ENVIAgCalculateZoneMetricsTask

This task calculates statistics on individual zones contained in an ENVIAgZones object.

This task is part of ENVI Crop Science, which requires a separate license and installation.

Example

This example uses a DEM as the basis for splitting a field into five management zones. The example uses ENVIAgCreateZonesTask to create the zones, then it calculates and prints metrics for each zone.

; Start the application

e = ENVI(/HEADLESS)

; Open a DEM file

File = Filepath('FieldDEM.dat', $

  Subdir=['data','crop_science'], $

  Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File)

; Create a zones object

zonesTask = ENVITask('AgCreateZones')

zonesTask.INPUT_RASTER = Raster

zonesTask.MINIMUM_AREA = 2023

zonesTask.NUMBER_OF_APPLICATION_CATEGORIES = 5

zonesTask.Execute

; Calculate zone metrics

metricsTask = ENVITask('AgCalculateZoneMetrics')

metricsTask.INPUT_RASTER = Raster

metricsTask.INPUT_ZONES = zonesTask.OUTPUT_ZONES

metricsTask.INPUT_ZONE_RASTER = zonesTask.OUTPUT_RASTER

metricsTask.Execute

outZones = metricsTask.OUTPUT_ZONES

; Print the properties of the output zones object

Print, outZones

Syntax

Result = ENVITask('AgCalculateZoneMetrics')

Input properties (Set, Get): INPUT_RASTER, INPUT_ZONE_RASTER, INPUT_ZONES, OUTPUT_ZONES_URI

Output properties (Get only): OUTPUT_ZONES

Properties marked as "Init" are applied only during the initial creation of the object. Properties marked as "Set" are those that you can set to specific values after the object has been created. 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_RASTER (required)

Specify a single-band raster from which zone metrics will be computed.

INPUT_ZONE_RASTER (optional)

Specify the zone classification raster that corresponds to the input zones. It allows metrics to be calculated faster for large images.

INPUT_ZONES (required)

Specify an input ENVIAgZones object.

OUTPUT_ZONES

This is a reference to the output ENVIAgZones object. In addition to the standard ENVIAgZone properties, the output object will contain the following attributes:

SOURCE_RASTER_NCOLUMNS: The number of columns in the source raster
SOURCE_RASTER_NROWS: The number of rows in the source raster
SOURCE_RASTER_SPATIALREF: The spatial reference of the source raster
ZONE_MAX: The maximum pixel value for each zone
ZONE_MEAN: The mean pixel value for each zone
ZONE_MIN: The minimum pixel value for each zone
ZONE_STDEV: The standard deviation pixel value for each zone

OUTPUT_ZONES_URI (optional)

Specify a string with the fully qualified filename and path of the output zones.

Version History

1.1	Introduced
1.1.1	Added INPUT_ZONE_RASTER property