Mercurial > octave-nkf
changeset 7201:76341ffda11e
[project @ 2007-11-27 18:23:48 by jwe]
| author | jwe |
|---|---|
| date | Tue, 27 Nov 2007 18:23:48 +0000 |
| parents | 12a12ef1f1bc |
| children | ffdbdf53665c |
| files | scripts/linear-algebra/housh.m scripts/linear-algebra/krylov.m src/ov-intx.h |
| diffstat | 3 files changed, 32 insertions(+), 11 deletions(-) [+] |
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--- a/scripts/linear-algebra/housh.m Tue Nov 27 05:51:46 2007 +0000 +++ b/scripts/linear-algebra/housh.m Tue Nov 27 18:23:48 2007 +0000 @@ -19,15 +19,37 @@ ## -*- texinfo -*- ## @deftypefn {Function File} {[@var{housv}, @var{beta}, @var{zer}] =} housh (@var{x}, @var{j}, @var{z}) -## Computes householder reflection vector housv to reflect x to be -## jth column of identity, i.e., (I - beta*housv*housv')x =e(j) -## inputs -## x: vector -## j: index into vector -## z: threshold for zero (usually should be the number 0) -## outputs: (see Golub and Van Loan) -## beta: If beta = 0, then no reflection need be applied (zer set to 0) -## housv: householder vector +## Compute Householder reflection vector @var{housv} to reflect @var{x} +## to be the jth column of identity, i.e., +## +## @example +## @group +## (I - beta*housv*housv')x = norm(x)*e(j) if x(1) < 0, +## (I - beta*housv*housv')x = -norm(x)*e(j) if x(1) >= 0 +## @end group +## @end example +## +## @noindent +## Inputs +## +## @table @var +## @item x +## vector +## @item j +## index into vector +## @item z +## threshold for zero (usually should be the number 0) +## @end table +## +## @noindent +## Outputs (see Golub and Van Loan): +## +## @table @var +## @item beta +## If beta = 0, then no reflection need be applied (zer set to 0) +## @item housv +## householder vector +## @end table ## @end deftypefn ## Author: A. S. Hodel
--- a/scripts/linear-algebra/krylov.m Tue Nov 27 05:51:46 2007 +0000 +++ b/scripts/linear-algebra/krylov.m Tue Nov 27 18:23:48 2007 +0000 @@ -73,7 +73,7 @@ error ("A(%d x %d) must be square", rows (A), columns (A)); endif - [m, kb] = size(V); + [m, kb] = size (V); if (m != na) error("A(%d x %d), V(%d x %d): argument dimensions do not match", na, na, m, kb)