Datamine Discover KB - Object Editing

How do I calculate the bearing of a line?

kbadmin — Mon, 26 Feb 2024 03:31:28 GMT

Occurrence

The MapInfo Ruler tool does not give a bearing angle!

How do I calculate the bearing of a line, or between two points?

Solution

To calculate a bearing interactively with a ruler tool, use Discover's

QUERY>Map Object>Location Info

Or to calculate a selected lines bearing and saved in as a attribute use -

QUERY>Map Object>Line Orientation

These 2 Discover tools both create a line Bearing, clockwise from North.

If you have MapInfo MapCAD Loaded, this adds a tool under -

SPATIAL>Calculate>Calculate Direction

This is incorrect. It calculates a mathematical standard cartesian angle, which is counter clockwise from the right hand direction (East).

To convert this into a GIS bearing, which is clockwise from North (top of map) you need to apply the following -

degResult = 90.0 - mathBasedDeg;

if (degResult < 0)

degResult += 360;

if (degResult > 360)

degResult -= 360;

I am planning a regional exploration work program. What tools are available in Discover?

Josh Knight — Wed, 04 May 2022 03:05:48 GMT

Occurrence

How do I:

A. Add coordinates to a series of discrete point locations such as proposed regional RAB/aircore drill targets, and then add an incrementing identifier (e.g. HoleID) to each location?

B. Convert a series of proposed regional traverse lines/polylines into grid pegs/sample locations at a fixed spacing, each with coordinates and unique ID's?

C. Create a series of parallel traverse/sample line (i.e. a local grid), with pegs/point locations at fixed spacings, each with both local and real world coordinates, as well as unique ID's?

Solution

A. Add coordinates to a series of discrete point locations such as proposed regional RAB/aircore drill targets, and then add an incrementing identifier (e.g. HoleID) to each location?

1/. If a series of target locations have been added to say the cosmetic layer as points (e.g. the intersection of regional lineaments/faults with prospective stratigraphy), save these point objects to a new table (Map>Save Cosmetic Objects).

2/. Use Discover's Discover>Projection>Update Coordinates tool to create a new Easting/X and Northing/Y field to this table, and automatically populate these fields with the appropriate values. Note that by default the coordinates will ...

How do I clip my data to a polygon region?

kbadmin — Tue, 01 Sep 2020 23:36:15 GMT

Discover provides a number of tools to clip your map data to a area within a selected polygon -

1) Vector layers - QUERY>Map Object>Vector Clip
2) Images - IMAGES>Images Tools>Clip Image
3) Surface Grids - SURFACES>Utilities>Clip

Some raster images and raster grids may also be clipped with RASTER>Operations>Clip

How do I clip my data down to a selected polygon or region boundary?

Josh Knight — Mon, 12 Nov 2018 00:04:25 GMT

Discover provides a number of tools that allow you to clip or cut your datasets down to selected regions/areas. An example would be to provide subsetted datasets to government organisations for lease relinquishment reports, or to a joint venture partner.

The tools are data type specific, i.e. vector, image or grid data:

Vector Data

(e.g. point, polygon or polyline data, such as soil sample or drillhole point locations, surface geology regions, traverse lines and track polyline data)

Use Discover's QUERY>Map Object>Vector Clip tool. This requires the user to select one or more bounding regions/polygons (e.g. the sub-blocks to be relinquished) before running the tool.

Raster Data (e.g. airphotos, landsat imagery)

The Images menu has a Clip Image tool. This provides 2 methods for defining the clip region/area:

1. Select one or more bounding regions/polygons (e.g. the sub-blocks to be relinquished) before running the tool. Within the tool, enable the 'Clip outside polygon' option, and ensure that the 'Polygon Table * Selection *' is selected

2. Within the tool, select the table containing the polygonal areas to clip the image to. All polygons in the specified table or selection will be used for clipping.

Gridded Surfaces

(e. ...

Polybuilder crashes on a particular file

kbadmin — Mon, 14 May 2018 03:15:52 GMT

Occurrence

A particular file is crashing Polybuilder, both in the 32bit MapInfo 15.0 version, and the reintroduced back in Discover 2017 64bit,

Solution

This was due to a low level .MAP file format (where MapInfo stores vectors), and is resolved in Discover 2017 Update or later.

To workaround in previous version you need to open a Mapbasic window and enter this command, then press Return to execute it -

Commit table Geology as "C:\Geology_new.tab" Blocksize 512

Where Geology is the layer name of your existing file, and a new tab file to save it to.

Open the new tab file and it should work fine in Polybuilder.