%                                                          xcell = cellK(x,K)
% CELLK  Stores SeDuMi cone K-vector in cell-array format.
%
% On output xcell.f and xcell.l are the free and >=0 components,
% xcell.q{k}, xcell.r{k} and xcell.s{k} contain the Lorentz, 
% Rotated Lorentz, and PSD-components, resp.
% xcell.s{k} is a K.s(k) x K.s(k) matrix.
%
% SEE ALSO eigK, eyeK, sedumi.
function xcell = cellK(x,K)
 %  
 %   This file is part of SeDuMi 1.05
 %   Copyright (C) 2001 Jos F. Sturm
 %     Dept. Econometrics & O.R., Tilburg University, the Netherlands.
 %     Supported by the Netherlands Organization for Scientific Research (NWO).
 %   Affiliation SeDuMi 1.03 and 1.04Beta (2000):
 %     Dept. Quantitative Economics, Maastricht University, the Netherlands.
 %   Affiliations up to SeDuMi 1.02 (AUG1998):
 %     CRL, McMaster University, Canada.
 %     Supported by the Netherlands Organization for Scientific Research (NWO).
 % 
 %   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 2 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, write to the Free Software
 %   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 %

% Remark: the cell-array scheme is inspired by SDPT3.
% Unlike in SDPT3 though, the cells are grouped in
% fields like xcell.q and xcell.s.
 if nargin < 2
   error('cellK needs 2 input arguments')
 end
 if ~isstruct(K)
   error('K should be a structure')
 end
 i = 1;
 if isfield(K,'f')
   xcell.f = x(i:i+K.f-1);
   i = i + K.f;
 end
 if isfield(K,'l')
   xcell.l = x(i:i+K.l-1);
   i = i + K.l;
 end
 % ------------------------------------------------------------
 % Lorentz: this only works OUTSIDE sedumi, not for internal storage
 % ------------------------------------------------------------
 if isfield(K,'q')
   for k = 1: length(K.q)
     xcell.q{k} = x(i:i+K.q(k)-1);
     i = i + K.q(k);
   end
 end
 if isfield(K,'r')
   for k = 1: length(K.r)
     xcell.r{k} = x(i:i+K.r(k)-1);
     i = i + K.r(k);
   end
 end
 % ------------------------------------------------------------
 % PSD-blocks:
 % ------------------------------------------------------------
 if isfield(K,'s')
   if ~isfield(K,'rsdpN')
     for k = 1: length(K.s)
       xcell.s{k} = mat(x(i:i+K.s(k)^2-1));
       i = i + K.s(k)^2;
     end
   else
 % ------------------------------------------------------------
 % Only applicable for internal storage: complex-as-real-storage
 % ------------------------------------------------------------
     for k = 1: K.rsdpN
       xcell.s{k} = mat(x(i:i+K.s(k)^2-1));
       i = i + K.s(k)^2;
     end
     j = sqrt(-1);
     for k = K.rsdpN+1:length(K.s)
       xcell.s{k} = mat(x(i:i+K.s(k)^2-1));
       i = i + K.s(k)^2;
       xcell.s{k} = xcell.s{k} + j * mat(x(i:i+K.s(k)^2-1));
       i = i + K.s(k)^2;
     end
   end
 end


