Added overloaded vertcat method in dynSeries class.

*Exemple*

Suppose ts1, ts2, and ts3 are three dynSeries objects with the same variables. Then

ts4 = [ts1; ts2; ts3]

is a dynSeries object with the observations contained in ts1, ts2 and ts3 (in that order).

matlab/@dynSeries/vertcat.m

@@ -0,0 +1,143 @@
+function a = vertcat(varargin)
+
+%@info:
+%! @deftypefn {Function file} {@var{a} =} vertcat (@var{b},@var{c}, ...)
+%! @anchor{horzcat}
+%! @sp 1
+%! Method of the dynSeries class.
+%! @sp 1
+%! This method overloads the vertical concatenation operator, so that
+%! two (or more) time series objects containing the same variables 
+%! can be merged using the following syntax:
+%!
+%!     a = [b; c; d];
+%! @sp 2
+%! @strong{Inputs}
+%! @sp 1
+%! @table @ @var
+%! @item b
+%! Dynare time series object, instantiated by @ref{dynSeries}.
+%! @item c
+%! Dynare time series object, instantiated by @ref{dynSeries}.
+%! @end table
+%! @sp 2
+%! @strong{Outputs}
+%! @sp 1
+%! @table @var
+%! @item a
+%! Dynare time series object.
+%! @end table
+%! @end deftypefn
+%@eod:
+
+% Copyright (C) 2011-2013 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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.
+%
+% Dynare 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.
+
+    if nargin==0 
+        a = DynSeries();
+    elseif nargin == 1
+        a = varargin{1};
+    elseif nargin>1
+        a = varargin{1};
+        for i=2:nargin
+            a = vertcat_(a,varargin{i});
+        end
+    end
+
+end
+
+function d = vertcat_(b, c)
+    d = NaN;
+    if ~isequal(b.freq, c.freq)
+        error('dynSeries::vertcat: Frequencies must be common!')
+    end
+    if ~isequal(b.vobs, c.vobs)
+        error('dynSeries::vertcat: Number of variables must be common!')
+    end
+    if ~isequal(b.name, c.name)
+        error('dynSeries::vertcat: Variables must be common!')
+    end
+    d = b;
+    d.data = [b.data; c.data];
+    d.nobs = b.nobs+c.nobs;
+end
+
+%@test:1
+%$ % Define a data set.
+%$ A = [transpose(1:10),2*transpose(1:10)];
+%$ B = [transpose(1:10),2*transpose(1:10)];
+%$
+%$ % Define names
+%$ A_name = {'A1';'A2'};
+%$ B_name = {'A1';'A2'};
+%$
+%$ % Define expected results.
+%$ e.time = dynDate(1);
+%$ e.freq = 1;
+%$ e.name = {'A1';'A2'};
+%$ e.data = [A;B];
+%$
+%$ % Instantiate two time series objects.
+%$ ts1 = dynSeries(A,[],A_name,[]);
+%$ ts2 = dynSeries(B,[],B_name,[]);
+%$
+%$ % Call the tested method.
+%$ ts3 = [ts1;ts2];
+%$
+%$ % Check the results.
+%$
+%$ t(1) = dyn_assert(ts3.init,e.time);
+%$ t(2) = dyn_assert(ts3.freq,e.freq);
+%$ t(3) = dyn_assert(ts3.data,e.data);
+%$ t(4) = dyn_assert(ts3.name,e.name);
+%$ T = all(t);
+%@eof:1
+
+
+%@test:2
+%$ % Define a data set.
+%$ A = [transpose(1:10),2*transpose(1:10)];
+%$ B = [transpose(1:10),2*transpose(1:10)];
+%$ C = [transpose(1:10),3*transpose(1:10)];
+%$
+%$ % Define names
+%$ A_name = {'A1';'A2'};
+%$ B_name = {'A1';'A2'};
+%$ C_name = {'A1';'A2'};
+%$
+%$ % Define expected results.
+%$ e.time = dynDate(1);
+%$ e.freq = 1;
+%$ e.name = {'A1';'A2'};
+%$ e.data = [A;B;C];
+%$
+%$ % Instantiate two time series objects.
+%$ ts1 = dynSeries(A,[],A_name,[]);
+%$ ts2 = dynSeries(B,[],B_name,[]);
+%$ ts3 = dynSeries(C,[],C_name,[]);
+%$
+%$ % Call the tested method.
+%$ ts4 = [ts1;ts2;ts3];
+%$
+%$ % Check the results.
+%$
+%$ t(1) = dyn_assert(ts4.init,e.time);
+%$ t(2) = dyn_assert(ts4.freq,e.freq);
+%$ t(3) = dyn_assert(ts4.data,e.data);
+%$ t(4) = dyn_assert(ts4.name,e.name);
+%$ T = all(t);
+%@eof:2