Pitney Bowes MapInfo Vertical Mapper - Manual (Page 121)

Chapter 7: Using Grids for Spatial Analysis
User Guide
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7. In the Grid Calculator – Save dialog box, do the following:
• In the Save the New Grid As box, type a file name for the new derived grid built from the
math expression.
• In the Description box, type a description of the new grid.
• From the Z-Unit Type list, choose a z-unit type. If the unit type is user-defined, you can type
a custom entry in the Enter User Defined Type box.
8. Click the OK button.
The new grid file appears in a Map window with a default colour palette applied.
Exploring the Calculator Dialog Box
The Calculator dialog box enables you to build mathematical expressions that modify or combine
grid files. The number and operator buttons in the Calculator function just like those on a scientific
calculator.
The window at the top of the dialog box lists all of the numeric grids currently open in the Grid
Manager. An alias name is assigned to each grid or value and is used to identify the item in the
Expression box.
One major advantage of using an alias instead of the actual grid file name is that the same
expression can be applied using different grids.
The New button Opens the Variable Editor and enables you to define a new numeric entry and an
alias for it. For example, a new value entry could be a numeric constant such as the value of
π to 12
decimal places of precision.