This task creates a 2D array of subrects based on the spatial extent of individual vector records. A subrect is a bounding box used to spatially subset a raster. The number of resulting subrects will be equal to the number of separate vector records.
It is part of a sequence for dicing rasters:
Consider using ENVIDiceRasterByVector to perform these steps in one task.
Example
e = ENVI()
File = Filepath('qb_boulder_msi', Subdir=['data'], $
Root_Dir=e.Root_Dir)
Raster = e.OpenRaster(File)
VectorFile = Filepath('qb_boulder_msi_vectors.shp', $
SUBDIRECTORY=['data'], ROOT_DIR=e.Root_Dir)
Vector = e.OpenVector(VectorFile)
Task = ENVITask('CreateSubrectsFromVector')
Task.INPUT_VECTOR = Vector
Task.INPUT_RASTER = Raster
Task.Execute
Subrects = Task.SUBRECTS
SubNames = Task.SUBRECT_NAMES
Help, Subrects
IDL prints:
SUBRECTS LONG =Array[4, 22]
This shows that 22 subrects were created with four coordinate points each. Now pass the subrects to the DiceRasterBySubrects task:
DiceTask = ENVITask('DiceRasterBySubrects')
DiceTask.INPUT_RASTER = Raster
DiceTask.SUBRECT_ARRAY = Subrects
DiceTask.SUBRECT_NAMES = SubNames
DiceTask.Execute
ExportTask = ENVITask('ExportRastersToDirectory')
ExportTask.INPUT_RASTER = DiceTask.OUTPUT_RASTER
ExportTask.OUTPUT_DIRECTORY = Filepath('', /TMP)
ExportTask.Execute
Syntax
Result = ENVITask('CreateSubrectsFromVector')
Input parameters (Set, Get): INPUT_RASTER, INPUT_VECTOR
Output parameters (Get only): SUBRECTS, SUBRECT_NAMES
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 the input raster.
INPUT_VECTOR (required)
Specify the input vector shapefile that will be used to create the subrects.
Output Parameters
SUBRECTS
This parameter contains an array of output subrects.
SUBRECT_NAMES
This parameter contains the names of each output subrect.
Methods
Execute
Parameter
ParameterNames
Properties
DESCRIPTION
DISPLAY_NAME
NAME
REVISION
TAGS
Version History
See Also
ENVITask, ENVITask::Parameter, ENVISubsetRaster, CreateSubrectsFromDistance Task, CreateSubrectsFromPixels Task, CreateSubrectsFromROI Task, CreateSubrectsFromTileCount Task, CreateSubrectsFromVector Task, DiceRasterByDistance Task, DiceRasterBySubrects Task, DiceRasterByPixel Task, DiceRasterByTileCount Task, ExportRastersToDirectory Task