Mercurial > hg > octave-lyh
diff NEWS @ 9717:4fd71e875120
update NEWS
author | Jaroslav Hajek <highegg@gmail.com> |
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date | Mon, 12 Oct 2009 14:40:55 +0200 |
parents | 2c5169034035 |
children | 97d683d8b9ff |
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--- a/NEWS +++ b/NEWS @@ -81,37 +81,6 @@ ** Octave now allows user-defined subsasgn methods to optimize out redundant copies. For more information, see the manual. - ** When evaluating nested expressions, Octave will now make some attempts to - reuse temporary arrays instead of allocating new one for each result. - For instance, the expression - - -(2*a + b) - - where a and b are arrays, will now be done like this: - - allocate c - for all i: c(i) = 2*a(i) - for all i: c(i) = c(i) + b(i) - for all i: c(i) = -c(i) - c is the result - - previously, a new temporary was allocated for each intermediary result - - allocate c - for all i: c(i) = 2*a(i) - allocate d - for all i: d(i) = c(i) + b(i) - deallocate c - allocate e - for all i: e(i) = -d(i) - deallocate d - e is the result - - This will result in memory saving and less allocations, as well as a modest - performance improvement on most platforms. - Currently, only temporaries on the left-hand side of the operator can be reused, - as well as temporaries subject to unary operators - and !. - ** More efficient matrix division handling. Octave is now able to handle the expressions M' \ v @@ -142,6 +111,12 @@ Matrix division is similarly affected. + ** More efficient handling of triangular matrix factors returned from factorizations. + The functions for computing QR, LU and Cholesky factorizations will now automatically + return the triangular matrix factors with proper internal matrix_type set, so that it + won't need to be computed when the matrix is used for division. + + Summary of important user-visible changes for version 3.2: ---------------------------------------------------------