Occurrence
Sometimes line or polygon data is received or collected as a file of discrete points, and needs to be
converted. Examples include:
- viewing the flight lines from an airborne geophysical survey
- creating traverse lines from soil or ground magnetics sample points
- displaying a route path from a series of locations collected with a GPS
- converting lithological boundaries mapped with a GPS into polygons
Solution
Discover > Table Utilities > Build Objects from Table
This utility requires each line / polygon to have a unique identifier or attribute. For instance, polyline
data may have a line number (Line 58A) or consant local grid northing value (e.g. 5500N), whilst
regions might have an appropriate attribute (Basalt12).
Assuming your data is in arranged with fields of say Easting, Northing, data_value (if appropriate
e.g. TMI or gravity reading) and Line number, choose the 'Column Delimited x.y Polylines (from
table) option' from the next dialog box. Check the Convert closed polylines to regions option
if applicable, and select OK.
In the following Import Polylines dialog, choose your point table and Easting and Northing fields and
assign a Projection. In the Object Delimiter section at the bottom of this dialog, select the Unique
Attribute option and use the 'in column' drop-down window to choose your line number field.
Press OK, create a file name for the new polyline table to be created, and press Save.
You will need to add the newly created polyline table to your existing map (it will not auto-appear).
