Mercurial > octave-antonio
diff doc/interpreter/optim.txi @ 3294:bfe1573bd2ae
[project @ 1999-10-19 10:06:07 by jwe]
author | jwe |
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date | Tue, 19 Oct 1999 10:08:42 +0000 |
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children | a4cd1e9d9962 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/doc/interpreter/optim.txi Tue Oct 19 10:08:42 1999 +0000 @@ -0,0 +1,128 @@ +@c Copyright (C) 1996, 1997 John W. Eaton +@c This is part of the Octave manual. +@c For copying conditions, see the file gpl.texi. + +@node Optimization, Statistics, Differential Equations, Top +@chapter Optimization + +@menu +* Quadratic Programming:: +* Nonlinear Programming:: +* Linear Least Squares:: +@end menu + +@c @cindex linear programming +@cindex quadratic programming +@cindex nonlinear programming +@cindex optimization +@cindex LP +@cindex QP +@cindex NLP + +@node Quadratic Programming, Nonlinear Programming, Optimization, Optimization +@section Quadratic Programming + +@node Nonlinear Programming, Linear Least Squares, Quadratic Programming, Optimization +@section Nonlinear Programming + +@node Linear Least Squares, , Nonlinear Programming, Optimization +@section Linear Least Squares + +@deftypefn {Function File} {[@var{beta}, @var{v}, @var{r}] =} gls (@var{y}, @var{x}, @var{o}) +Generalized least squares estimation for the multivariate model +@iftex +@tex +$y = x b + e$ +with $\bar{e} = 0$ and cov(vec($e$)) = $(s^2)o$, +@end tex +@end iftex +@ifinfo +@code{@var{y} = @var{x} * @var{b} + @var{e}} with @code{mean (@var{e}) = +0} and @code{cov (vec (@var{e})) = (@var{s}^2)*@var{o}}, +@end ifinfo + where +@iftex +@tex +$y$ is a $t \times p$ matrix, $x$ is a $t \times k$ matrix, $b$ is a $k +\times p$ matrix, $e$ is a $t \times p$ matrix, and $o$ is a $tp \times +tp$ matrix. +@end tex +@end iftex +@ifinfo +@var{Y} is a @var{T} by @var{p} matrix, @var{X} is a @var{T} by @var{k} +matrix, @var{B} is a @var{k} by @var{p} matrix, @var{E} is a @var{T} by +@var{p} matrix, and @var{O} is a @var{T}@var{p} by @var{T}@var{p} +matrix. +@end ifinfo + +@noindent +Each row of Y and X is an observation and each column a variable. + +The return values @var{beta}, @var{v}, and @var{r} are defined as +follows. + +@table @var +@item beta +The GLS estimator for @var{b}. + +@item v +The GLS estimator for @code{@var{s}^2}. + +@item r +The matrix of GLS residuals, @code{@var{r} = @var{y} - @var{x} * +@var{beta}}. +@end table +@end deftypefn + +@deftypefn {Function File} {[@var{beta}, @var{sigma}, @var{r}] =} ols (@var{y}, @var{x}) +Ordinary least squares estimation for the multivariate model +@iftex +@tex +$y = x b + e$ +with +$\bar{e} = 0$, and cov(vec($e$)) = kron ($s, I$) +@end tex +@end iftex +@ifinfo +@code{@var{y} = @var{x}*@var{b} + @var{e}} with +@code{mean (@var{e}) = 0} and @code{cov (vec (@var{e})) = kron (@var{s}, +@var{I})}. +@end ifinfo + where +@iftex +@tex +$y$ is a $t \times p$ matrix, $x$ is a $t \times k$ matrix, +$b$ is a $k \times p$ matrix, and $e$ is a $t \times p$ matrix. +@end tex +@end iftex +@ifinfo +@var{y} is a @var{t} by @var{p} matrix, @var{X} is a @var{t} by @var{k} +matrix, @var{B} is a @var{k} by @var{p} matrix, and @var{e} is a @var{t} +by @var{p} matrix. +@end ifinfo + +Each row of @var{y} and @var{x} is an observation and each column a +variable. + +The return values @var{beta}, @var{sigma}, and @var{r} are defined as +follows. + +@table @var +@item beta +The OLS estimator for @var{b}, @code{@var{beta} = pinv (@var{x}) * +@var{y}}, where @code{pinv (@var{x})} denotes the pseudoinverse of +@var{x}. + +@item sigma +The OLS estimator for the matrix @var{s}, + +@example +@group +@var{sigma} = (@var{y}-@var{x}*@var{beta})' * (@var{y}-@var{x}*@var{beta}) / (@var{t}-rank(@var{x})) +@end group +@end example + +@item r +The matrix of OLS residuals, @code{@var{r} = @var{y} - @var{x} * @var{beta}}. +@end table +@end deftypefn