Example

> a = rand(4,4)
 a =
    0.957      0.367      0.641      0.252  
     0.89      0.638      0.245      0.955  
    0.279       0.18      0.284      0.921  
     0.42      0.589      0.869      0.376  
> b = lu(a)
   l            pvt          u         
> b.l
 l =
        1          0          0          0  
    0.439          1          0          0  
     0.93      0.693          1          0  
    0.291      0.171    0.00416          1  
> b.u
 u =
    0.957      0.367      0.641      0.252  
        0      0.428      0.589      0.265  
        0          0     -0.758      0.537  
        0          0          0        0.8  
> b.pvt
 pvt =
        1          0          0          0  
        0          0          1          0  
        0          0          0          1  
        0          1          0          0  
> b.pvt*b.l*b.u
    0.957      0.367      0.641      0.252  
     0.89      0.638      0.245      0.955  
    0.279       0.18      0.284      0.921  
     0.42      0.589      0.869      0.376