Pitney Bowes MapInfo Vertical Mapper - Manual (Page 155)

Chapter 8: Using the Grid Tools
User Guide
153
The Spliceable Grids list displays all grid files open in the Grid Manager that can be successfully
spliced with the reference grid.
This list is restricted to those grids that are the same grid type (numeric or classified), the same
projection, and the same z-units as the reference grid. There are no restrictions placed upon the cell
size of the input grids. The resulting grid will always have the same cell size as the reference grid.
The Add button enters the grid highlighted in the Spliceable Grids list in the Merge Process list. If
you have a number of grids to enter, you can select them using the CTRL key and then use the Add
All button to add all the selected grids to the Spliceable Grids list.
The Stamp and Merge buttons enable you to specify what type of splicing will be performed. Only
one of these processes can be performed at a time.
The Stamp button enables you to stamp two or more grids.
You cannot choose which mathematical calculation will be performed on the overlapping regions.
Grid values in the overlapping regions will be determined by the order in which grids are listed in the
Merge Process list.
The Merge button enables you to merge two or more grids.
You must specify the mathematical operation that will be performed on the grid cells contained in the
overlapping regions of the input grids. Choose one of the following options from the list: Average,
Minimum, Maximum, Median, or Average (Min, Max) (average of the minimum and maximum
values). These options are only available for splicing numeric grids and are applied to all grids in the
splicing process. It is not possible to use different operations on different grids in the same splicing
operation.
The Merge Process list displays all the grid files that will be used in the splicing operation, and the
reference grid will always be listed first.
A message will appear above the window reminding you what splicing process is chosen and
displaying a brief description of how the grids will be processed. The order in which the grids are
entered is only important when a Stamp is specified. The reference grid is stamped on the results
grid and the results grid is stamped on the third grid. The reference grid is always the top grid in the
Merge Process list. This process is repeated for each of the grids listed. The order in which the grids
are listed can be altered by choosing a grid and then dragging it to a different position in the list.
The Remove and Remove All buttons enable you to remove the highlighted grid or all the grids in
the Merge Process list. The reference grid will always remain in the window.
The File name box enables you to enter a unique file name for the spliced grid.
Trimming a Grid
The outer margin of any grid file can be trimmed using a predefined polygon created in a Map
window. This tool is particularly useful for trimming grid files to a standard map neatline. Only one
grid file can be trimmed at a time.
1. Create the trim region using the MapInfo Professional Polygon tool on an editable layer in a Map
window or choose the trim region from an open map file. If the region is not already a polygon,