Cross Validator (Classification)

performs K-fold Cross Validation on a classification dataset.

Overview

Cross Validator (Classification) performs K-fold Cross Validation on a classification dataset.

If you want to perform K-fold Cross Validation on a regression dataset, use the Cross Validator (Regression) Snap instead.


Cross Validator (Classification) Snap dialog

Prerequisites

  • The data from upstream Snap must be in tabular format (no nested structure).
  • This Snap automatically derives the schema (field names and types) from the first document. Therefore, the first document must not have any missing values.

Limitations and known issues

None.

Snap views

View Description Examples of upstream and downstream Snaps
Input The classification dataset. Any Snap that generates a classification dataset document. Examples:
Output Statistical information about the performance of the selected algorithm on the dataset. CSV Formatter/JSON Formatter Snap and File Writer Snap can be used to write the output statistics to file.
Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are:

  • Stop Pipeline Execution Stops the current pipeline execution when the Snap encounters an error.
  • Discard Error Data and Continue Ignores the error, discards that record, and continues with the remaining records.
  • Route Error Data to Error View Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap settings

Note:
  • Suggestion icon (): Indicates a list that is dynamically populated based on the configuration.
  • Expression icon (): Indicates whether the value is an expression (if enabled) or a static value (if disabled). Learn more about Using Expressions in SnapLogic.
  • Add icon (): Indicates that you can add fields in the field set.
  • Remove icon (): Indicates that you can remove fields from the field set.
Field / Field set Type Description
Label String Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if there are more than one of the same Snap in the pipeline.
Label field Required. The label or output field in the dataset that the model will be trained to predict. This value must be a text string representing the categorical type.

Default value: None

Example: $class

Algorithm Required. The classification algorithm that builds the model.
Valid values:
  • Decision Tree
  • K-Nearest Neighbors
  • Logistic Regression
  • Naive Bayes
  • Support Vector Machines
  • Decision Stump
  • Random Forests
  • Multilayer Perceptron
The implementations are from WEKA, an open source machine learning library in Java.

Default value: Decision Tree

Options
The parameters to be applied on the selected algorithm. Each algorithm has a different set of parameters to be configured in this property.

If specifying multiple parameters, separate them with a comma ",".

If blank, the default values are applied for all the parameters.

Valid values: Refer to Options for Algorithms.

Default value: None

Examples:
  • batch_size = 120
  • batch_size = 120, collapse_tree = true
Fold integer Required. The number of folds.

Valid values: 2 through the maximum integer

Default value: 10

Use random seed checkbox If selected, the value of Random seed is applied to the randomizer to get reproducible results.

Default status: Selected

Random seed integer Required. A number used as the static seed for the randomizer.

Default value: 12345

Snap execution Dropdown list Select one of the three modes in which the Snap executes.
Available options are:
  • Validate & Execute. Performs limited execution of the Snap and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime.
  • Execute only. Performs full execution of the Snap during pipeline execution without generating preview data.
  • Disabled. Disables the Snap and all Snaps that are downstream from it.

Troubleshooting

None.