Using Layers

Layers partition a map into one or more overlays. Layers are like transparencies in that you can see all layers at the same time. Layers also let you isolate objects by placing them on separate layers. Layers are created and manipulated using the Object Manager and Map | New Layer.


Active Layer

Only one layer can be active at a time and most commands only apply to the active layer. For most commands, objects on other layers remain unaffected by any changes you make on the active layer. However, some commands do apply to all layers at the same time.


The commands that apply to all layers are:


One Thematic Map Per Layer

Each layer may contain a single thematic map and have only one data file associated with the layer. By using more than one layer, you can combine different map types to make multivariate thematic maps. For example, you could draw a scaled symbol map over the top of a hatch map to show two different variables. You might have a hatch map showing population and a scaled symbol map showing sales for the same areas.


Tips on Using Layers

There are several things you can accomplish when you use layers in MapViewer. When using layers, there are a few tips and tricks we can share that might help you.



Here are some possible applications.

image\nvhatsym_wmf.gif Making a map with different thematic maps on different layers. This way, you can display different data variables on a "single" map. You could show a hatch map on one layer, and a scaled symbol map on another layer.


image\4states.gif Using layers to emphasize particular boundaries. An example is to have two layers, one with the county outlines and one with the state outlines. In this situation, you can place the state boundaries on a top layer and use no fill for the states. Then give the states a heavy line style relative to the county boundaries.


image\4zoom.gif Show "zoomed" maps, with a small-scale map and large-scale map on the same page. This could be used to indicate a location from the small-scale map, and then present the data on the large-scale map.