changeset 9547:588c6bb6fdcb

update NEWS
author Jaroslav Hajek <highegg@gmail.com>
date Wed, 19 Aug 2009 13:58:50 +0200
parents 1beb23d2b892
children e5f7aee2ab8c
files ChangeLog NEWS
diffstat 2 files changed, 26 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog	Wed Aug 19 13:47:59 2009 +0200
+++ b/ChangeLog	Wed Aug 19 13:58:50 2009 +0200
@@ -1,3 +1,7 @@
+2009-08-19  Jaroslav Hajek  <highegg@gmail.com>
+
+	* NEWS: Update.
+
 2009-08-18  John W. Eaton  <jwe@octave.org>
 
 	* aclocal.m4 (OCTAVE_HDF5_HAS_REQUIRED_API): If test fails, set
--- a/NEWS	Wed Aug 19 13:47:59 2009 +0200
+++ b/NEWS	Wed Aug 19 13:58:50 2009 +0200
@@ -41,6 +41,28 @@
     is overloaded, the handle determines at the time of its reference which
     function to call. A non-overloaded version does not need to exist.
 
+ ** The operation-assignment operators +=, -=, *= and /= now behave more
+    efficiently in certain cases. For instance, if m is a matrix and s
+    a scalar, then the statement
+
+      m += s;
+ 
+    will operate on m's data in-place if it is not shared by another variable,
+    usually increasing both time and memory efficiency.
+    
+    Only the most common combinations are affected, namely:
+    
+      matrix += matrix
+      matrix -= matrix
+      matrix += scalar
+      matrix -= scalar
+      matrix *= scalar
+      matrix /= scalar
+
+   where matrix and scalar belong to the same class. The left-hand side must be
+   a simple variable reference.
+ 
+
 Summary of important user-visible changes for version 3.2:
 ---------------------------------------------------------