ENVIDataCollection::Count

The Count method returns the number of objects open in the Data Manager.

Example

; Start the application

e = ENVI()

 

; Open a raster file

File = Filepath('qb_boulder_msi', Root_Dir=e.Root_Dir, $

Subdir = ['data'])

Raster = e.OpenRaster(File)

 

; Open a vector file

Vect = Filepath('qb_boulder_msi_vectors.shp', $

   Root_Dir=e.Root_Dir, Subdir = ['data'])

Vector = e.OpenVector(Vect)

 

; Get the collection of data objects currently available in the Data Manager

DataColl = e.Data

 

; Retrieve the number of items in the data collection

Num = DataColl.Count()

Print, Num

Syntax

Result = ENVIDataCollection.Count([, Keywords=value])

Return Value

This method returns the number of items in the data collection.

Keywords

ANNOTATION (optional)

Set this keyword to return only a list of ENVIAnnotationSet objects.

ERROR (optional)

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

RASTER (optional)

Set this keyword to return only a list of ENVIRaster objects.

ROI (optional)

Set this keyword to return only a list of ENVIROI objects.

SERIES_RASTER (optional)

Set this keyword to return only a list of ENVIRasterSeries objects.

VECTOR (optional)

Set this keyword to return only a list of ENVIVector objects.

Version History

ENVI 5.1	Introduced
ENVI 5.6.1	Added ANNOTATION and ROI keywords

API Version

4.2

See Also

ENVIDataCollection