Levi Profile picture
Oct 21, 2023 9 tweets 3 min read Read on X
How to describe distribution?

Skewness 🧵 https://www.allaboutcircuits.com/technical-articles/understanding-the-normal-distribution-parametric-tests-skewness-and-kurtosis/
Skewness is a measure of the asymmetry of a distribution.

Distribution is symmetric if it looks the same to the left and right of the center point.

Skewness differentiates extreme values in one versus the other tail.

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The formula to get the skewness:

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Left skew / Negative skew:

Negative values for the skewness indicate data that are skewed left - the left tail is long relative to the right tail.

The mean of a left-skewed distribution is almost always less than its median.

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Right skew / Positive skew:

Positive values for the skewness indicate data that are skewed right - the right tail is long relative to the left tail.

Here the mean is almost always greater than the median.

Because extreme values affect the mean more than the median.

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Zero skew:

When a distribution has zero skew, it is symmetrical. Its left and right sides are mirror images.

The skewness for a normal distribution is zero.

The mean = median

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Pandas has a built-in method to calculate the skewness of the data.

Since the value is negative, the data is skewed to the left - the left tail is slightly longer than the right tail.

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That's it for today.

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Like/Retweet the first tweet below for support, Thanks 😉

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Apr 20, 2024
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Look at a random group of 1 million people.

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Weights and Biases are the engines in Neural Networks.

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When data is flowing between different neurons or layers, it is not just going from A to B.

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Here is how they do it:
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5 Regression Algorithms you should know

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Perceptron, the simplest Neural Network.

I explain how it works. Image
The Perceptron is a binary classifier.

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The two classes are usually represented with 0 and 1. I will use this notation in this thread.
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- It takes several inputs
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If the result is less than or equal to 0, the output is 0.

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Let's see an example 🔽 Image
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