All Cadcorp SIS API Methods

CreateGeodeticBuffer Method

Description

Creates a 'geodetic' buffer around items in a named list.

Syntax

Public Function CreateGeodeticBuffer( _
   ByVal list As String, _
   ByVal datum As String, _
   ByVal distance As Double, _
   ByVal nPoints As Long _
) As Integer

Parameters

list

The named list to be scanned.

 

datum

The named datum to be used, e.g. WGS 84.

 

distance

The size of the buffer.

 

nPoints

The number of points to be used when creating the buffer (see Remarks).

Remarks

• SIS builds the buffer by constructing a temporary set of circles along the route of the buffer. The distance argument must be a minimum of 1000m, below this the geodetic nature of the buffer is negligible.
• The nPoints argument determines how many points are used to construct each circle, thus defining the accuracy of the resulting buffer.
• The minimum value for the nPoints argument is 4, anything less than a square is not viable.

Available: GEO  OD SISpy

Group:

• Drawing Methods

Example

sis.CreateGeodeticBuffer ("Points", "WGS84", 1000.0,50)

Creates a geodetic buffer on all items in the named list called Points. The datum used is WGS84, but the buffer created is 1000m in size.