All Cadcorp SIS API Methods

GetPrjScaleAtCentre Method

Description

Gets the scale at the centre of a named coordinate reference system.

Syntax

Visual Basic 
Public Function GetPrjScaleAtCentre( _
   ByVal prj As String _
) As Double

Parameters

prj
The coordinate reference system to query. This can be defined as:
  • OGC URNs (eg 'urn:ogc:def:crs:OGC:1.3:CRS84')
  • EPSG URNs (eg 'urn:ogc:def:crs:EPSG::27700')
  • EPSG code strings (eg 'EPSG:27700')
  • EPSG URLs (eg 'http://www.example.com/epsg#27700' or 'http://www.example.com/epsg.xml#27700')
  • EPSG codes as a simple string (eg '27700')
If blank, this will default to the current 'axes' CRS.

Return Type

The scale at the centre of a named coordinate reference system. This is necessary for interacting with the RenderTile method.

Remarks

Use this API if you want to calculate the RenderTile’s level parameter from map scale, or scale from level. You can also use it if you want to know the extent of the returned tile in coordinate reference system units. The calculation is slightly lengthy and must also take _OutputDPI& into account.

Available: GEO D OD OM SISpy

Group:

Example

sis.GetPrjScaleAtCentre ( "NAD27.Arizona East" )