From f4c01a43bc2882e7fd18f3cd82344fff9644088c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Adjemian=20=28Charybdis=29?=
 <stephane.adjemian@univ-lemans.fr>
Date: Thu, 5 Sep 2013 17:46:04 +0200
Subject: [PATCH] Introduce new syntax for shifting backward or forward a
 dynSeries object.

Suppose that ts is a dynSeries object and let

t = dynTimeIndex();

Then

us = ts.lag();  <=>  us = ts(t-1);

us = ts.lag(2);  <=>  us = ts(t-2);

us = ts.lead();  <=>  us = ts(t+1);

Added corresponding unitary test.
---
 matlab/@dynSeries/subsref.m | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/matlab/@dynSeries/subsref.m b/matlab/@dynSeries/subsref.m
index b129662c3..63847ccac 100644
--- a/matlab/@dynSeries/subsref.m
+++ b/matlab/@dynSeries/subsref.m
@@ -151,6 +151,17 @@ switch S(1).type
         else
             error(['dynSeries::subsref: dynSeries object ''' inputname(1) '''  is not empty!'])
         end
+    elseif isa(S(1).subs{1},'dynTimeIndex')
+        % shift backward/forward (lag/lead) dynSeries object
+        shift = S(1).subs{1}.index;
+        if shift>0
+            B = feval('lead',A,shift);
+        elseif shift<0
+            B = feval('lag',A,-shift);
+        else
+            % Do nothing.
+            B = A;
+        end
     elseif isa(S(1).subs{1},'dynDates')
         % Extract a subsample using a dynDates object
         [junk,tdx] = intersect(A.time.time,S(1).subs{1}.time,'rows');
@@ -532,3 +543,25 @@ end
 %$
 %$ T = all(t);
 %@eof:12
+
+%@test:13
+%$ try
+%$     data = transpose(0:1:50);
+%$     ts = dynSeries(data,'1950Q1');
+%$     a = ts.lag;
+%$     b = ts.lead;
+%$     tt = dynTimeIndex();
+%$     c = ts(tt-1);
+%$     d = ts(tt+1);
+%$     t(1) = 1;
+%$ catch
+%$     t(1) = 0;
+%$ end
+%$
+%$ if t(1)>1
+%$     t(2) = (a==c);
+%$     t(3) = (b==d);
+%$ end
+%$
+%$ T = all(t);
+%@eof:13
\ No newline at end of file