if (! iscell (z))
+        z = {z};
+      endif
+      if (! iscell (p))
+        p = {p};
+      endif
+      if (! size_equal (z, p, k))
+        error ("zpk: arguments z, p and k must have equal dimensions");
+      endif
+      num = cellfun (@(zer, gain) real (gain * poly (zer)), z, num2cell (k), "uniformoutput", false);
+      den = cellfun (@(pol) real (poly (pol)), p, "uniformoutput", false);
+      sys = tf (num, den, varargin{:});
+  endswitch
+
+endfunction
+