Calculate the standard deviation of Gaussian distribution ,thanks

In summary, the standard deviation of a Gaussian distribution is calculated by taking the square root of the sum of the squared differences between each data point and the mean, divided by the total number of data points. It is a measure of the spread of data points from the mean, and a larger standard deviation results in a wider and flatter curve while a smaller standard deviation results in a narrower and taller curve. The standard deviation cannot be negative and is not the same as the variance, which is calculated by squaring the standard deviation.
  • #1
chener
5
0
Given a one-dimensional Gaussian distribution, distributed as following:

f (x) = exp (-x ^ 2 / (2q)) / q / √ (2pi)

proof which q is the standard deviation

Thanks !The standard deviation is defined by:
http://www.mathsisfun.com/data/standard-deviation-formulas.html
 
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  • #2
chener said:

That link defines the "sample standard deviation".

The number 'q' is the "population standard deviation". The definition of "population standard deviation" ( which is the "standard deviation of a random variable") involves doing an integration. Are you familiar with calculus?
 
  • #3
Misplaced schoolwork-type question with no effort shown. Thread is closed.
 

1. What is the formula for calculating the standard deviation of a Gaussian distribution?

The formula for calculating the standard deviation of a Gaussian distribution is:

σ = √( ∑(x-μ)^2 / N )

where σ is the standard deviation, μ is the mean, x is each individual data point, and N is the total number of data points.

2. How is the standard deviation related to the shape of a Gaussian distribution?

The standard deviation is a measure of how spread out the data points are from the mean in a Gaussian distribution. A larger standard deviation indicates a wider spread of data points, resulting in a flatter and wider-shaped curve. Conversely, a smaller standard deviation indicates a tighter spread of data points, resulting in a taller and narrower-shaped curve.

3. Can the standard deviation of a Gaussian distribution be negative?

No, the standard deviation of a Gaussian distribution cannot be negative. It is always a positive value, as it represents the distance from the mean. If the standard deviation were to be negative, it would imply that some data points are located to the left of the mean, which is not possible for a Gaussian distribution.

4. How does changing the standard deviation affect the shape of a Gaussian distribution?

Changing the standard deviation directly affects the shape of a Gaussian distribution. A larger standard deviation results in a wider and flatter curve, while a smaller standard deviation results in a narrower and taller curve. The standard deviation also determines the spread of data points and the likelihood of obtaining a certain value from the distribution.

5. Is the standard deviation the same as the variance in a Gaussian distribution?

No, the standard deviation and variance in a Gaussian distribution are not the same. The variance is calculated by squaring the standard deviation, and it represents the average squared distance from the mean. While the standard deviation is measured in the same units as the data, the variance is measured in squared units, making it less interpretable compared to the standard deviation.

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