Linear Elastic Net Regression: Options
The Options tab provides options for:
Mode
This selection provides options for specifying one of the following modes:
- Fit with specified L1 ratio and alpha
- When you select this mode, a single model is fitted to the training data by using specified L1
ratio and alpha regularization values. This is the default. If a partition is specified, the single
or final model that is fitted is applied to the held-out test data to estimate out-of-sample
performance.
Under Plot, plots of observed and/or residuals versus predicted values can be selected.
Under Save, you can specify predicted values and residuals to save.
- Trace plot
- When you select this mode, three plots for the training data are displayed as a function of
alpha for the specified set of alpha values:
- A trace plot of regression coefficients.
- A plot of R2.
- A plot of mean squared error (MSE).
Although the partition is honored, no results for held-out test data are provided because no final model results from this mode.
- L1 ratio and/or alpha selection via cross validation
- When you select this mode, a grid search with cross validation to evaluate models is performed,
and the best ratio and alpha values are chosen based on the best average R2 over the
validation folds. The Number of cross validation folds field can be used to
change the default value of five splits or folds for cross validation. If a partition is specified,
the single or final model that is fitted is applied to the held-out test data to estimate
out-of-sample performance.
Under Display, you can select to show basic information about only the model with the chosen value of ratio and alpha (Best), basic information about all models compared (Compare models), or complete information on all splits or folds for all models (Compare models and folds). Best is the default.
Under Plot, plots of mean R2 and/or MSE over validation folds can be selected. Plots of observed and/or residuals versus predicted values can also be selected.
Under Save, you can specify predicted values and residuals to save.
- Specify individual L1 ratios
- When you select this mode for the Fit with specified L1 ratio and alpha
or Trace plot mode, you can specify a single L1 penalty ratio value. When
selected for the L1 ratio and/or alpha selection via cross validation mode,
you can specify multiple values.
- Specify grid of alpha values
- When you select this mode for the L1 ratio and/or alpha selection via cross
validation mode, a grid of unique alpha values can be specified from a
Start value (
value1
) to an End value (value2
) with the increment of By (value3
). If specified, only one valid set of [value1 TO value2 BY value3
] is allowed. It must satisfy that0 ≤ value1 ≤ value2 ≤ 1
. In cases wherevalue1 = value2
, it is equivalent to specifying a singlevalue1
, regardless ofvalue3
.Plots are displayed by using the specified metric for the horizontal X axes of the varying alpha values.
- Specify individual alphas
- When you select this mode for the Fit with specified L1 ratio and alpha
mode, you can specify a single alpha regularization value. When selected for the Trace
plot or L1 ratio and/or alpha selection via cross validation
mode, you can specify multiple values.
- Specify grid of alpha values
- When you select this mode for the Trace plot or L1 ratio
and/or alpha selection via cross validation mode, a grid of unique alpha values can be
specified from a Start value (
value1
) to an End value (value2
) with the increment of By (value3
). If specified, only one valid set of [value1 TO value2 BY value3
] is allowed. It must satisfy that0 ≤ value1 ≤ value2 ≤ 1
. In cases wherevalue1 = value2
, it is equivalent to specifying a singlevalue1
, regardless ofvalue3
.The Alpha metric for ranges of values can be either Linear or Base 10 logarithmic (10 is raised to the power of specified values).
Plots are displayed by using the specified metric for the horizontal X axes of the varying alpha values.
Criteria
Controls analyses.
- Include intercept
- This criterion includes an intercept in the fitted model(s). Note that the extension procedure does not center or standardize the dependent variable, and the intercept is not penalized during estimation.
- Standardize predictors
- Standardizes all independent variables.
- Number of cross validation folds
- The number of splits or folds for cross validation evaluation of models. Must be a positive integer value greater than 1. The default is 5.
- Python random state
- The value of the random_state setting in Python used while you perform cross validation evaluation of models. It allows replication of results that involve pseudo-random numbers. The value must be an integer in the range of 0 to 232-1. The default is 0.
- Time limit (minutes)
- The number of minutes allowed for the model computations to run. If you specify 0, the timer is turned off. The default value is 5.
Display
This option specifies the amount of output to display for the L1 ratio and/or alpha selection via cross validation mode.
- Best
- Displays only basic results for the chosen best model. This is set by default.
- Compare models
- Displays basic results for all evaluated models.
- Compare models and folds
- Displays full verbose results for each split or fold for each evaluated model.
Plot
This option specifies plots of observed or residual values versus predicted values, and with cross validation, specification of plots of average mean squared error (MSE) and/or average R2 over cross validation folds versus alpha values.
- Average crossvalidation mean squared error (MSE) versus alpha
- For the L1 ratio and/or alpha selection via cross validation mode, displays a line plot of average MSE over cross validation folds versus alpha for the specified or selected best L1 ratio value. For the Trace plot mode, a similar plot is automatically produced based on the complete training data.
- Average cross-validation R Square versus alpha
- For the L1 ratio and/or alpha selection via cross validation mode, displays a line plot of average R2 over cross validation folds versus alpha for the specified or selected best L1 ratio value. For the Trace plot mode, a similar plot is automatically produced based on the complete training data.
- Observed versus Predicted
- Displays a scatterplot of observed versus predicted values for the specified or best model.
- Residuals versus Predicted
- Displays a scatterplot of residuals versus predicted values for the specified or best model.
Save
Specifies variables to save to the active data set.
- Predicted values
- Save predicted values from the specified or best model to the active data set. You can also specify a Custom variable name.
- Residuals
- Save residuals from the specified or best model predictions to the active data set. You can also specify a Custom variable name.