From 6b237eb6c2819273d502c35058ca862730249bfd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Adjemian=20=28Charybdis=29?=
 <stephane.adjemian@univ-lemans.fr>
Date: Fri, 6 Sep 2013 16:49:40 +0200
Subject: [PATCH] =?UTF-8?q?Added=20method=20dynTimeIndex::mpower=20->=20le?=
 =?UTF-8?q?ad-lag=20operators=20=C3=A0=20la=20G-M=20;-).?=
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This method can be used to apply the lead and lag methods an arbitrary number of times to a dynSeries object. For instance, if ts is a dynSeries object, and if we define

>> B = dynTimeIndex()-1;
>> F = dynTimeIndex()+1;

B and F can be used as lag and lead operators and the following syntax:

>> us = ts(F^2);

is equivalent to

>> us = ts.lead(2)

or

>> us = ts.lead.lead
---
 matlab/@dynTimeIndex/mpower.m | 74 +++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 matlab/@dynTimeIndex/mpower.m

diff --git a/matlab/@dynTimeIndex/mpower.m b/matlab/@dynTimeIndex/mpower.m
new file mode 100644
index 000000000..81cfb3cfd
--- /dev/null
+++ b/matlab/@dynTimeIndex/mpower.m
@@ -0,0 +1,74 @@
+function C = mpower(A,B) % --*-- Unitary tests --*--
+
+% C = mpower(A,B)
+%
+% Overloads binary mpower operator (^).
+%
+% INPUTS :
+%  * A, dynTimeIndex object.
+%  * B, integer scalar.
+%
+% OUTPUTS :
+%  * C, dynTimeIndex object.
+%
+% EXAMPLE 1 :
+%
+%  >> B = dynTimeIndex()-1;
+%  >> B
+%  B = <dynTimeIndex: -1>
+%  >> B^4
+%  ans = <dynTimeIndex: -4>
+%  >>
+%
+%  EXAMPLE 2 :
+%  This method can be used to apply the lead and lag methods an arbitrary number of times to a dynSeries object. For instance, if 
+%  ts is a dynSeries object, and if we define
+% 
+%  >> B = dynTimeIndex()-1;
+%  >> F = dynTimeIndex()+1;
+%
+%  B and F can be used as lag and lead operators and the following syntax:
+%
+%  >> us = ts(F^2);
+%
+%  is equivalent to
+%
+%  >> us = ts.lead(2)
+%
+%  or
+%
+%  >> us = ts.lead.lead
+%
+
+% Copyright (C) 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 ~(isa(A,'dynTimeIndex') || isint(B))
+    error(['dynTimeIndex::mpower: Input arguments ''' inputname(1) ''' and ''' inputname(2) ''' must be a dynTimeIndex object and an integer!'])
+end
+
+C = struct();
+C.index = A.index*B;
+C = class(C,'dynTimeIndex');
+
+%@test:1
+%$ a = dynTimeIndex()+1;
+%$ b = a^2;
+%$ t(1) = isa(b,'dynTimeIndex');
+%$ t(2) = isequal(b.index,int8(2));
+%$ T = all(t);
+%@eof:1
\ No newline at end of file