RMOVERLAP

Description

RMOVERLAP removes any overlap areas from input polygons to make automatic mosaicking more efficient.

Parameters

rmoverlap(fili, dbiv, file, dbsl, filo, ftype, foptions, dbsn, dbsd, fldnme, prtord, lasc)

Name	Type	Caption	Length	Value range
FILI *	str	Input file name	1 -
DBIV *	List[int]	Input vector segment	1 - 1
FILE	str	Merged vector layer	0 -
DBSL	List[int]	Merged vector segment	0 - 1
FILO	str	Output file name	0 -
FTYPE *	str	Output file type	3 - 3	Default: PIX
FOPTIONS	str	Output file options	0 - 64
DBSN	str	Output segment name	0 - 8
DBSD	str	Output segment description	0 - 64
FLDNME	str	Attribute field name	0 -
PRTORD	str	Priority order	0 - 7	ASCEND, DESCEND Default: ASCEND
LASC	List[int]	Last segment created	0 - 1

* Required parameter

Parameter descriptions

FILI

Specifies the name of the input GDB-supported file (with full path) containing the vector segment defined by DBIV. Usually the file format is PCIDSK. The vector segment must be whole polygon segment.

DBIV

Specifies the segment number of the input cutline vector segment or layer. Its type must be whole polygon.

FILE

If this parameter is used, the polygons specified with FILI and DBIV are merged into a vector layer. The FILE parameter specifies the file that will contain this vector layer.

DBSL

Specifies the input segment of the merged polygon vector layer created when the FILE parameter is used.

FILO

Specifies the name of the file containing the output vector layer with all overlapping areas removed.

If this parameter is not specified, the output layer is created in the input file (FILI). If FILO specifies an existing file, a new layer is added; otherwise a new file is created.

FTYPE

Specifies the output file format type, represented by a three- or four-letter code. The format type must be a GDB-recognized file type.

The default value is PIX.

A full list of GDB-recognized file types and their codes is provided in the 'GDB file formats' section of the CATALYST Professional online Help.

FOPTIONS

Specifies the file creation options that are to be applied when creating the output file. These are specific to the file format; in each case, the default of no options is allowed. FOPTIONS can be used to specify the compression schemes, file format subtypes, and other information.

Different options are available for different file types (see the FTYPE parameter). The options are described in the 'GDB file formats' section of the CATALYST Professional online Help.

DBSN

Specifies a name (up to 8 characters) for the output vector segment.

DBSD

Describes (in up to 64 characters) the contents or origins of the output vector segment.

FLDNME

Specifies the name of the attribute field for each shape in the cutline layer. The value of the field specified indicates from which polygon the overlap area should be removed. If the FLDNME (Field Name) parameter is specified, the PRTORD (Priority Order) parameter is based on the field value of each polygon; otherwise, priority is based on each polygon's shape ID.

The field type can be integer, float, double, or string.

PRTORD

Specifies the priority order of processing for the field value or shape ID indicated by the FLDNME (Field Name) parameter. The two valid values for this parameter are ASCEND or DESCEND. DESCEND is the default. When this parameter is set to ASCEND, the higher value or shape ID is given a lower priority. When it is set to DESCEND, the higher value or shape ID is given a higher priority. The polygon with a higher priority will go on top.

LASC

The segment number for the output vector is saved in the output parameter LASC when RMOVERLAP exits.

Details

RMOVERLAP is designed to improve the efficiency of automatic mosaicking by removing any overlapped cutline sections from polygons in a vector layer before the automatic mosaicking process begins.

The input vector segment must be a whole polygon layer. If a new polygon segment is provided (FILE and DBSL), the input polygon segment must not have overlaps and must have the same attribute schema as the polygon vector segment specified by FILI and DBIV.

If a polygon becomes separated into parts after removing the overlap, all polygons are combined into one shape using rings. If one polygon is completely covered by another, it becomes a shape without vertices. If one polyogn is completely inside another, the larger polygon will have a hole.

All attributes remain unchanged in the output segment.

The segment number of the resulting vector data is output to the LASC parameter before RMOVERLAP exits.

Example

You want to cut polygons to remove any overlap areas from mycutlines.pix file . The cutlines are located in vector segment 2. The results are transferred to vector segment 2 in a new file called corcutlines.pix.

from pci.rmoverlap import rmoverlap

fili = 'mycutlines1.pix'
dbiv = [2]         #Vector segment
file = ''
dbsl = []
filo = 'corcutlines.pix'
ftype = ''
foptions = ''

dbsn = ''           #Use input segment's name
dbsd = ''           #Use input segment's descriptor
fldnme = ''         #Use the default ATTRIBUTE field
prtord = ''         #Priority order - use ASCEND by default
lasc = []

rmoverlap(fili, dbiv, file, dbsl, filo, ftype, foptions, dbsn,\
dbsd, fldnme, prtord, lasc)