ENVIGCPSet::Count

The Count method counts the number of ground control points (GCPs) in an ENVIGCPSet object. Issuing a PRINT statement on the object also prints the total number of GCPs.

Example

; Start the application

e = ENVI()

; Open an existing GCP file

GCPFile = Dialog_Pickfile(TITLE='Select an ENVI .pts file')

GCPs = ENVIGCPSet(GCPFile)

Print, GCPs

; Count the number of GCPs

GCPCount = GCPs.Count()

Print, GCPCount

Syntax

Result = ENVIGCPSet.Count()

Return Value

This method returns the number of GCPs in an ENVIGCPSet object.

Arguments

None

Keywords

ERROR

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.

Version History

ENVI 5.1

Introduced

API Version

4.2