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.

2700 questions
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How to Fit a Curve to a Given Model with Constraints?

The input are triples $\left\{ x,y,v\right\}$ where $x,y,v \in \mathbb{R} ^{+}$ I need to find function $f(x,y) = v$ by finding parameters of the following model $f(x,y) = a + bx^c + dy^e $ where $f\left( x,y\right) >0,\forall x,y\in \mathbb{R}…
Lambder
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Parabola from 4 approximate points

I have calculated four approximate points from a sensors to get information. I would like to deduce the closest parabola to my points. The problem is that I can't solve it to get an appropriate result. Here are my four points: $(414, 960),…
Zonata
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Quadratic function as a linear function

I am taking a machine learning course and today we were given an example of regression, with two attributes $x_,x_2$ and $y$ being the real valued outcome. $y$ is a quadratic function of $x_1,x_2$, given as $$y=\alpha_1 x_1^2+\alpha_2 x_2^2+\alpha_3…
Happy Mittal
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How to get the relative contribution of each variable in a difference that forms the numerator?

I am facing a problem that may seem simple at first but with which I struggle. The question relates to economics where I try to see the effect of deficit at time t ($D_t$) onto Output at time t+h ($Y_{t+h}$). That is, I want the multiplier $\Delta…
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what does is mean by 'overfitting' of data?

I have the following equation that is to be estimated: y = a + bA + cB + dC + eF + dG + e and i got 2 other additional variables, fH and gI, that i do not wish to add in.. can i reason this out by saying i want to 'avoid fitting the data model'? or…
Jenny
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Regression Model with (Y,X) non-random?

In regression, we assume that $(X,Y)$ are random variables following some certain distribution. How would the problem change if we do not assume $(X,Y)$ are randoms. Why can we just have $Y=f(X,\epsilon)$, where $(X,Y)$ are non-random, and…
bankrip
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unequal sample size and linear regression

Can i use simple linear regression when there is unequal sample sizes for the dependent and independent variable? Will this be a problem? That is; y=a+bx+epsilon, where y and x have unequal sample sizes.
Jenny
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How to estimate $\alpha$ in $y=(1-\exp(-\alpha x))/(1+\exp(-\alpha x))$?

I have a function $$y=\dfrac{1-\exp(-\alpha x)}{1+\exp(-\alpha x)}$$ where $y$ is not binary. The range of this function is $[-1,1)$. So this does not fit into either logit or probit models. How do I estimate $\alpha$ in such models using some…
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Assumption of Normal Distribution

I have a problem and I do not know when it is crucial and when it is NOT crucial to assume a normal distribution regarding linear regression, for estimates, t-tests, f-tests, confidence intervals and prediction intervals. say we have $$ Y_1 =…
Ara
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How is genetic programming used in Symbolic regression

I am in highschool and have not taken any courses on this. Rather I am working on an outside project. I don't quite understand how Genetic Programming could be used effectively to generate a set of equations to evaluate. My understanding is an…
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Does gradient descent and normal equation give the same answer?

I tried to optimize for a linear regression model using both approaches and they gave me two completely different answers. My sample data set was: df <- data.frame(c(1,5,6),c(3,5,6),c(4,6,8)) Here's the R code I was using to try to calculate…
meri
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Econometrics OLS estimates

I cant seem to use the formula to calculate B1 without knowing xi and yi. Is it possible to calculate using just the variances and covariance? Please help! The classical linear regression model Suppose you believe there is a linear relationship…
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contour plot in multiple linear regression

I have recently saw some examples about contour plots and multiple linear regression, for what I know a countour plot is obtained for having a graphical view of how the weights in a linear regression solution are related to one another. For example…
Lila
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Interpreting linear regression.

I'm not very versed in statistics or anything so I'm in the dark for this. For my biology (Grade 12) class I've been looking at journals and papers and I've seen a lot of graphs expressed in the form 'linear regression'. Wikipedia and other sites…
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Multilinear fit vs Polynomial fit

I have a program that generates some physics data in 1D and 2D functions. In this program, the user defines a number of models that are used to compute a 2D function. That 2D function, and it's first and second derivatives are used with some other…
Jim
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