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# Suggestion about data structure to be used for piecewise defined functions.

Claude Moore
Ranch Hand
Posts: 875
8
Good morning to all,

I need any advice about a data structure suitable for defining, in Java, a piecewise function, i.e a function like this:

F(t) = 1 if t in [t0,t1] or t[t2,t3] or.... [tn-1,tn]
0 otherwise.

where t0...tn are given without a specific rule (may be randomly choosed) and are integers.

Campbell Ritchie
Sheriff
Posts: 55351
157
Please explain more about what you need. Did you intend to write t[t2, t3] with the t at the beginning? Are those ordered pairs or something? Is there any ordering or sorting of the pair in the data structure?

Claude Moore
Ranch Hand
Posts: 875
8
Well, I think that a good example may be given by wave function. Let's assume that t is time, so that you have a natural sorting defined
on t values. In a such scenario, f(t) may assume two distinct values, 1 or 0, in different time intervals like [t1,t2] and [t3,t4]..
Let's assume that f(t) assumes 1 as value when a certain system is doing calculations, and 0 when that system is idle. I want to answer to questions like these:
- from a certain time t, for how may minutes system has been up ?
- form a certain time t, has been the system up for at least T minutes ?

and so on..