Floor function identity


by eddybob123
Tags: floor, function, identity
eddybob123
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#1
Mar22-13, 12:21 PM
P: 115
Hi all, I found this rather interesting formula online and I was wondering what it means. Could someone explain it to me? All help is appreciated:
http://functions.wolfram.com/Integer...or/16/03/0001/
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rbj
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#2
Mar22-13, 01:23 PM
P: 2,265
Quote Quote by eddybob123 View Post
Hi all, I found this rather interesting formula online and I was wondering what it means. Could someone explain it to me? All help is appreciated:
http://functions.wolfram.com/Integer...or/16/03/0001/
the [itex]\theta[/itex] function is the unit step function, so they are creating a staircase function out of the steps (the infinite summation), and that becomes the floor function.
eddybob123
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#3
Mar22-13, 06:03 PM
P: 115
But what does the z mod 1 mean? I've never seen people use 1 as a modular base before?

micromass
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#4
Mar23-13, 12:18 AM
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Floor function identity


Quote Quote by eddybob123 View Post
But what does the z mod 1 mean? I've never seen people use 1 as a modular base before?
The notation ##z## mod 1 means that you take the element ##x\in [0,1)## such that ##z-x\in \mathbb{Z}##.

If you wish, you can put an equivalence relation ##x\sim y~\Leftrightarrow ~x-y\in \mathbb{Z}## on ##\mathbb{R}##. We can then look at equivalence classes. It won't be the exact same thing as what I said in my first sentence though.
eddybob123
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#5
Mar28-13, 06:17 PM
P: 115
Are there any formulas that compare any positive real number r with floor[r]? I know that their difference is the fractional part of r, which is {r}, but I mean are there any formulas where you can obtain these values systematically?


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