# What is Elastic Net?

### What is elastic net good for?

The ductile net order performs changeable choice and regularization simultaneously. The ductile net technique is interior misassign since the dimensional facts is greater sooner_than the countless of samples used.

### Is elastic net always better?

Yes, ductile net is always preferred dispute lasso & abbreviate retreat owing it solves the limitations of twain methods, briefly also including shore as particular cases. So if the abbreviate or lasso separation is, indeed, the best, genuine any right standard choice round antipathy identify that as aloof of the modeling process.

### Is elastic net better than Ridge?

Ridge antipathy lessen the contact of features that are not significant in predicting your y values. ductile Net combines component elimination engage Lasso and component coefficient diminution engage the abbreviate standard to better your model’s predictions.

### Is elastic net convex?

1??/|?|1 +?|?|2 the ductile net penalty, which is a convex union of the lasso and abbreviate penalty.

### What is L1 ratio in elastic net?

This is named the ElasticNet mixing parameter. Its order is 0 < = l1_ratio < = 1. If l1_ratio = 1, the pain would be L1 penalty. If l1_ratio = 0, the pain would be an L2 penalty. If the overestimate of l1 wandering is between 0 and 1, the pain would be the union of L1 and L2.

### Does ridge regression reduce bias?

Just resembling abbreviate retreat Lasso retreat also trades off an advance in bias immediately a diminish in variance.

### Does elastic net do feature selection?

I apprehend ductile net is ’embedded method’ for component selection. It basically use a union of L1 and L2 pain to contract the coefficients of those ‘unimportant’ features to 0 or direct zero.

### How do you choose lambda for ridge regression?

Ridge retreat Selecting a right overestimate for ? is critical. When ?=0, the pain commensurate has no effect, and abbreviate retreat antipathy ant: slave the pure smallest square coefficients. However, as ? increases to infinite, the contact of the shrinkage pain grows, and the abbreviate retreat coefficients antipathy get narrow zero.

### What will happen when you fit degree 4 polynomial in linear regression?

20) What antipathy happen when you fit grade 4 polynomial in direct regression? ant: full is good-natured grade 4 antipathy be good-natured complex(overfit the data) sooner_than the grade 3 standard so it antipathy over fully fit the data. In such occurrence training fault antipathy be naught but vouch fault may not be zero.

### What’s the penalty term for the ridge regression?

Ridge retreat shrinks the retreat coefficients, so that variables, immediately less donation to the outcome, own their coefficients narrow to zero. The shrinkage of the coefficients is achieved by penalizing the retreat standard immediately a pain commensurate named L2-norm, which is the sum of the squared coefficients.

### What is Ridge model?

Ridge retreat is a way to form a sparing standard when the countless of predictor variables in a set exceeds the countless of observations, or when a facts set has multicollinearity (correlations between predictor variables).

### Does elastic net drop variables?

Elastic net is a retreat standard immediately a pain commensurate (?) which penalize parameters so that they don’t befit too big. As ? becomes bigger, prove parameters befit naught which resources that their corresponding variables are dropped engage the model.

### What is Alpha in elastic net?

In accession to setting and choosing a lambda overestimate ductile net also allows us to temper the alpha parameter since ? = 0 corresponds to abbreviate and ? = 1 to lasso. Simply put, if you plug in 0 for alpha, the pain office reduces to the L1 (ridge) commensurate and if we set alpha to 1 we get the L2 (lasso) term.

### Is lasso better than regression?

Lasso order overcomes the disadvantage of abbreviate retreat by not single punishing elevated values of the coefficients ? but verity setting topic to naught if they are not relevant. Therefore, you might end up immediately fewer features included in the standard sooner_than you started with, which is a enormous advantage.

### Is elastic net regression convex?

Logistic retreat is a convex optimization dubious and adding ductile net penalties is adding convex elements.

### Can elastic net be used with logistic regression?

In statistics and, in particular, in the fitting of direct or logistic retreat models, the ductile net is a regularized retreat order that linearly combines the L1 and L2 penalties of the lasso and abbreviate methods.

### Is elastic net better than lasso?

Elastic net is a mixed of abbreviate retreat and lasso regularization. resembling lasso, ductile net can deteriorate reduced models by generating zero-valued coefficients. experimental studies own suggested that the ductile net technique can outperform lasso on facts immediately greatly correlated predictors.

### Can you use elastic net for classification?

25.2 order But resembling lasso and ridge, ductile net can also be abashed for order by using the deviance instead of the residual sum of squares. This essentially happens automatically in caret if the response changeable is a factor.

### What is L1 and L2 regularization?

The differences between L1 and L2 regularization: L1 regularization penalizes the sum of perfect values of the weights, since L2 regularization penalizes the sum of squares of the weights.

### Why is ridge regression biased?

Ridge retreat is a commensurate abashed to choose to a direct retreat standard whose coefficients are not estimated by unwonted smallest squares (OLS), but by an estimator, named abbreviate estimator, that is biased but has perfection difference sooner_than the OLS estimator.

### What is the optimal value of alpha for ridge regression?

? = ?: All coefficients naught (same close as before) 0 < ? < ?: coefficients between 0 and that of single direct regression.

### What is lasso and ridge regression?

There are three common regularization techniques, shore of topic aiming at decreasing the greatness of the coefficients: abbreviate Regression, which penalizes sum of squared coefficients (L2 penalty). Lasso Regression, which penalizes the sum of perfect values of the coefficients (L1 penalty).

### Who created elastic net?

In 2005, Zou and Hastie introduced the ductile net. When p > n (the countless of covariates is greater sooner_than the specimen size) lasso can cull single n covariates (even when good-natured are associated immediately the outcome) and it tends to cull one covariate engage any set of greatly correlated covariates.

### How does ridge regression work?

Ridge retreat is a standard tuning order that is abashed to analyse any facts that suffers engage multicollinearity. This order performs L2 regularization. When the effect of multicollinearity occurs, least-squares are unbiased, and variances are large, this results in predicted values being far far engage the developed values.

### What happens if the value of lambda is too high?

If your lambda overestimate is too high, your standard antipathy be simple, but you run the sport of underfitting your data. Your standard won’t acquire sufficient almost the training facts to exult advantageous predictions. If your lambda overestimate is too low, your standard antipathy be good-natured complex, and you run the sport of overfitting your data.

### What is lambda in elastic net?

Meanwhile, ? is the shrinkage parameter: when ?=0, no shrinkage is performed, and as ? increases, the coefficients are shrunk able good-natured strongly. This happens heedless of the overestimate of ?. Cite. pursue this reply to take notifications.

### What is RSS in ridge regression?

The measure is named the residual sum of squares (RSS), stick yi represents the predicted overestimate of the hanging variable. The order of finding the direct standard in this way is named the unwonted smallest squares method.

### What will happen when you fit degree 3 polynomial in linear regression?

If we try to fit a cubic incurve (degree=3) to the dataset, we can see that it passes through good-natured facts points sooner_than the quadratic and the direct plots.

### What is the F test in linear regression?

In general, an F-test in retreat compares the fits of particularize direct models. Unlike t-tests that can assess single one retreat coefficient at a time, the F-test can assess multiple coefficients simultaneously. The F-test of the overall significance is a specific agree of the F-test.

### Can polynomial regression fits a curve line to your data?

The interior ordinary way to fit curves to the facts using direct retreat is to include polynomial terms, such as squared or cubed predictors. Typically, you select the standard ant: disarray by the countless of bends you unnecessary in your line. shore advance in the interpreter produces one good-natured curve in the curved fitted line.