Problem about reading a list

[wangchong01]

Hello, I find that the operation of changing or reading an element from a list (or a matrix, vector) is o(n) which extremely influence my algorithm's running speed. What's more, the GETPIX, PIXON function or calling a user-defined function also needs about 0.5ms (That stops me from the idea of using a array library by storing values to GROB by myself, however, my own array library really gets quicker than the original list averagely when I store about 10000 elements in one list. )! How can avoid these problems?