Added the possibility to select variables in a dynSeries object. It is...

Added the possibility to select variables in a dynSeries object. It is possible to use regular expressions.  Examples are given in unitary test #6 of subsref overloaded method.

matlab/@dynSeries/extract.m

+function A = extract(B,varargin)
+% Extract some variables from a database.
+
+A = dynSeries();
+
+% Get the names of the variables to be extracted from dynSeries object B.
+VariableName_ = {};
+for i=1:nargin-1
+    VariableName = varargin{i};
+    idArobase = strfind(VariableName,'@');
+    if length(idArobase)==2
+        first_block_id = 0;
+        last_block_id = 0;
+        if idArobase(1)>1
+            first_block_id = idArobase(1)-1;
+        end
+        if idArobase(2)<length(VariableName)
+            last_block_id = length(VariableName)-idArobase(2)-1;
+        end
+        VariableName(idArobase(1)) = '[';
+        VariableName(idArobase(2)) = ']';
+        idVariables = find(isnotempty_cell(regexp(B.name,VariableName,'match')));
+        if isempty(idVariables)
+            error(['dynSeries::extract: Can''t find any variable matching ' VariableName ' pattern!'])
+        end
+        idVariables_ = [];
+        for j = 1:length(idVariables)
+            first_block_flag = 0;
+            if (first_block_id && strcmp(B.name{idVariables(j)}(1:first_block_id),VariableName(1:first_block_id))) || ~first_block_id
+                first_block_flag = 1;
+            end
+            last_block_flag = 0;
+            if (last_block_id && strcmp(B.name{idVariables(j)}(end-last_block_id:end),VariableName(end-last_block_id:end))) || ~last_block_id
+                last_block_flag = 1;
+            end
+            if first_block_flag && last_block_flag
+                idVariables_ = [idVariables_; idVariables(j)];
+            end
+        end
+        VariableName = B.name(idVariables_);
+    end
+    VariableName_ = vertcat(VariableName_,VariableName);
+end
+
+% Get indices of the selected variables
+idVariableName = NaN(length(VariableName_),1);
+for i = 1:length(idVariableName)
+    idx = strmatch(VariableName_{i},B.name,'exact');
+    if isempty(idx)
+        error(['dynSeries::extract: Variable ' VariableName_{i} ' is not a member of ' inputname(1) '!'])
+    end
+    idVariableName(i) = idx;  
+end
+
+A.data = B.data(:,idVariableName);
+A.init = B.init;
+A.freq = B.freq;
+A.nobs = B.nobs;
+A.vobs = length(idVariableName);
+A.name = B.name(idVariableName);
+
+
+
+
+function b = isnotempty_cell(CellArray)
+    CellArrayDimension = size(CellArray);
+    b = NaN(CellArrayDimension);
+    for i=1:CellArrayDimension(1)
+        for j = 1:CellArrayDimension(2)
+            b(i,j) = ~isempty(CellArray{i,j});
+        end
+    end
\ No newline at end of file

matlab/@dynSeries/numel.m

+function n = numel(obj, varargin)
+    n = 1;
\ No newline at end of file

matlab/@dynSeries/subsref.m

@@ -114,8 +114,14 @@ if (length(S)==2) && (isequal(S(1).subs,'init'))
     else
         error('dynSeries:subsref:: I don''t understand what you are trying to do!')
     end
+    return
+end
+
+if (length(S)==1) && isequal(S(1).type,'{}')
+    us = extract(ts,S(1).subs{:});
 end
 
+
 %@test:1
 %$ % Define a data set.
 %$ A = [transpose(1:10),2*transpose(1:10)];
@@ -228,3 +234,75 @@ end
 %$ end
 %$ T = all(t);
 %@eof:4
+
+%@test:5
+%$ % Define a data set.
+%$ A = [transpose(1:10),2*transpose(1:10),3*transpose(1:10)];
+%$
+%$ % Define names
+%$ A_name = {'A1';'A2';'B1'};
+%$
+%$ % Instantiate a time series object.
+%$ ts1 = dynSeries(A,[],A_name,[]);
+%$
+%$ % Call the tested method.
+%$ a = ts1{'A1','B1'};
+%$
+%$ % Expected results.
+%$ e.data = A(:,[1,3]);
+%$ e.nobs = 10;
+%$ e.vobs = 2;
+%$ e.name = {'A1';'B1'};
+%$ e.freq = 1;
+%$ e.init = dynDate(1);
+%$
+%$ t(1) = dyn_assert(e.data,a.data);
+%$ t(2) = dyn_assert(e.nobs,a.nobs);
+%$ t(3) = dyn_assert(e.vobs,a.vobs);
+%$ t(4) = dyn_assert(e.name,a.name);
+%$ t(5) = dyn_assert(e.init,a.init);
+%$ T = all(t);
+%@eof:5
+
+%@test:6
+%$ % Define a data set.
+%$ A = rand(10,24);
+%$
+%$ % Define names
+%$ A_name = {'GDP_1';'GDP_2';'GDP_3'; 'GDP_4'; 'GDP_5'; 'GDP_6'; 'GDP_7'; 'GDP_8'; 'GDP_9'; 'GDP_10'; 'GDP_11'; 'GDP_12'; 'HICP_1';'HICP_2';'HICP_3'; 'HICP_4'; 'HICP_5'; 'HICP_6'; 'HICP_7'; 'HICP_8'; 'HICP_9'; 'HICP_10'; 'HICP_11'; 'HICP_12';};
+%$
+%$ % Instantiate a time series object.
+%$ ts1 = dynSeries(A,[],A_name,[]);
+%$
+%$ % Call the tested method.
+%$ a = ts1{'GDP_@0-9@'};
+%$ b = ts1{'@A-Z@_1'};
+%$
+%$ % Expected results.
+%$ e1.data = A(:,1:12);
+%$ e1.nobs = 10;
+%$ e1.vobs = 12;
+%$ e1.name = {'GDP_1';'GDP_2';'GDP_3'; 'GDP_4'; 'GDP_5'; 'GDP_6'; 'GDP_7'; 'GDP_8'; 'GDP_9'; 'GDP_10'; 'GDP_11'; 'GDP_12'};
+%$ e1.freq = 1;
+%$ e1.init = dynDate(1);
+%$ e2.data = A(:,[1, 13]);
+%$ e2.nobs = 10;
+%$ e2.vobs = 2;
+%$ e2.name = {'GDP_1';'HICP_1'};
+%$ e2.freq = 1;
+%$ e2.init = dynDate(1);
+%$
+%$ % Check results.
+%$ t(1) = dyn_assert(e1.data,a.data);
+%$ t(2) = dyn_assert(e1.nobs,a.nobs);
+%$ t(3) = dyn_assert(e1.vobs,a.vobs);
+%$ t(4) = dyn_assert(e1.name,a.name);
+%$ t(5) = dyn_assert(e1.init,a.init);
+%$ t(6) = dyn_assert(e2.data,b.data);
+%$ t(7) = dyn_assert(e2.nobs,b.nobs);
+%$ t(8) = dyn_assert(e2.vobs,b.vobs);
+%$ t(9) = dyn_assert(e2.name,b.name);
+%$ t(10) = dyn_assert(e2.init,b.init);
+%$ T = all(t);
+%@eof:6
+