ENVIROI::AddGeometry

The AddGeometry method adds polygons, polylines, or points to an ROI.

Example

; Launch the application

e = ENVI()

 

; Open the input file

file = Filepath('qb_boulder_msi', ROOT_DIR=e.Root_Dir, $

SUBDIRECTORY=['data'])

raster = e.OpenRaster(file)

view = e.GetView()

layer = view.CreateLayer(raster)

 

; Define a new ROI with a polygon and display it

roi = EnviRoi(NAME='Tennis Court', COLOR='Green')

data = [[480872.7214d, 4428333.0664d], $

       [480908.2576d, 4428333.0664d], $

       [480907.5742d, 4428265.4108d], $

       [480873.3289d, 4428265.7720d], $

       [480872.7214d, 4428333.0664d]]

roi.AddGeometry, data, coord_sys=raster.SpatialRef.Coord_Sys_Str, /POLYGON

roiLayer = layer.AddRoi(roi)

Syntax

ENVIROI.AddGeometry, Data [, Keywords=value]

Arguments

Data

A 2xn array that defines the vertex data, stored as double-precision floating point. Data can represent UTM map coordinates or Geographic Lat/Lon coordinates. X is easting or longitude, and Y is northing or latitude.

Keywords

COORD_SYS

Set the ENVIRaster reference that establishes the coordinate system reference for the ROI locations contained in the data. This keyword is not required; however, if it is not specified, ENVI will be unable to reproject the ROI geometry correctly. COORD_SYS supports only standard projections (Geographic Lat/Lon and UTM).

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.

POINT

Set this keyword to indicate that the data arrays define a set of individual vertices.

POLYGON

Set this keyword to indicate that the data arrays define a closed polygon. The first and last data point in data points must be the same. When you set the POLYGON keyword, you must specify at least three non-collinear vertices.

POLYLINE

Set this keyword to indicate that the data array define a polyline. When you set the POLYLINE keyword, you must specify at least two unique vertices.

Version History

ENVI 5.1

Introduced

API Version

4.2

See Also

ENVIROI, ENVIRaster, ENVIROI::ClearGeometry