Occurrence
Some examples of use:
- Updating regional RAB drillhole collar locations with accurate RL's from a topographic grid surface provided by a geophysical contractor
- Assigning geological, regolith or tenement polygons mean or maximum copper assay vlaues from an underlying gridded geochemical surface (created using IDW interpolation) as part of prospectivity mapping
Solution
1/. Ensure that the vector data table has the necessary numeric field/s to capture grid data into, using the TABLE>Maintenance>Table>Modify Structure tool. For example, if populating a drillhole collar table with RL values from a DEM grid, create an 'RL' or 'Elevation' field with a Float type.
2/. Open into a map window both the vector table to update, and the source grid.
3/. Select the vector data to update, using either a graphical selection tool (to select a subset of the vector data), or right click on the layer and Select All menu option in the Explorer, window or a Query.
4/. If it is displayed as a legacy grid, Select the SURFACES>Utilities>Assign Values option. Or if displayed as a RASTER layer,
MapInfo Pro Raster provides this functionality as 3 enhanced tools specific to the vector type under RASTER>Operations:
- Point Inspect
- Line Stats
- Region Stats
5/. If updating point data (a one to one relationship), select the output field.
6/. If updating polygon or polyline data (i.e. a many to one relationship: for example, populating tenement polygons with the average values from a regional copper soil sampling grid), the dialog will prompt for destination fields for Average, Minimum and Maximum values. The user can specify one or multiple of these output calculations.
7/. Press OK to run update. The results can be viewed by opening a browser window of the vector table, and scrolling to the destination field/s.
8/. Select File>Save Table and select the updated vector table to make these changes permanent.