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You're reading from  Python for Secret Agents - Volume II - Second Edition

Product typeBook
Published inDec 2015
Reading LevelIntermediate
Publisher
ISBN-139781785283406
Edition2nd Edition
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Authors (2):
Steven F. Lott
Steven F. Lott
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Steven F. Lott

Steven Lott has been programming since computers were large, expensive, and rare. Working for decades in high tech has given him exposure to a lot of ideas and techniques, some bad, but most are helpful to others. Since the 1990s, Steven has been engaged with Python, crafting an array of indispensable tools and applications. His profound expertise has led him to contribute significantly to Packt Publishing, penning notable titles like "Mastering Object-Oriented," "The Modern Python Cookbook," and "Functional Python Programming." A self-proclaimed technomad, Steven's unconventional lifestyle sees him residing on a boat, often anchored along the vibrant east coast of the US. He tries to live by the words “Don't come home until you have a story.”
Read more about Steven F. Lott

Steven F. Lott
Steven F. Lott
author image
Steven F. Lott

Steven Lott has been programming since computers were large, expensive, and rare. Working for decades in high tech has given him exposure to a lot of ideas and techniques, some bad, but most are helpful to others. Since the 1990s, Steven has been engaged with Python, crafting an array of indispensable tools and applications. His profound expertise has led him to contribute significantly to Packt Publishing, penning notable titles like "Mastering Object-Oriented," "The Modern Python Cookbook," and "Functional Python Programming." A self-proclaimed technomad, Steven's unconventional lifestyle sees him residing on a boat, often anchored along the vibrant east coast of the US. He tries to live by the words “Don't come home until you have a story.”
Read more about Steven F. Lott

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Reducing noise with a simple filter


Is there a way that we can reduce the variability in the output? One possibility to use a moving average of the raw values. Using an Exponentially Weighted Moving Average (EWMA) algorithm will tend to damp out small perturbations in the data, providing a more stable reading.

This moving average is called exponentially weighted because the weights given to previous values fall off exponentially. The immediately previous value is weighted more heavily than the value before that. All values figure into the current value, but as we go back in time, the weights for those old values become very, very small.

The core calculation for a weighted data point, , from the raw data point, , looks like this:

We used a weighting value, w, that expresses the influence of the previous data point on the current data point. If w is one, previous values have no influence. If w is zero, the initial value is the only one that matters and new values are ignored.

The very first data...

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Python for Secret Agents - Volume II - Second Edition
Published in: Dec 2015Publisher: ISBN-13: 9781785283406

Authors (2)

author image
Steven F. Lott

Steven Lott has been programming since computers were large, expensive, and rare. Working for decades in high tech has given him exposure to a lot of ideas and techniques, some bad, but most are helpful to others. Since the 1990s, Steven has been engaged with Python, crafting an array of indispensable tools and applications. His profound expertise has led him to contribute significantly to Packt Publishing, penning notable titles like "Mastering Object-Oriented," "The Modern Python Cookbook," and "Functional Python Programming." A self-proclaimed technomad, Steven's unconventional lifestyle sees him residing on a boat, often anchored along the vibrant east coast of the US. He tries to live by the words “Don't come home until you have a story.”
Read more about Steven F. Lott

author image
Steven F. Lott

Steven Lott has been programming since computers were large, expensive, and rare. Working for decades in high tech has given him exposure to a lot of ideas and techniques, some bad, but most are helpful to others. Since the 1990s, Steven has been engaged with Python, crafting an array of indispensable tools and applications. His profound expertise has led him to contribute significantly to Packt Publishing, penning notable titles like "Mastering Object-Oriented," "The Modern Python Cookbook," and "Functional Python Programming." A self-proclaimed technomad, Steven's unconventional lifestyle sees him residing on a boat, often anchored along the vibrant east coast of the US. He tries to live by the words “Don't come home until you have a story.”
Read more about Steven F. Lott