This task implements learning based on the k nearest neighbors of each query point, where k is an integer value specified by the user in the form of ROI class values.

For background on the algorithm used, see K-Neighbors Classification.

Example


; Start the application
e = ENVI()
 
; Open an input raster file
RasterFile = Filepath('qb_boulder_msi', Subdir=['data'], $
  Root_Dir=e.Root_Dir)
Raster = e.OpenRaster(RasterFile)
 
; Open an input ROI file
ROIFile = Filepath('qb_boulder_roi.xml', Subdir=['data'], $
Root_Dir=e.Root_Dir)
ROI = e.OpenROI(ROIFile)
 
; Get the statistics task from the catalog of ENVITasks
StatsTask = ENVITask('NormalizationStatistics')
 
; Define inputs
StatsTask.INPUT_RASTERS = Raster
 
; Run the task
StatsTask.Execute
 
; Get the data prep task from the catalog of ENVITasks
DataPrepTask = ENVITask('MLTrainingDataFromROIs')
 
; Define inputs
DataPrepTask.INPUT_RASTER = Raster
DataPrepTask.INPUT_ROI = ROI
DataPrepTask.BACKGROUND_LABELS = ['Disturbed Earth', 'Water']
DataPrepTask.NORMALIZE_MIN_MAX = StatsTask.Normalization
DataPrepTask.Execute
 
; Get the training task from the catalog of ENVITasks
TrainTask = ENVITask('TrainKNeighbors')
 
; Define inputs
TrainTask.INPUT_RASTER = DataPrepTask.OUTPUT_RASTER
 
; Run the task
TrainTask.Execute
 
; Output model metadata
outputModelUri = TrainTask.OUTPUT_MODEL_URI
print, 'Model URI: ' + outputModelUri
 
outputModel = TrainTask.OUTPUT_MODEL
print, outputModel.Attributes, /IMPLIED

Syntax


Result = ENVITask('TrainKNeighbors')

Input parameters (Set, Get): INPUT_RASTERS, MODEL_DESCRIPTION, MODEL_NAME, MODEL_VERSION, OUTPUT_MODEL_URI, REMOVE_OUTLIERS

Output parameters (Get only): OUTPUT_MODEL

Parameters marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Parameters marked as "Get" are those whose values you can retrieve but not set.

Input Parameters


INPUT_RASTERS (required)

Specify one or more preprocessed training rasters to be used for training.

MODEL_DESCRIPTION (optional)

Specify the purpose of the model.

MODEL_NAME (optional)

Specify the name of the model. The default is K-Neighbors Supervised Classifier.

MODEL_VERSION (optional)

Specify a semantic version format (MAJOR.MINOR.PATCH) for the trained model (for example, 1.0.0). The version may indicate the following:

  • MAJOR: Breaking changes to the model
  • MINOR: Compatibility or new features
  • PATCH: Minor adjustments

OUTPUT_MODEL_URI (optional)

Specify a string with the fully qualified filename and path of the associated OUTPUT_MODEL. If you do not specify this parameter, or set it to an exclamation symbol (!), a temporary file will be created.

REMOVE_OUTLIERS (optional)

The default of true removes outliers using histogram stretching to increase the minimum and decrease the maximum data values. If set to false, use the true minimum and maximum data ranges to normalize the data.

Output Parameters


OUTPUT_MODEL

This is a reference to the output model file.

Methods


Execute

Parameter

ParameterNames

See ENVI Help for details on these ENVITask methods.

Properties


DESCRIPTION

DISPLAY_NAME

NAME

REVISION

See the ENVITask topic in ENVI Help for details.

Version History


Machine Learning 2.0

Introduced

Machine Learning 3.0.1

Added REMOVE_OUTLIERS parameter

Machine Learning 6.2

Added the MODEL_VERSION and OUTPUT_MODEL_URI parameters

See Also


ENVI Machine Learning Algorithms Background, TrainBirch Task, TrainExtraTrees Task, TrainIsolationForest Task, TrainLinearSVM Task, TrainLocalOutlierFactor Task, TrainMiniBatchKMeans Task, TrainNaiveBayes Task, TrainRandomForest Task, TrainRBFSVM Task