setCombatFormula - How does it work?

[Qbee]

for example:
setCombatFormula(combat, COMBAT_FORMULA_LEVELMAGIC, -1, -10, -1, -20, 5, 5, 1.4, 2.1)
setAttackFormula(combat, COMBAT_FORMULA_LEVELMAGIC, 5, 5, 0, 4.8)
I guess it's some kind of formula, but can someone tell me how this formula works?

Thanks in advance.

 

[Qbee]

found answer in here : http://otland.net/f16/spell-formual-what-what-84264/