The signal is binned into time bins with a width ##δt##

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Discussion Overview

The discussion revolves around the concept of "binning window" in the context of data sampling and convolution. Participants explore the relationship between convolving data with a bin function and averaging data values over specified time intervals, specifically focusing on the implications of bin width (δt) in this process.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • One participant seeks clarification on why convolving data with a bin function and binning data into time intervals (δt) are considered equivalent processes.
  • Another participant explains that when δt is set to 1 second, the data values represent averages over that interval rather than being sampled directly at 1-second intervals.
  • A specific convolution with a bin function is highlighted, which is zero outside a certain range and generates a running average of samples within the bin centered at time t.
  • A mathematical expression is proposed to illustrate the equivalence between the average value computation and convolution, suggesting that both processes yield the same result under certain conditions.

Areas of Agreement / Disagreement

Participants express differing levels of understanding regarding the equivalence of convolution and averaging, with some clarifying points while others seek further explanation. The discussion does not reach a consensus on the underlying reasons for this equivalence.

Contextual Notes

The discussion includes assumptions about the properties of the bin function and the nature of the data being analyzed, which may not be fully articulated. There are also unresolved mathematical steps in the proposed equivalence.

arcTomato
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TL;DR
The signal are binned into time bins with a width ##δt##
Hi all.I would like to know about "binning window".
This paper I'm reading says like this.
Why do "convolving the data with the ##b(t)## before the sampling" and "binning into time bins with a width ##δt##" have the same meaning?

スクリーンショット 2019-12-08 11.42.30.png


I know I'm addicted to post to PF 😅
But this forum is so meaningful for me, so please help me if you can!

Thank you
 
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As an example, let's say that δt= 1 sec.
What it is saying is that the data is not being sampled at 1 second intervals.
Rather, each value is an proportional to the average data value across a 1-second interval.

The author is using a convolution to compute that average value across the bin period for each bit.
 
Thank you @.Scott !

That is the point I don't know why.
Why do convolution and computing the average value have same meaning??
 
It's not just any convolution, it's a convolution with the specific bin function they are using - combined with the sampling.
That bin function is zero over most of the range (-##\infty## to ##\infty##) and and N/T within T/2N of the sampling time. The result is that, the function that results from the convolution (fc(t)) will the integral all all data outside the bin multiplied by zero and all data within the bin multiplied by N/T. So that fc(t) generates a running average of the samples that land within a bin centered at time t.

What the author is saying is you are not sampling the original function, but this convolution result (fc(t)).
 
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Thank you @.Scott !
Ok I think I got it.
so, is this right?
##\bar{a}{(t)}=\frac{1}{\delta t} \int_{t-\frac{1}{2 \delta{t}}}^{t+\frac{1}{2\delta{t}}} a{(\tau)} d \tau=\frac{N}{T} \int_{t-\frac{N}{2 T}}^{t+\frac{N}{2 T}} a{(\tau)}d \tau=\int_{-\infty}^{\infty} a{(\tau)} b(t-\tau) d \tau=a{(t)}*b(t)##
 
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