INV Invert Matrix

Usage

Inverts the argument matrix, provided it is square and invertible. The syntax for its use is

   y = inv(x)

Internally, the inv function uses the matrix divide operators. For sparse matrices, a sparse matrix solver is used.

Example

Here we invert some simple matrices

--> a = randi(zeros(3),5*ones(3))

a = 
 5 3 3 
 4 1 3 
 5 2 5 

--> b = inv(a)

b = 
    0.0909    0.8182   -0.5455 
    0.4545   -0.9091    0.2727 
   -0.2727   -0.4545    0.6364 

--> a*b

ans = 
    1.0000    0.0000   -0.0000 
    0.0000    1.0000         0 
    0.0000    0.0000    1.0000 

--> b*a

ans = 
    1.0000    0.0000         0 
    0.0000    1.0000         0 
    0.0000   -0.0000    1.0000