SMBOYLE

Description

SMBOYLE performs vector smoothing using the Boyle algorithm. The user defines the number of vertices to look ahead before applying the specified tolerance value to determine the new,"smoothed" vertex.

Parameters

Name	Type	Length	Value range
InputA: Input vector segment*	Vector port	1 - 1
OutputA: Output vector segment*	Vector port	1 - 1
Tolerance Value	Float	0 - 1	0 - Default: 0.5
Vertex Look Ahead	Integer	0 - 1	1 - Default: 1
Report	String	0 - 192	See parameter description

* Required parameter

Parameter descriptions

InputA: Input vector segment

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

OutputA: Output vector segment

Specifies the vector segment to receive the smoothed output vector layer.

Tolerance Value

Specifies the tolerance value, which is the proportion of distance to place the new vertex between the start vertex and the look ahead vertex.

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

Vertex Look Ahead

Specifies the vertex look ahead value, the number of vertices to "look ahead" each time, before it calculates a new vertex for the resultant smoothed vector.

The look ahead value must be greater than or equal to 1.

Report

Specifies where to direct the generated report.

Available options are:

• LOG: generates a report on the terminal (default)
• <modulename.RPT>: appends a report to the module's RPT file
• DISK: generates a report on file "IMPRPT.LST"

Details

The SMBOYLE algorithm produces better results from digitized vectors. For vectors produced by raster-to-vector conversion programs (stepped linework), the "look ahead" value has a large influence; SMMCMASTER is more suited to these vectors. SMBOYLE is not suitable for vectors containing few vertices (the result of raster-to-vector conversion programs can often create these), including small, closed shapes.

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