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adj.m

by Paul Godfrey

 

25 Jan 1999 (Updated 23 Oct 2006)

No BSD License  

Finds the adjoint of any rectangular matrix

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Description

Finds the adjoint of a matrix of any size.
 
This code was tested under the student edition of matlab version 5.0.
 
Note: This also appears to work under MATLAB 5.2.1

MATLAB release MATLAB 5.2 (R10)
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Comments and Ratings (10)
09 Nov 2002  
26 Apr 2004 rwittick kumar

tiny and efficient

23 Feb 2005 Jason Taillon

Works very well

23 Oct 2005 . .  
03 Aug 2006 muhamet divan  
18 Oct 2006 Luis T.

Does this take into account complex matrices?

In my graduate linear systems analysis course today, our professor today discussed that if a matrix is self-adjoint, then adj(T) = T.

For a real matrix, this means it must be symmetric, and for a complex matrix, it means that it must be hermitian.

For the hermitian and self-adjoint matrix:
T=[0,j;-j,0]

adj(T) should be equal to T

Using this program, it comes out to be conj(T). I believe that should not be the case, unless I'm totally mistaken.

23 Oct 2006 Paul Godfrey

To Luis T. (ltirado@gmail.com):
Your professor is referring to one of the other definitions of "Adjoint"

This program was written to satisfy
A * Inv(A) = I
with Inv(A) = Adj(A)/det(A)
So, for your example, Adj(A) = [0 -j; j 0] ans det(A) = -1
We have A*Adj(A)/det(A) = [1 0; 0 1] = I, as required.

18 Jan 2007 ugl fiser

nice work and easy touse

thanx lot

24 Jul 2007 Silvia A

This program satisfy
A * Inv(A) = I
with Inv(A) = Adj(A)/det(A)
When I tried contrary Inv(A)*A ~= I, the result isn't I anymore.
I think this situation should satisfy both condition.

23 May 2008 ben talbe ahmed  
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Updates
23 Oct 2006

Updated program to find the Adjoint (Adjugate) of non-square matrices.

Tag Activity for this File
Tag Applied By Date/Time
linear algebra Paul Godfrey 22 Oct 2008 06:30:51
adjoint Paul Godfrey 22 Oct 2008 06:30:51
adjugate Paul Godfrey 22 Oct 2008 06:30:51
matrix Paul Godfrey 22 Oct 2008 06:30:51
mathematics Paul Godfrey 22 Oct 2008 06:30:51
 

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