This task detects the samples that have a substantially lower density than its neighbors and labels the detections as anomalies.
For background on the algorithm used, see Local Outlier Factor Classification.
Example
e = ENVI()
RasterFile = Filepath('qb_boulder_msi', Subdir=['data'], $
Root_Dir=e.Root_Dir)
Raster = e.OpenRaster(RasterFile)
SpectralTask=ENVITask('SpectralIndex')
SpectralTask.INDEX = 'Normalized Difference Vegetation Index'
SpectralTask.INPUT_RASTER = Raster
SpectralTask.Execute
ThresholdROITask=ENVITask('ImageThresholdToROI')
ThresholdROITask.INPUT_RASTER = SpectralTask.OUTPUT_RASTER
ThresholdROITask.ROI_NAME = 'Water'
ThresholdROITask.ROI_COLOR = [0, 0, 255]
ThresholdROITask.THRESHOLD = [-1, -0.10000000149012, 0]
ThresholdROITask.Execute
StatsTask = ENVITask('NormalizationStatistics')
StatsTask.INPUT_RASTERS = Raster
StatsTask.Execute
DataPrepTask = ENVITask('MLTrainingDataFromROIs')
DataPrepTask.INPUT_RASTER = Raster
DataPrepTask.INPUT_ROI = ThresholdROITask.OUTPUT_ROI
DataPrepTask.BACKGROUND_LABELS = []
DataPrepTask.NORMALIZE_MIN_MAX = StatsTask.Normalization
DataPrepTask.Execute
TrainTask = ENVITask('TrainLocalOutlierFactor')
TrainTask.INPUT_RASTER = DataPrepTask.OUTPUT_RASTER
TrainTask.Execute
outputModelUri = TrainTask.OUTPUT_MODEL_URI
print, 'Model URI: ' + outputModelUri
outputModel = TrainTask.OUTPUT_MODEL
print, outputModel.Attributes
Syntax
Result = ENVITask('TrainLocalOutlierFactor')
Input properties (Set, Get): INPUT_RASTERS, LEAF_SIZE, 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.
LEAF_SIZE (optional)
Specify the leaf size. Changing the leaf size can affect the speed of construction and query, as well as the memory required to store the tree. The optimal value depends on the nature of the problem. The default is 30.
MODEL_NAME (optional)
Specify the name of the model. The default is Local Outlier Factor Anomaly Detector.
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, TrainExtraTrees Task, TrainIsolationForest Task, TrainKNeighbors Task, TrainLinearSVM Task, TrainNaiveBayes Task, TrainRandomForest Task, TrainRBFSVM Task