Custom Sort(0.2*relervanceScore + 0.8*numberic_field_value)

[刘健]

Hello:

     I want to get final search result sorted by (0.2*relervance score + 0.8* 
specified_numberic_field) .

I have known that if I use “bf”in edismax (e.g. bf=field(value)), I can get a 
result sorted by(relervance sore + field(value)) ,but I don`t know how to 
Implement the result sorted by (0.2*relervance score + 
0.8*specified_numberic_field) .

Thanks!

Leo