Adjugate (adjoint) of a Square Matrix

Calculates the adjugate (adjoint) matrix for a square matrix.

Description

For any n x n matrix, A, with real or complex-valued elements, whether singular or not, its adjugate (also known as its adjoint) matrix, adj(A), is calculated. The svd function is called on to find [u,s,v] = svd(A), and the identity adj(A) = det(u*v')*v*adj(s)*u', which holds even if A is singular, is computed. Tests have shown that the accuracy remains good even up to values of n as large as 32 provided adj(A) does not overflow or underflow matlab's double precision capacity. The definition of the adjugate (adjoint) of matrix A is a matrix in which its element in the i-th row and j-th column is the cofactor of the element of A in the j-th row and i-th column.

• MATLAB release: MATLAB 5.2 (R10)

[A. Z.]

I think you might want to revise the 'adjugate (a.k.a. adjoint)' statements in both the code & its description here. The adjoint of the matrix has *nothing* to do with its adjugate, in general! You're confusing the two notions.

[syam gupta]

good...if uhave code for svd also....plz send it

[kris gopal]

i am not able to run the function due to the error
i donot y it not calling the function size

Error in ==> adjugate at 14
[m,n] = size(A);

hope somone will reply soon

[kris gopal]

i am not able to run the function due to the error
i donot y it not calling the function size

Error in ==> adjugate at 14
[m,n] = size(A);
& i am using Matlab 7.10

hope somone will reply soon

[Joel]

Algebraic question: Why the use of the factor det(u*v') in the documentation? Isn't this factor ALWAYS = 1?

[Michael Hubatka]

@Joel: det(u*v') can also be -1.