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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General nonlinear least squares?

I'm looking to solve some kind of generalized nonlinear least squares problem, I think. So for some background, lets say I have an ordinary nonlinear least squares problem. That is, a set of data points ${(x_i,y_i)}$, an objective function…
janneb
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Derive a formula of a specific curve

I have this curve And I know that the first point is $$A(0,5)$$ and the last point is $$C(1650,9.5)$$ The point almost at the center where the curve changes (if you look close, you can see a green dot) is $$B(1000,8.5)$$ There is a way to derive a…
Kahel
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Finding a function given a set of points, without knowing what type of function

If I have a set of points, but am not sure what type of function they could fit, is there a way to find that function? Here are a few of the points... (0,0) (3,30) (4,114) (5,434) (6,1655) I ran it through an exponential regression calculator…
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Derivation Regression Factor Analysis

can someone derive the last formula for the variance ? I dont get the result and its in the script of my university: " (ii) Regression methodology: now assume the model $\mathrm{x}=\boldsymbol{\mu}+\mathrm{Lf}+\boldsymbol{\epsilon}$, such…
mth
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Minimizing squared error between several datasets

I'm just starting to get back into math for some computer programs i am writing and I've run into a complex regression-like problem. Its been a long time since grade school and i don't even know which field of mathematics to look into for this.…
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Sinusoidal regression sample

I am trying to develop in java the sinusoidal regression algorithm described by Jean Jacquelin: https://fr.scribd.com/doc/14674814/Regressions-et-equations-integrales For my use, the '$a$' parameter is useless. So I modified equations 1 to 24 (pages…
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Proving the equality of two expressions

The context of the following identity is in the Classical Normal Linear Regression Model, ie, $\boldsymbol{y} = \boldsymbol{X}\boldsymbol{\beta}+ \boldsymbol{u}$ where $\boldsymbol{u}$ is a $n \times 1$ matrix and $u_i \sim iid.N(0, \sigma^2)$ for…
Trts
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High values of r^2 and residual sum of squares

The table below shows the average time T it takes for a computer to sort n items n (items) 5 10 50 100 500 1000 T (microseconds) 17.4 28.2 157.6 305.5 2812.9 9701.0 Use your graphics calculator to fit…
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Fitting exponential curve to data containing repeating $x$-values

As the title states, that's what I am trying to do. I originally was following the solution to another post that was asking about the same question and this worked, until I started having data that had repeating x-values (But still different…
Sophia
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Can I find the function of X and Y that best predicts the value of Z given a few data points?

Given the following data points X Y Z 18.23 3 80 42.2 5.5 600 377.30 52.04 900 6835.86 646.91 17 000 X Y Z 250 20 ? Can I find the function of X and Y that best predicts the value of Z? In my (basic) understanding, a…
lami
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Single regression vs. multi-regression

I have three columns of data, Y, X1, X2 and I want to do single and multi regression on them. For single regression the result is fine: REG(Y, X1) ==> ŷ = -0.87027X - 0 REG(Y, X2) ==> ŷ = 0.30389X - 0.0003 As you can see for X1, the…
mahmood
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Defining SARIMA Equation in a "simpler" way.

I am trying to understand how to write a SARIMA equation in a way that is more easily understood, for me. The only specification I can find for the model looks like: $(1-\phi_1)(1-\Phi_1^4)(1-B)(1-B^4)y_t =…
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How do you determined what variables to remove from a regression model

I apologise for how vague this question may appear but I am not finding any resources online to help with this issue. I have a data frame loaded into R and split into two separate data frames: training and testing. My data is around diabetes and has…
Pthyon
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Ground truth divided by prediction vs. mean average error for evaluation of a regression model.

I am familiar with the mean absolute error (MAE) for the evaluation of performances in a regression model. Given a set of ground truth (GT) values $y_i$, and a set of the model evaluated values $\hat{y}_i$, the mean average error $E_{mae}$ is…
havakok
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Unobserved random error is not independent of X

My statistics professor mentioned in the class that we can generally model the regression relationship as $y = f(x) + \epsilon$ where $E(\epsilon|x) = 0$. He told us that $\epsilon$ is not independent of $x$ and a way to show that is through…