SMCHAIKEN

Description

SMCHAIKEN performs vector smoothing using the Chaiken algorithm. The Chaiken algorithm differs from the McMaster and Boyle vector smoothing algorithms by adding new vertices when performing the smoothing operation.

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
DISTTOL*	Float	Distance tolerance	1 - 1
TOLVALUE	Float	Tolerance value	0 - 1	0 - Default: 0.5
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.

DISTTOL

Specifies the distance tolerance value. This value cannot be zero.

Setting the distance close to the average length of the vectors provides the best results. If the tolerance value is not properly specified, it can add a large number of vertices to the output vector layer.

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.

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

SMCHAIKEN performs vector smoothing using the Chaiken algorithm. The Chaiken algorithm differs from the McMaster and Boyle vector smoothing algorithms by adding new vertices when performing the smoothing operation.

The Chaiken algorithm is not suitable for smoothing vectors produced by raster-to-vector conversion programs (stepped linework); the McMaster algorithm works best on these vectors. SMCHAIKEN is more suitable for digitized vectors where the distance between vertices is consistent.

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

Example

Apply Chaiken smoothing to vector layer 25 from "irvine.pix" with a TOLVALUE of 0.5 and a distance tolerance of 10. The smoothed vector will be stored in a new file named "oirvine.pix".

EASI>FILI     = "irvine.pix"
EASI>FILO     = "oirvine.pix"
EASI>DBVS     = 25               ! smoothing vector 25 from irvine.pix
EASI>DISTTOL  = 10               ! use value 10 for distance tolerance
EASI>TOLVALUE =                  ! defaults to 0.5
EASI>DBSN     =                  ! defaults to Vectors
EASI>DBSD     =                  ! will be taken from DBVS
EASI>REPORT   =                  ! defaults to TERM
EASI>MONITOR  =                  ! defaults to ON

EASI>run smchaiken