Name
geo – Geographical coordinates handling
Syntax - Converting between coordinate systems
geo [cvt] [xy] [lla]
Syntax - Displaying geographical lines
geo dra [lon] [lat] [cut] [fra] [col] [set]
Syntax - Annotate geographical axes
geo ann
Syntax - Setting options for geographical coordinates
geo set
Syntax - Calculate distances between the points in a dataset
geo line point
Description
Handling and display of geographical coordinates.
The geo command has a syntax for coordinate conversion and display of geographical coordinates. The geo command is applied for instance in the menu script geodesy.tcl that comes up from Tools > Geographical Management . In order to learn the command and practical use one can look into the script. Look in the Geocap installation directory under the Geodesy module.
Geodesywidget
The geo command uses coordinate information from the menu. This is handled through a special widget called geodesywidget which is designed to be used in tcl scripts. One can think of geodesywidget as a complex tcl variable which contains the coordinate and datum information seen in the panel.
The conversion menu in Geodesy.tcl is organized in two parts: 1) upper and 2) lower . The conversion is from upper to lower or the other way. Active data is always part of the conversion as the input dataset.
Due to the geodesywidget the script code for conversion and display of geographical coordinates is relatively small.
Below is shown how the tcl code reads the upper and lower geodesywidget into two global variables called cu and cl . Those variables can be used in conversion control later on.
# Setting upper and lower geodesywidget into a tcl variables set ::cu [geodesywidget] set ::cl [geodesywidget]
The statements above is written into the menu part where upper and lower is coded. A change in a geodesywidget will then immediately update the global variables.
Arguments
geo cvt [low] coord
geo xy xcoordinate ycoordinate
geo xy | lla coord
geo dra [lon | lat] [inc] [cut] [fra] [col]
geo ann updown annofreq
To see how to draw geographical annotation look into the procedure GcGeodesy::annotateGeoGrid in geodesy.tcl .
geo set [oldgeo | sticky | geolev]
Display examples of map with geographical coordinates
The first example is from the workflow Seismic and reservoir models - Course B1.
Cartographical display from course workflow
The next examples are nice displays with cartographic standard.
Geographical coordinates from Atlantis demo project
Cartographical display in Polar Stereographic projection