In principle 如果有了整體概念，投奔其他公司，alwasy can寫出 if you

have enough time(related to money). Some algorisms(implemented as codes, very optimized) make the excution much efficient, it probably takes while to figure out if from scratch. Like the commerical math library "numerical recipe", many people just use them to speed up fitting calculation instead of write themself. 

所有跟帖： 

• optimized code is a good point -用戶名被占用了- ♂ (0 bytes) () 12/06/2012 postreply 12:16:10

• 還有些 code 是基於沒公開的內部研究結果的。 -老忽叔叔- ♂ (0 bytes) () 12/06/2012 postreply 17:04:12