Pitney Bowes MapInfo Vertical Mapper - Manual (Page 163)

Chapter 9: Data Analysis
User Guide
161
Exploring the Variogram Dialog Box
This dialog box is available from the Vertical Mapper, Data Analysis, Semi-variogram Analysis
command and from the Variogram Builder button in the Kriging Interpolation dialog box. The top
portion of the dialog box displays the experimental semivariogram of the data along with settings
that control the directional calculations. The bottom portion of the dialog box contains settings that
tune the model. By default, a “best-fit” model is automatically calculated, and you can further modify
it manually.
The Experimental section contains the following options:
• The Directions box enables you to specify the number of directions that will be analyzed. The
default value is two with a minimum of one and a maximum of six.
• The Active box enables you to specify which direction is currently being modified. The active
direction is shown by a solid fill colour in the circle view diagram.
• The Angle box enables you to specify the angle in degrees with respect to true north in which
the active direction is facing.
• The Tolerance box enables you to set the interval in degrees on either side of the angle setting
within which points will be considered.
• The Lag Distance box enables you to specify the distance at which sample pairs will be
analyzed for variance. This value increases until every point in the data has been examined. The
default value is the mean distance between points for the aggregated data.
The Circle View diagram represents each of the specified directions and their respective tolerances.
The solid coloured region represents the active direction for which any changes to the angle or
tolerance settings will be applied.