Custom Sigma method

small correction, ans += ... not ans =

otherwise you get the maximum value of j in f(j) and not the entire array of j

Hmmm? You mean 'sigma' as in 'summation' right? There is a built in method for that. It think it's only for later Ruby versions though. You can also do it using inject/reduce.

Also: Passing the function as a string to be evaluated? Tsk tsk... That's a bad practice ya know? There is a better way... Blocks are your friend!

Another helpful message from Kayzee the programing snob! :3

I could not find a sigma method. ya its sums.

I am not sure I ever heard it be called a 'sigma method' before, though it makes a degree of sense I guess. But yeah, that's what inject is for more or less.

no clue what you're on about

I mean that if you want to sum an array like that in ruby you usually do something like this:

[1,2,3,4,5].inject(0) {|sum, n| sum+n }

Unless what you really want to do are limits?

ok. so no. the f(j) = O(n^2)

k  so the sum series is not the array.

I honestly don't really understand what you are doing there then... I guess looking at it, it looks like you are just looking at the array's size and not it's contents. Huh... f(j) = O(n^2) you say? Are you perhaps doing a rough calculation of how a function's time/memory requirements scale with it's input? Actually... Isn't that a type of limit?

basically all the algorithms I learned for first two chapters involve arrays, sorting, searching. And wanted to see how a particular method was compared to another, based on the book's array suggestions

Hehe... Oh I see! I guess I was mistaken then. I am sorry if I was a bother. Though I still likely would have used blocks and not eval... But eh.

ah, the function is also intended as internal use only, so there can't be chance of the player breaking it.

It's the principle of the thing!