Solving Indefinite Integral of Normal Equation

In summary, The conversation discusses a difficult integral that cannot be expressed in elementary form and involves constants \mu and \sigma. The integral can be expressed using the error function, but it cannot be solved directly. However, it can be solved by developing e^{-y^2} as a Taylor series and integrating term by term.
  • #1
Erienion
28
0
I've been trying to integrate the following function but have gotten somewhat stuck doing it. The answer i managed to produce gave some bogan answers.

the integral in question is

[tex]\int e^\frac{-(x-\mu)^2}{(2\sigma)^2}[/tex]

where [tex]\mu[/tex] and [tex]\sigma[/tex] are constants.

its part of the normal equation and I've been trying to write a program to do some calculations with it.
 
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  • #2
The integral can be expressed in terms of the error function, erf(x). Unfortunately, there is no elementary form.
 
  • #3
As far as I can see, by setting [itex]y = x-\mu /2\sigma[/itex], we get the famous [itex]e^{-y^2}[/itex] which doesn't have a primitive. You can however develop [itex]e^{-y^2}[/itex] as a Taylor serie and integrate term by term. You get the (convergant) serie of general term

[tex]a_n=\frac{(-1)^n x^{2n+1}}{(2n + 1)n!}[/tex]
 

1. What is an indefinite integral?

An indefinite integral is a mathematical concept that represents the antiderivative of a function. It is also known as the general integral, and it is the inverse operation of differentiation.

2. What is the normal equation?

The normal equation is a mathematical formula used in statistics and linear algebra to find the optimal parameters for a regression model. It is used to solve for the coefficients that minimize the sum of squared errors in a linear regression problem.

3. Why is it important to solve the indefinite integral of the normal equation?

Solving the indefinite integral of the normal equation allows us to find the exact solution for the optimal parameters in a linear regression model. This is crucial in understanding the relationship between variables and making accurate predictions.

4. What are the steps to solve the indefinite integral of the normal equation?

The steps to solve the indefinite integral of the normal equation are as follows:

  • 1. Take the derivative of the cost function with respect to the parameter vector.
  • 2. Set the derivative equal to 0 and solve for the parameter vector.
  • 3. Substitute the parameter vector into the original cost function to find the minimum value.

5. What are the applications of solving the indefinite integral of the normal equation?

Solving the indefinite integral of the normal equation has various applications in the fields of statistics, economics, and engineering. It is used to analyze and make predictions in linear regression models, as well as in optimization problems such as curve fitting and data smoothing.

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