Example

> M = rand(4,4)
 M =
        1     0.0369      0.204       0.91  
    0.975      0.162      0.167      0.112  
    0.647      0.665      0.655      0.299  
    0.333     0.0847      0.129      0.265  
> a = factor(M)
   lu           pvt          rcond        
> a.lu
        1     0.0369      0.204       0.91  
    0.647      0.641      0.523      -0.29  
    0.975      0.196     -0.134     -0.718  
    0.333      0.113    -0.0132    -0.0144  
> a.pvt
        1          3          3          4  
> a.rcond
 0.000436