ENVISplitExamples

This function splits examples and class values from an ENVIExamples object into two sets of examples and class values. A common scenario is to use one set for training a classifier and the other set for evaluation. For consistency in both sets, the input examples should be randomized using ENVIShuffleExamples.

The following figures show typical workflows where this function is used:

Example

See Define, Train, and Run the Classifier.

Syntax

Result = ENVISplitExamples(Examples [, Keywords=value])

Return Value

This function returns a two-element array of ENVIExample objects: one with training examples and another with validation examples.

Arguments

Examples

Specify an input ENVIExamples object.

Keywords

ERROR (optional)

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

SPLIT_FRACTION (optional)

Set this keyword to a floating-point value greater than 0 and less than 1.0, indicating the approximate fraction of the input ENVIExamples object to split into the first examples set.

Version History

ENVI 5.4

Introduced

API Version

3.3