翻訳と辞書 Words near each other ・ Descendre ・ Descensus ・ Descent ・ Descent (2005 film) ・ Descent (2007 film) ・ Descent (aeronautics) ・ Descent (magazine) ・ Descent (mathematics) ・ Descent (song) ・ Descent (The Outer Limits) ・ Descent (video game) ・ Descent 3 ・ Descent algebra ・ Descent along torsors ・ Descent Cliff ・ Descent direction ・ Descent from antiquity ・ Descent from Genghis Khan ・ Descent from Mount Sinai (Sistine Chapel) ・ Descent from the Cross ・ Descent Glacier ・ Descent II ・ Descent into Chaos ・ Descent into Chaos (Legion of the Damned album) ・ Descent into Chaos (Nightrage album) ・ Descent into Hell (novel) ・ Descent into Madness ・ Descent into the Depths of the Earth ・ Descent Into the Valley of the Planet Smashers ・ Descent of Elizabeth II from William the Conqueror Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Descent direction ： ウィキペディア英語版 Descent direction In optimization, a descent direction is a vector $\backslash mathbf\backslash in\backslash mathbb\; R^n$ that, in the sense below, moves us closer towards a local minimum $\backslash mathbf^$ * of our objective function $f:\backslash mathbb\; R^n\backslash to\backslash mathbb\; R$. Suppose we are computing $\backslash mathbf^$ * by an iterative method, such as line search. We define a descent direction $\backslash mathbf\_k\backslash in\backslash mathbb\; R^n$ at the $k$th iterate to be any $\backslash mathbf\_k$ such that , where $\backslash langle\; ,\; \backslash rangle$ denotes the inner product. The motivation for such an approach is that small steps along $\backslash mathbf\_k$ guarantee that $\backslash displaystyle\; f$ is reduced, by Taylor's theorem. Using this definition, the negative of a non-zero gradient is always a descent direction, as . Numerous methods exist to compute descent directions, all with differing merits. For example, one could use gradient descent or the conjugate gradient method. More generally, if $P$ is a positive definite matrix, then $d\; =\; -P\; \backslash nabla\; f(x)$ is a descent direction at $x$. This generality is used in preconditioned gradient descent methods. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Descent direction」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.