AgCalculateAndRasterizeZoneMetrics Task

This task calculates statistics from a single-band raster and an associated ENVIAgZones object. It creates a classification raster showing the relative values of zones or a grayscale raster showing actual statistical values of zones.

AgCalculateAndRasterizeZoneMetrics Task is a metatask that automatically runs the following tasks:

This task requires a separate license for the ENVI Crop Science Module; contact your sales representative for more information.

Example

This example:

Uses a DEM as the basis for splitting a field into five management zones.
Runs AgCreateZones Task to create the zones.
Runs AgCalculateAndRasterizeZoneMetrics Task and displays a grayscale image of mean elevation values for each zone.

; Start the application

e = ENVI()

; 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 and rasterize zone metrics

Task = ENVITask('AgCalculateAndRasterizeZoneMetrics')

Task.INPUT_RASTER = Raster

Task.INPUT_ZONES = zonesTask.OUTPUT_ZONES

Task.INPUT_ZONE_RASTER = zonesTask.OUTPUT_RASTER

Task.Execute

; Get the collection of objects currently in the Data Manager

DataColl = e.Data

; Add the output to the data collection

DataColl.Add, Task.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(Task.OUTPUT_RASTER)

Syntax

Result = ENVITask('AgCalculateAndRasterizeZoneMetrics')

Input parameters (Set, Get): INPUT_RASTER, INPUT_ZONE_RASTER, INPUT_ZONES, OUTPUT_METRIC, OUTPUT_RASTER_URI, OUTPUT_ZONES_URI

Output parameters (Get only): OUTPUT_RASTER, OUTPUT_ZONES

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_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_METRIC (optional)

Specify one of the following strings, indicating the metric that the output raster will be based on.

Zone Mean (default)
Zone Maximum
Zone Minimum
Zone Standard Deviation

OUTPUT_RASTER_URI (optional)

Specify a string with the fully qualified filename and path of the associated OUTPUT_RASTER.

If you do not specify this parameter, or set it to an exclamation symbol (!), ENVI creates a temporary file.
If you set it to the hash symbol (#), ENVI creates a file in the temporary directory, but this file will not be deleted when ENVI closes.