Spatial correlation

Command line

The Spatial correlation operation be directly executed by typing one of the following expressions on the command line of the Main window:

  

OUTTABLE

=

TableSpatCorr(InputPointMap)

OUTTABLE

=

TableSpatCorr(InputPointMap, LagSpacing)

OUTTABLE

=

TableSpatCorr(InputPointMap, LagSpacing, Direction)

OUTTABLE

=

TableSpatCorr(InputPointMap, LagSpacing, Direction, Tolerance)

OUTTABLE

=

TableSpatCorr(InputPointMap, LagSpacing, Direction, Tolerance, Bandwidth)

OUTTABLE

=

TableSpatCorr(InputPointMap, LagSpacing, plane | sphere)

where:

OUTTABLE

is the name of your output spatial correlation table.

TableSpatCorr

is the command to start the Spatial correlation operation.

InputPointMap

is the name of your input point map (value map). When you want to use a Class or ID point map with an attribute table linked to the map, you can use: InputPointMap.ColumnName

LagSpacing

is an optional parameter to specify the length in meters for the linear distance intervals that should be used. When this parameter is not used, logarithmic distance intervals will be calculated.

Direction

To use the 'bidirectional' method: an optional parameter to specify an angle in degrees for the direction in which point pairs should be found. Direction 0� is North; direction 90� is East. The direction is a clockwise angle from the Y-axis. 0�  direction  90�.
When this parameter is not used your semi-variogram values will be 'omnidirectional'.

Tolerance

is an optional parameter to specify half of the opening angle in degrees with which point pairs in a certain direction should be found. 0� < tolerance 45�.
When a Direction is specified but the Tolerance is not specified, a Tolerance of 45� will be used (meaning that all points will be found).

Bandwidth

is an optional parameter to specify half of the maximum width in meters within which point pairs within a certain angle and in a certain direction should be found. By specifying a band width, you will limit the opening angle to a certain width; the opening width with which point pairs can be found in a certain direction will never be broader than twice the specified band width.
When this parameter is not specified, there is no limitation for the width of the opening angle.

plane | sphere

When using the 'omnidirectional' method: an optional parameter to calculate distances in a plane (plane), or on the sphere by using the projection of the coordinate system of the input point map (sphere).
If not specified, distances will be calculated in a plane.

When the first formula is used, only spatial autocorrelation and spatial variance are calculated, i.e. no semi-variogram values. Furthermore, instead of linear distance classes, you will obtain a number of logarithmic distance classes.

When the definition symbol = is used, a dependent output table is created; when the assignment symbol := is used, the dependency link is immediately broken after the output table has been calculated.

See also: