vmap0ui
UI for selecting data from Vector Map Level 0
Description
vmap0ui(dirname) launches a graphical user
interface for interactively selecting and importing data from a Vector
Map Level 0 (VMAP0) data base. dirname is a character
vector that specifies the folder containing the data base. For more
on using vmap0ui, click the Help button
after the interface appears.
vmap0ui(devicename) or vmap0ui
devicename uses the logical device (volume) name specified
in the character vector devicename to locate CD-ROM
drive containing the VMAP0 CD-ROM. Under the Windows® operating
system it could be 'F:', 'G:',
or some other letter. Under Macintosh OS X it should be '/Volumes/VMAP'.
Under other UNIX® systems it could be '/cdrom/'.
vmap0ui can be used on Windows without
any arguments. In this case it attempts to automatically detect a
drive containing a VMAP0 CD-ROM. If vmap0ui fails
to locate the CD-ROM device, then specify it explicitly.
Controls
The vmap0ui screen lets you read data from
the Vector Map Level 0 (VMAP0). The VMAP0 is the most detailed world
map database available to the public.
You use the list to select the type of data and the map to select the region of interest. When you click the Get button, data is extracted and displayed on the map. Use the Save button to save the data in a MAT-file or to the base workspace for later display. The Close button closes the window.
The Map
The Map controls the geographic
extent of the data to be extracted. vmap0ui extracts
data for areas currently visible on the map. Use the mouse to zoom
in or out to the area of interest. Type help zoom for
more on zooming.
The VMAP0 divides the world into tiles of about 5–by–5 degrees. When extracting, data is returned for all visible tiles, including those parts of the tile that are outside the current view. The map shows the VMAP0 tiles in light yellow with light gray edges. The data density is high, so extracting data for a large number of tiles can take much time and memory. A count of the number of visible tiles is above the map.
The List
The List controls the type
of data to be extracted. The tree structure of the list reflects the
structure of the VMAP0 database. Upon starting vmap0ui,
the list shows the major categories of VMAP data, called themes. Themes
are subdivided into features, which consist of data of common graphic
types (patch, line, point, or text) or cultural types (airport, roads,
railroads). Double-click a theme to see the associated features. Features
can have properties and values, for example, a railroad tracks property,
with values single or multiple. Double-click a feature to see the
associated properties and values. Double-clicking an open theme or
feature closes it. When a theme is selected, vmap0ui gets
all the associated features. When a feature is selected, vmap0ui gets
all of that feature's data. When properties and values are selected, vmap0ui gets
the data for any of the properties and values that match (that is,
the union operation).
The Get Button
The Get button reads the currently selected VMAP0 data and displays it on the map. Use the Cancel button on the progress bar to interrupt the process. For a quicker response, press the standard interrupt key combination for your platform.
The Clear Button
The Clear button removes any previously read data from the map.
The Save Button
The Save button saves the currently displayed VMAP0 data to a MAT-file or the base workspace. If you choose to save to a file, you are prompted for a file name and location. If you choose to save to the base workspace, you are notified of the variable names that will be overwritten.
Data are returned as Mapping Toolbox™ display structures
with variable names based on theme and feature names. You can update
vector display structures to geographic data structures. For information
about display structure format, see Version 1 Display Structures in the reference page
for displaym. The updategeostruct function performs such conversions.
Use load and displaym to
redisplay the data from a file on a map axes. You can also use the mlayers GUI
to read and display the data from a file. To display the data in the
base workspace, use displaym. To display all the
display structures, use rootlayr; displaym(ans).
To display all of the display structures using the mlayers GUI,
type rootlayr; mlayers(ans).
The Close Button
The Close button closes the vmap0ui panel.
Examples
Launch
vmap0uiand automatically detect a CD-ROM on Microsoft® Windows:vmap0ui
Launch
vmap0uion Macintosh OS X (need to specify volume name):vmap0ui('Volumes/VMAP')