Solving an equation through optimization..........

1 次查看（过去 30 天）
Tinkul
Tinkul 2013-2-25
Y=Ax
y is a mX1 matrix
A is a mXn matrix
x is a nX1 matrix
AA'=I
Here we apply optimization technique to solve x instead of taking inverse of A. Will you explain me why...............Please help me........

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2013-2-25
inverse is only strictly defined for square matrices.
You could use pinv() or the backslash operator ('\')
  7 个评论
显示 5更早的评论
Walter Roberson
Walter Roberson 2013-2-25
http://blogs.mathworks.com/loren/2007/05/16/purpose-of-inv/#2
There are good reasons to not use inv however. The main one is
numerical considerations.
Here is the second paragraph of the description for inv in the documentation:
In practice, it is seldom necessary to form the explicit inverse of a matrix. A frequent misuse of inv arises when solving the system of linear equations.
One way to solve this is with x = inv(A)*b. A better way, from both an execution time and numerical accuracy standpoint, is to use the matrix division operator x = A\b. This produces the solution using Gaussian elimination, without forming the inverse. See \ and / for further information.
Walter Roberson
Walter Roberson 2013-2-25
So EXECUTION TIME and NUMERICAL ACCURACY.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Nonlinear Optimization 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by