Thanks for your answer!
This is the formula.

p = [
     0.2 0.2  0.2 0.2 -0.8
-0.8 0.2  0.2 0.2 0.2
 0.2 0.2 -0.8 0.2 0.2
]
y = [4, 0, 2]
The values I expected  as follows:
［
 0.2 0.2  0.2 0.2 -0.8
-0.8 0.2  0.2 0.2 0.2
 0.2 0.2 -0.8 0.2 0.2
]