Paramfile is a text file with user defined parameters. Lines in paramfile normally have the format: ParameterName: value .... Lines that start with # are treated as comments. When packages load, they scan the parameter file for user information, such as data directories and desired features. Lines of no interest to the package (including erroneous ones) are skipped.
If the paramfile argument is absent, visky will try to get the parameter file name from the VISKY_PARAMS environment variable. This is useful for developers who want to source the script files from the Tcl command line (i.e. with wish).
File paramfile is an sample parameter file and starting point. Note that case is ignored when parsing the parameter name. The rest of the line is probably case sensitive, especially if it has file names. A parameter value with a $ prefix is substituted for the given variable value in the Tcl script. This is particularly useful for requesting environment variables. For example, a file in the home directory named foo would be represented in the parameter file as $env(HOME)/foo.
The parameter file MUST contain a line of form:
MapData: dirwhere dir is a directory containing one of the map data sets described on the mapdata page. The rest of the parameter file will vary according to which packages are wanted and what they require.
Once started, visky will load its geographic data and display it on a map. The viewed region can be adjusted by dragging. The main menu provides general controls and a place for packages to add their menus. A text display below the map provides information about the cursor as it moves around, such as its latitude-longitude or the name of the nearest town.
Double clicking the right mouse button sets a small + marker. As the cursor moves, the text display below the map shows the bearing and range from the + to the cursor. This is useful for general measurements.
Sometimes several packages have a binding for mouse double-clicks. When this happens, and row of buttons below the map window controls which binding is in effect.
As it runs, visky occasionally stores state information in files it creates in directories $HOME/.visky and $HOME/.mapdata. The exact files and their contents depend on which packages are loaded and what the user does during the session. Visky reads these files during startup to restore some aspects of the previous run, such as the map center, scale , colors and initial search directories for file open dialog boxes. Deleting these files or directories restores visky's default behavior. The web pages for the individual packages have more details on the files in $HOME/.visky and $HOME/.mapdata.
The Widget menu is always present with the following items:
Packages can be loaded while the program is running by selecting them from the Widget->Packages cascade menu. If a package is already loaded, it is listed on the cascade menu in parentheses, e.g. (Hurricanes) in which case selecting it UNLOADS the package. This can be useful if memory is short, or if there was a mistake in the parameter file and the package must be reloaded.
Current packages: