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 properties (Set, Get): INPUT_RASTERS, MODEL_NAME, MODEL_DESCRIPTION, OUTPUT_MODEL_URI

Output properties (Get only): OUTPUT_MODEL

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

Methods

This task inherits the following methods from ENVITask. See the ENVITask topic in ENVI Help.

  • AddParameter
  • Execute
  • Parameter
  • ParameterNames
  • RemoveParameters

Properties

This task inherits the following properties from ENVITask:

COMMUTE_ON_DOWNSAMPLE

COMMUTE_ON_SUBSET

DESCRIPTION

DISPLAY_NAME

NAME

REVISION

See the ENVITask topic in ENVI Help for details.

This task also contains the following properties:

INPUT_RASTERS (required)

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

MODEL_NAME (optional)

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

MODEL_DESCRIPTION (optional)

Specify the purpose of the model.

OUTPUT_MODEL (required)

This is a reference to the output model file.

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 property, or set it to an exclamation symbol (!), a temporary file will be created.

Version History

Deep Learning 2.0

Introduced

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