Questions tagged [linear-models]

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Does the appliance of R-squared to non-linear models depends on how we calculate it?

Does the appliance of R-squared to non-linear models depends on how we calculate it? $R^2 = \frac{SS_{exp}}{SS_{tot}}$ is going to be an inadequate measure for non-linear models since an increase of $...
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1answer
26 views

The effect of the λ in the Ridge regression

Why by increasing value of λ in Ridge estimator the slope of the line is decreasing? How exactly λ affects to the y = kx + b?
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2answers
131 views

How to visualize optimization problems' feasible region?

Is there any tool to visualize the feasible region when given a set of Linear equations (equalities and inequalities). If not, can anyone suggest a way to visualize it? If I am going to do it myself ...
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0answers
42 views

Understanding the math behind linear classification [closed]

For example we have $X$ train data, $y$ and $w$ Our margin is $M = y_i \langle w, x_i \rangle$ If $M_i > 0$ classifier return True predict and otherwise, if $M_i < 0$ we get False predict. How ...
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0answers
35 views

Does linear kernel make SVM a linear model?

I have deleloped several SVR models for my case study using the linear kernel, and those models were optimized using the RMSE as criterion. Now Im searching for additional evaluation metrics and it ...
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14 views

Linear models: Imputing missing not at random

This question is a continuation of a similar question for linear models instead of Tree-based model. Given that linear models (e.g. lasso, ridge, Linear regression, elastic net, etc.) can't handle ...
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0answers
11 views

linear mixed modelling- Zi in model matrix

Hi I am trying to learn linear mixed modelling. In the matrix form of the model $Y_i = X_i \beta + Z_i \mu_i + \epsilon_i$, how do we calculate is $Z_i$? The model is defined in the picture attached. ...
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1answer
16 views

How to make a linear model with a constant value in R?

I'm working on an unassessed homework problem from unpublished course notes of a statistics module from a second year university mathematics course. I'm trying to plot a 2-parameter full linear model ...
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28 views

What is the Intuition behind weight vector W which is normal to the plane? Is the weight vector W same as the W which is normal to the plane π?

In an interview, I was asked the intuition behind the weight vector. I told the weight vector is a vector which we try to minimize to a local minima with the help of regulariser so we don't overfit. ...
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1answer
131 views

Can absolute or relative contributions from X be calculated for a multiplicative model? $\log{ y}$ ~ $\log {x_1} + \log{x_2}$

(How) can absolute or relative contributions be calculated for a multiplicative (log-log) model? Relative contributions from a linear (additive) model E.g., there are 3 contributors to $y$ (given by ...
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0answers
48 views

How can I compare a NN model and a linear regression?

I have a small dataset (1500 rows) and to predict the imbalanced target, I am running two linear models (linear regression and lasso) and one nonlinear model (Neural Network) on it. I am using Area ...
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1answer
149 views

what is difference between Logistic regression and SGDClassifier with log loss OR SVM and SGDClassifer with hinge loss?

Can we just use SGDClassifier with log loss instead of Logistic regression, would they have similar results ?