Setting the Zoom Layering - MapInfo_Pro - 2023

Sometimes you want a map layer to display only at certain zoom levels. Zoom layering controls the display of a map layer so that it displays only when the map's zoom level falls within a preset distance.

For example, you have a layer of streets and a layer of postal code boundaries. When you zoom out past 10 or so miles, the streets look like a black smudge in the window. This is because the zoom (window width) is too wide to show detailed street maps. Use zoom layering to tell MapInfo Pro to display the street layer only when the zoom is set to a distance that allows you to see the street detail properly, for instance, less than 5 miles.

The first map does not have zoom layering set for its street layer. At a zoom of 15 miles across, notice how difficult it is to see any detail. The second map has zoom layering set to display the streets when the zoom is less than five miles. Therefore, the streets layer does not display when the window is set at 15 miles.

To set zoom layering:

1. Make the target table editable. On the HOME tab, in the Windows group, click Tool Windows, and click Explorer from the list, to open the Explorer window.
2. In the Maps list, double-click the layer name for which to set zoom layering. The Layer Properties dialog box displays.
3. On the Layer Display tab, click the Display within Zoom Range check box to activate the zoom distance boxes.
4. Specify a minimum and maximum distance within which you want the layer to display. Note that you cannot change display settings for more than one layer at a time.
5. Click OK to save your settings.

You can display different layers in the same Map window at different zoom levels. For example, you have a layer of streets, a layer of county boundaries, and a layer of state boundaries. You want the streets layer to be visible only when the zoom level is less than eight miles. You want the county boundary layer to display when the zoom level falls between 20 miles and 200 miles. You want the states boundary layer to be visible only when the zoom level is greater than 100 miles. You can set a different zoom level for every layer in your Map window.

Changing a Map's Zoom Level

You change a map's zoom level or scale by specifying certain parameters in the Change View dialog box.

To scale your map:

1. Right-click on the map and select Change View from the pop-up menu to open the Change View dialog box.
2. Type the new Zoom [window width].
3. Type the new Map scale.
4. Type the new X and Y Center of window coordinates to position your map.
5. Click OK.

The Change View dialog box allows you to set various parameters of the map including:

• Display the current zoom, scale or cursor position in the status bar (the default unit of distance is miles. This is set on the PRO tab, by clicking Options, and Map Window).
• Change the zoom, scale, and the center point of the current map view.
• Behavior of the map when you resize the window.
• Resize the map to fit the new window, keeping the view the same.
• Set the map to preserve the current scale, so that resizing the window has the effect of letting you see more or less of the map.

Zooming In on a Map

To zoom in on a Map window:

1. On the MAP tab, in the Navigate group, click Zoom In.
2. Do one of the following:
   • Click on the center of the area you want to zoom in on. The area magnifies by a factor of two. This point will be at the center of the map in the zoomed-in view. You can repeat this procedure until you have the desired level of enlargement.
   • Draw a marquee around the area by dragging the mouse diagonally across it. MapInfo Pro then enlarges the selected area to fill the Map window. The area enclosed by the dotted rectangle is the area that is being zoomed in on.

When you are done, the area enclosed by the Zoom In marquee occupies the entire map. However, the aspect ratio is not changed, so if you choose an area that has a very different shape from the window, you will end up seeing a much wider or taller area of the map than you selected.

Zooming Out on a Map

To zoom out on a Map window:

1. On the MAP tab, in the Navigate group, click Zoom Out.
2. Do one of the following:
   • Click on the center of the area you want to zoom out from. This will increase the visible area of the map by a linear factor of two. The map is redrawn placing the point at the center of the Map window in the zoomed-out view. You can repeat this procedure as desired.
   • Draw a marquee in the Map window by diagonally dragging the mouse. The map is redrawn so that the area you started with is positioned within the marquee area and more of the map appears around it.

The Zoom Out marquee shows the area that will be occupied by the current map image when the zoom out is complete. That is, the current map image is reduced to that size, and more of the map displays.