SMMCMASTER

Description

SMMCMASTER performs vector smoothing using the McMaster algorithm. It selects first five vertices and calculates their average to find the new, "smoothed" vertex. SMMCMASTER may also be used with vectors containing less than five vertices.

Parameters

Name	Type	Caption	Length	Value range
FILI*	String	Input file name	1 - 192
FILO	String	Output file name	0 - 192
DBVS*	Integer	Input vector segment	1 - 1
TOLVALUE	Float	Tolerance value	0 - 1	Default: 0.5
SLIDEAVG	String	Use sliding average	0 - 5	TRUE | FALSE Default: FALSE
DBSN	String	Output segment name	0 - 8	Default: Vectors
DBSD	String	Output segment description	0 - 64
REPORT	String	Report mode	0 - 192	Quick links
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILI

Specifies the name of the PCIDSK image file containing the input arc layer to be smoothed.

FILO

Specifies the name of the PCIDSK image file to receive the smoothed output vector layer.

If FILO is not specified, FILI is used for the smoothed vector. If FILO is specified but does not exist, a new file is created.

DBVS

Specifies the vector segment containing the input arc layer to be smoothed.

TOLVALUE

Specifies the tolerance value. This value must be greater than zero and smaller than one. The larger the tolerance value, the more pronounced the smoothing effect.

SLIDEAVG

Specifies whether sliding average is to be used. Sliding average brings the smoothed vertex closer to the original line. The slide averaging has less affect the closer the tolerance value is to zero. The default value is FALSE (unchecked).

DBSN

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

DBSD

Describes (in up to 64 characters) the contents or origins of the new vector data.

REPORT

Specifies where to direct the generated report.

Available options are:

• TERM: generates a report on the terminal (default)
• DISK: generates a report on file "IMPRPT.LST"
• OFF: turns off report generation
• <filename>: appends a report to the specified file

MONITOR

The program progress can be monitored by printing the percentage of processing completed. A system parameter, MONITOR, controls this activity.

Available options are:

• ON: Turns the monitor ON (default)
• OFF: Turns the monitor OFF (recommended if running in batch or background mode)

Details

SMMCMASTER performs vector smoothing using the McMaster algorithm. It selects first five vertices and calculates their average to find the new, "smoothed" vertex. SMMCMASTER may also be used with vectors containing less than five vertices.

This algorithm works well for stepped linework vectors produced by raster-to-vector conversion routines, or those produced through digitizing.

SMMCMASTER does not alter the start and end vertices of a vector.

Example

Apply McMaster vector smoothing to layer 25 from "irvine.pix" with a TOLVALUE of 0.5 and no sliding average option. The smoothed vector will be stored in a new file named "oirvine.pix".

EASI>FILI     = "irvine.pix"
EASI>FILO     = "oirvine.pix"
EASI>DBVS     = 25
EASI>TOLVALUE =                  ! defaults to 0.5
EASI>SLIDEAVG =                  ! defaults to FALSE
EASI>DBSN     =                  ! Defaults to Vectors
EASI>DBSD     =                  ! will be taken from DBVS
EASI>REPORT   =                  ! defaults to TERM
EASI>MONITOR  =                  ! defaults to ON

EASI>run SMMCMASTERd