Javascript ~ log 底數 ~ Log base

function custLog(x,base) {

// Created 1997 by Brian Risk. http://brianrisk.com

return (Math.log(x))/(Math.log(base));

}

cool~~~~~~~其實Javascript 內建log函式~~~~

是沒有底數的設定~~~~固定都是e為底數~~~~~~~

因為底數都一樣是e~~~~~~~遇到10為底數怎麼辦@0@~

Log _y z = ( Log _x z ) / ( Log _x y )

從這個式子可以看出.............即使Javascript 只提供e為底數的log運算..........

還是有辦法可以算的~~~~~~~~只能說........以前學得數學都忘光了XD

http://www.geneffects.com/briarskin/programming/newJSMathFuncs.html