Map View
User Guide GeoDMS GUI - map view
The map view presents data items that can be geographically located. Each map view has a projection, indicating a coordinate system. For instance in Dutch applications usually the "Rijks Driehoek (RD)" coordinate system is used. EPSG codes are used as identifiers for the most common coordinate systems. The EPSG code is shown in the title of each map view, if configured as SpatialReference property for the base unit of the coordinate system.
A map view consists of layers, each layer is related to one or more data items. All geographically related data items using the same projection can be combined in the same map view window. They can also be opened in multiple separate map views. The number of opened map views is not limited.
To view data in a map view, first activate a tree item that can be geographically related (indicated with a map icon 
).
A new map can be created or a layer can be added to an existing map by activating one of the following actions listed in the table.
| action | no active map view | active map view |
|---|---|---|
| double click on active item | new map window | added to active map view with same coordinate system |
| main/pop-up menu option default view | new map window | added to active map view with same coordinate system |
| main/pop-up menu option map view | new map window | new map window |
| Ctrl-M on active item | new map window | new map window |
| drag and drop to view | new map window | added to active map view with same coordinate system |
A map view consists of one or multiple layers, with coordinates expressed in the same coordinate system.
In the GeoDMS a distinction can be made in the following layer types:
Layers use to present data related to a geographic domain. Such a domain can be visualised in a map view with grid cells (for grid domains), polygons, arcs or points (for one-dimensional domains) as in the following example:
Examples of data layers with grid, polygons, arcs and points data
In these layers, the grid cell, polygons, arcs and/or points are visualized with one or multiple visualization styles (colors, symbols, size etc.). The possible styles are dependent on the layer type.
The style values refer to classes in a classification scheme. This implies that a palette (e.g. color, size, symbol) and, if the data item is not yet classified, a classification is needed to visualize a data item as a thematic layer. If no classification is found for the data item or its values unit (see chapter 10 for more information), a data item cannot be visualized thematically. Layers can be activated with the actions listed in paragraph 7.1. The grid layer type is activated for each numeric data item with a grid domain as domain unit. For the vector data types (polygon, arc and point), the geographic format specified for the values User Guide GeoDMS GUI 7.309 36 unit of the feature data item, determines if the data is visualized as point, arc or polygon (see the modeler’s guide how to configure these values types). A specific theme of a layer is a text label. Text labels can be used for polygon and point layers.
A reference grid layer can be configured as a background layer. This means in all map views this layer is visualized automatically when the view is created (see the modeler’s guide for how to configure a default layer)
