How to display maps and tables & zoom

In a Catalog, maps and tables are preceded by the following icons:

for raster maps,

for polygon maps,

for segment maps,

for point maps,

for tables.

To display maps and tables in new windows:

You can also click the Show Map button in the toolbar of the Main window.

Before a map is displayed, some display options have to be specified, then a map is displayed in a new map window.

A table is directly displayed in a new table window.

To add maps to an existing map window:

Before the extra layer is displayed, some display options have to be specified. Then, the selected point, segment or polygon map is displayed on top of the other layers that are currently shown in the map window.

Similarly, when the map window already displays a raster map (or a map list), and you add another raster map (or map list) with the same georeference to the map window, then the selected raster map (or map list) will also be added to the map window.

 

Tip: In the Display Options dialog box of a layer, you can specify whether a layer has to be displayed with a certain transparency. If you use the Transparency option, any layer that has been added to the map window before, e.g. an image or a shadow map, will remain partly visible through the transparent layer. In this manner, you can display thematic information on top of images, a shadow map etc. and view both types of information simultaneously. Click the following link for an Example of transparent layers.

To show a map by one of its attributes:

Instead of showing the units in a raster, polygon, segment or point map, you can also display the attribute values of these units in a map window. The raster, polygon, segment or point map should use a class or ID domain and an attribute table should be linked to the map or to its domain.

To retrieve specific elements of polygon, segment or point maps:

Instead of showing all units in a polygon, segment or point map, you can selectively display only those polygons, segments or points that have certain class names or class codes, IDs or values. Using a mask is a powerful search method to retrieve only the polygons, segments or points of interest.

For more information, see How to use masks.

When you want to retrieve specific classes, identifiers or values of a raster maps, you can type a MapCalc formula on the command using the INMASK function.

To zoom in on maps displayed in a map window or in a map editor:

The mouse pointer changes into a magnifying-glass with a large plus inside, then:

 

Tip: You can also use the overview window in a map window to zoom in.

To zoom in, you can also press CTRL + I on the keyboard: ILWIS will automatically zoom in at the center of the map window with a factor 2. You can then use the PgUp and PgDn keys on the keyboard to scroll vertically, and the Home and End keys to scroll horizontally. For more information, see Map window : Zoom in.

To zoom out or to display the entire map again in the map window, select the Zoom Out or Entire map commands on the Options menu or use the Zoom Out or the Entire map button in the toolbar.

The status bar gives a brief explanation on the effect of a button in a toolbar, when the mouse pointer is located above one.

 

Tip: To speed up the display of large raster map, for instance maps that have more than a few thousand lines and columns, you can create pyramid layers. For more information, refer to ILWIS objects : Raster maps - Pyramid layers.

See also: