Questions tagged [regression]

This tag is for questions on (linear or nonlinear) regression, which is a way of describing how one variable, the outcome, is numerically related to predictor variables. The dependent variable is also referred to as $~Y~$, dependent or response and is plotted on the vertical axis (ordinate) of a graph.

Regression is a statistical measurement used in finance, investing and other disciplines that attempts to determine the strength of the relationship between one dependent variable (usually denoted by $~Y~$) and a series of other changing variables (known as independent variables).

Types of Regression –

  • Linear regression
  • Logistic regression
  • Polynomial regression
  • Stepwise regression
  • Stepwise regression
  • Ridge regression
  • Lasso regression
  • ElasticNet regression

The two basic types of regression are linear regression and multiple linear regression.

The general form of each type of regression is:

  • Linear regression: $~Y = a + b~X + u~$
  • Multiple regression: $~Y = a + b_1~X_1 + b_2~X_2 + b_3~X_3 + ... + b_t~X_t + u~$

Where:

  • $Y =~$ the variable that you are trying to predict (dependent variable).
  • $X =~$ the variable that you are using to predict Y (independent variable).
  • $a =~$ the intercept.
  • $b =~$ the slope.
  • $u =~$ the regression residual.

There are multiple benefits of using regression analysis. They are as follows:

$1.~$ It indicates the significant relationships between dependent variable and independent variable.

$2.~$ It indicates the strength of impact of multiple independent variables on a dependent variable.

Reference:

https://en.wikipedia.org/wiki/Regression_analysis

This tag often goes along with the tag.

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variance of intercept parmeter in linear regression model

In a Linear Regression model like $Y=\beta_0 +\beta_1X+u$ ,How we can prove that: $\mathrm{Var}(\hat\beta_0)={\bar X^2 \sigma^2\over\Sigma x^2}$ which $x=X-\bar X$
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Is Bilinear regression a form of Multivariate polynomial regression?

I came across a similarity/metric learning method that takes in the form of $x^TWy = z$, where $ x $ and $y$ are real valued vectors. For example, two images. Breaking it into a more familiar form: $ x^TWy = \sum_{ij}w_{ij} x_{i}y_{j} = z $ This…
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Solve for a circle given more than 3 points.

The problem is; given a set of 3 or more point in $\mathbb{R}^2$ that are assumed to approximate some portion of a circular arc, find the "best" center and radius of the circle. The solution I'm considering is: Start with the definition of a…
BCS
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derivation of regression coefficients

I would like to derive the confidence interval for OLS regression but having difficulty in understanding the coefficients itself. Let me state this way, for $Y=aX+b+\epsilon$ where $X, Y, \epsilon$ are random variables with $\epsilon$ zero-mean…
tempx
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Log transformation and regression coefficients

Given two sets of observations $x_i$, $y_i$ that accept the linear regression model $y_i = \beta_{0} + \beta_{1}x_i + e_i$. Define the transformation $\tilde{y} = \log_{100}{(y+|a|)}$, where $a$ is defined to make sure the $log$ is well defined. How…
galah92
  • 356
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Variance- covariance matrix in multivariate regression.

I have a multivariate model with 3 responses and 6 input variables. Three responses models are fitted with different model parameters. In such case how to find variance covariance matrix for output responses
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Regression line

A random sample of size $n$ from a bivariate distribution is denoted by $(x_r,y_r), r=1,2,3,...,n$. Show that if the regression line of $y$ on $x$ passes through the origin of its scatter diagram then $$\bar y\sum^n_{r=1} x_r^2=\bar x \sum^n_{r=1}…
mathnoob123
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Can adding a squared term to your regression increase your heteroskedasticity and Fit?

Lets say you have some data that has a curve linear relationship between your dependent and independent variables, so you decide to add a squared term to your regression in order to better fit your predictions to the data. I noticed that my…
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Regression and the sum of residuals

The answer to the last part provided is The sum of square of residuals is minimum for points lying on the regression line and so cannot be less than 8.8 for any other line. Can somebody please explain what this means? It is almost evident that…
mathnoob123
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Fit predetermined curve to data set

I have a set of $5$ data points $(x, y)$. I need to find two constants ($a$ and $b$), so that the curve $x\cdot y^a=b$ fits my data set. The question states that I can find the constants from the fitting process. However, I'm not sure where to…
edc1591
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Relationship between averages of two variables and the slope of their regression line

Suppose the least-squares regression line for $y$ and $x$ is $y = kx$. Given that $0 < k < 1$, can we say anything about the means of $y$ and $x$? Can we infer that $\bar{y} < \bar{x}$?
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product of two variables fitting problem

I have two time-varying variables X and Y. The product of which is Z(= X*Y). A curve Z' has been fit on Z. So Z'can be described as a product of some new X' and Y'. Where X' = X + dX and Y' = Y + dY. How do I get these new X' and Y'? It looks like a…
Yakku
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From simple to multivariate

I want to estimate regression equation $Y=A(X-\bar X)+b+E$, where these variables are multivariate. $Y$ is matrix. $E$ is error, I need to estimate $A$ and $b$. First I decided to estimate them in simple case: $y=a(x_i-\bar x)+b+e$. Differentiated…
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Regress the mean/stddev of a data set resembling a cumulative gaussian distribution?

If I have a data set of x,y values that I believe resemble a cumulative gaussian distribution, is there an easy way for me to programmatically derive the mean/stddev of the CDF? For example, imagine I have the following x/y value pairs: 1.380211242…
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Equation of line from PPM vs Voltage for sensor.

I have an Electrochemical Hydrogen sensor that I am trying to convert its analogue values to PPM values. I am attempting to follow the datasheet and come up with an equation of the line so I can get a formula into which I put the voltage, and out…