[Tutor] Is there a library which has this object?

[Yeh]

Hi,
Is there a library which can return some numbers continuously? It will be better to be found in the standard library. If there is not, I'm going to write the function. But, I have no ideas about it yet. (I'm absolutely a beginner.)
I want to have a function which may has three arguments including startNumber, stopNumber and durition.
if startNumber = 0, stopNumber = 2, and durition = 10, it will output 0 to 2 during 10ms continuously, such as:
0.00000...0.00001...0.00002...||until...||2.00000...
and I also want to have another function which may has two arguments including freq and mul.and It will output numbers as an oscillator. (from 0 to 1, and back to 0, and go to -1, and -1 return to 0.)
I'm thinking there is a library, maybe It just is inside standard library. But, I don't know it yet...
So, thanks for all indeed!
Yeh Z