can i do inverse for array in matlab using for ? how ?

x=[1 2 3; 4 5 6; 7 8 9]

[Walter Roberson]

you could program cofactor expansion

Answer 1

[David Hill]

If det(x) ~=0, then matrix is invertable.Your matrix above is not.

x=[1 2 3;  4 5 6; 7 8 -1];
det(x)

ans = 30.0000

r=rref([x,eye(size(x))]);
Xinv=r(1:3,4:6)

Xinv = 3×3

-1.7667 0.8667 -0.1000 1.5333 -0.7333 0.2000 -0.1000 0.2000 -0.1000

x*Xinv

ans = 3×3

1.0000 0.0000 0 0.0000 1.0000 -0.0000 0.0000 0.0000 1.0000

Xinv*x

ans = 3×3

1.0000 0.0000 0.0000 0.0000 1.0000 0.0000 0 0 1.0000

[John D'Errico]

Note that using det to detemine if a matrix singular is just a bad idea. Use tools like rank, or cond instead.

[3lewwi]

thx bro, but i want it by use ( for )