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Product: MapInfo
Version: 4.x\5.x\6.x
Platform: Not Platform Related
Category: Geocoding & Create Points
Summary:
Creating points.
Question:
How to create points from a table with
columns containing longitude and latitude coordinates.
Answer:
The following process will show how to create
points from a table that has columns which contain X and Y coordinates. It is
helpful to make any changes on a copy of the table. It may be necessary to use
the original data at a later time.
1. Open the table through File>Open Table
to be used to create points.
2. Select Table>Maintenance>Table
Structure <tablename> and confirm that the columns that hold the
coordinates have the data type of decimal or float.
HINT: If it is known approximately where the
points will be located, open a map that contains that area. When double
clicking on the map, a Region Object box will appear. This box will contain
information about the area that was clicked on. For example, if the points
will be located in the state of Kansas, open the states map and click on the
state of Kansas. The following dialog box will appear:
The information returned from this dialog
shows that the Y values for
Kansas should be positive numbers between
36.99 and 40.00, and the
X values should be between negative 102 and
negative 94.6.
3. Examine the browser for the data to
determine which columns contain the latitude (Y) and the longitude (X)
coordinates.
4. Determine the multiplier for the X and Y
columns. For example, if the points are expected to fall in Kansas, the X
value is expected to be between negative 102 and negative 94. In the above
browser, the data for X (Longitude) is close to positive 98. The multiplier
should be negative 1 to create the points correctly. The Y (Latitude) values
are in the correct range and require a multiplier of positive 1 (i.e. +1 will
not change the value).
5. Open the Create Points dialog box
(Table>Create Points), and insert the proper columns in the Get X
Coordinates, Get Y Coordinates boxes and the correct multipliers in the
Multiply X and Multiply Y boxes.
At this point, click OK and the points should
be created for the table. They can be displayed
by adding the layer to current mapper
(Map>Layer Control>Add) or create a new window through
Window>New Mapper Window.
Important Notes (Trouble Shooting):
Create Points option grayed out:
Confirm
that there are at least two NUMERIC fields in the table. MapInfo can only
create points on coordinates found in numeric fields.
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