A map extent defines the geographic boundaries for displaying GIS information within a map frame. These boundaries contain top, bottom, left, and right coordinates. These are the edges of the map extent. Map extents are affected by map scale. As you zoom in or out on a map, the map extent changes.
In some cases, you'll want to control the map extent. For instance, you might only be interested in a geographic subset of your data and want to limit the map user to this area. Or, you may want to limit users to a particular map scale while allowing them to pan to different locations. Also, you may want to derive the map extent of one map frame, for example, an inset map, based on the map extent of a different map frame.
Map frame display constraints and settings
When a map is inside a map frame, it has its own unique view, separate from any other view of that map. You can update the extent by activating the map frame and using the map navigation tools to pan and zoom to the desired extent.
To learn about activating a map frame, see Work with a map on a layout.
- To set map frame display constraints, ensure the layout is the active view.
- In the Contents pane, right-click the map frame and click Properties.
The Format Map Frame pane appears.
- In the Format Map Frame pane, click the Display Options button .
By default, there are no constraints on the map extent inside the frame. This means there are no limitations on the type of navigation allowed when the map frame is activated. However, you can lock certain aspects of the view so that they cannot be changed when the map frame is activated. You can also link one map frame's view to another. When any type of constraint is enabled, navigation while the map frame is activated is limited accordingly. For maps, the following settings can be set for extent coordinates, center coordinates, rotation, and scale.
The following types of Fixed constraints can be set:
- Extent—Sets the exact extent for maps. The map frame reshapes to conform if necessary, and navigation is unavailable when the map frame is activated.
- Center—Fixes the center point of the view. Zooming and rotating around the point are allowed, but panning is unavailable.
- Center and Scale—Sets the center point and scale of the map without restricting the extent. Rotation is the only navigation available when the map frame is activated.
- Scale—Fixes the map scale. Panning is allowed, but zooming is unavailable.
These constraints only apply to maps. The constraints for scenes are limited to None.
This option keeps the map extent constant. The geographic boundaries of the map—the top, bottom, left, and right coordinates—are specifically defined. The values displayed will be based on the map unit type.
A fixed extent can be established as follows:
- Rotation—Changes the angle of the map in degrees. The map frame remains in the same position.
- The current extent of the map frame.
- The combined extent of all the features in a specific layer.
- The combined extent of all the features in a specific layer visible in the current map extent.
- The combined extent of all selected features in a specific layer.
- A rectangle defined by specific coordinates that you supply.
Map navigation is restricted for the map frame. You cannot pan, zoom, or use bookmarks. If you choose this option, appropriate map navigation tools and commands will be unavailable. If you resize the map frame on the page layout, the map scale changes to keep the extent constant. You can increase the size of the map frame by dragging its handles across the page.
Center and Scale
It is important to understand the difference between Center and Scale and Extent. When Center and Scale is locked, the extent of the map is determined by the shape of the map frame. If it's resized, the extent changes, but the center point and scale do not. When Extent is locked, the height and width ratio of the map frame is also locked, and resizing the map frame causes the scale or camera height of the view to change, but the extent does not change. The relationship between the map frame and the extent is the key difference between locking Extent and locking Center and Scale.
This option keeps the map scale constant. You can enter the scale in absolute format, such as 1:34,000, or in relative format, such as 1 inch = 5 miles. You can enter scales in absolute or relative format irrespective of what format the scale control is currently using. When you enter a scale, it is automatically converted to the current scale format.
When you type scales into this field, they remain at the top of the list for the duration of your session so that they can be easily accessed again. To permanently add or remove predefined scales to or from this list, use the Customize option, which also lets you change the format used to display scales. Customizations you make to the list of predefined scales and how scale is displayed are stored as ArcGIS Pro settings on your computer; they are not stored in the project itself, so they are not available if the project is opened on a different machine.
The following scale formatting options are supported:
- In absolute format, the 1: prefix and thousand separators can be present or absent: 1:1,000,000 or 1,000,000 or 1:1000000 or 1000000.
- Any character or word can be used as the separator in absolute format: 1:25000 or 1 - 25000 or 1 to 25000 or 1/25000.
- You can use the following unit abbreviations in relative format: In, inch symbol ("), ft, foot symbol ('), pt, yd, mi, nm, mm, cm, m, km, dd, dm.
- You can specify units using their full name in relative formats. The scale control recognizes units by the first part of their names, so it is not affected if unit names are plural. You can type any characters after the first part of the name shown here: inch, feet, poin, yard, mile, naut, mill, cent, mete, metr, kilo, decima, decime.
- Values can be specified in any order: 1:1,000,000 or 1, 000, 000:1 or 1 to 5mi or 5mi to 1.
- One can be given as a number or a word: 1 to 1,000,000 or One to 1,000,000 or One inch = 5mi.
- Any word or character can be used for equals in relative formats. A space isn't required between a numeric value and the unit's abbreviation or name: One inch = 5 miles or 1in equals 5mi or 1inch = 5miles or 5 mi to 1 in.
You can pan the map to a new location, but you cannot zoom to a new map scale. If you resize the map frame on the page layout, the map scale remains. The geographic area displayed on the map changes. When using fixed scale, you can pan the map and change the map frame extent, and the map scale remains the same.
Linked Map Frame
If the layout contains more than one map frame, you can enable one-directional links between map frames to tie their views together.
The following types of Linked Map Frame constraints can be set:
- Extent—Matches the extents of the map frames. The child frame does not resize to match the exact extent of the parent; instead, it adjusts scale as needed to contain the entire view of the parent frame. All navigation tools are unavailable.
- Center—Links the center points of the map frames. If the parent frame is navigated, the child frame pans to keep the center points in sync. When the map frame is activated, zooming is allowed but panning is unavailable.
- Scale—Links the map scale. Panning is allowed, but zooming is unavailable.
- Center and Scale—Links the center point and scale of two views without restricting the extent. Rotation is the only navigation available when the map frame is activated.
- Rotation—Changes the angle of the map in degrees. The map frame remains in the same position. By default, rotation is synchronized with the other map frame and can be unchecked and controlled manually.
Use margin with linked map frame extent
Extent can be buffered by a specified margin. The margin can be specified in map units, in page units, or as a percentage of the linked map frame's extent. You can also use intersection of specified layer features (from the map frame's extent you are customizing) with the extent of the selected (other) map frame.
Margin is measured from the edge of the selected map frame's geographic extent to the closest edge of the map frame's properties you're editing. The margin value is applied to each side of the horizontal and vertical axes. Since the aspect ratios (width and height) of two different map frames are not the same, the margin is only applied along one axis. The margin will be larger along the other axis. The size of the difference depends on the difference in aspect ratio. If the two map frames share the same aspect ratio, the margin along the vertical and horizontal axes will be the same. If you use map units, you'll see similar results.
You can also derive a map's extent by taking the combined extent of features from a specified layer that intersect with the extent of another map frame. For example, you have divided a city's geography into a grid of 60 cells. The map contains a layer that represents this grid, and you want to map each individual grid cell. You also want to include an inset map highlighting this grid cell's location. One way to do this is to use an extent locator. The following example shows a map for grid cell E4. The inset map at the lower right shows all grids and highlights grid E4 in a red outline.Learn more about using extent indicators
Set a layer with linked map frame extent
Perhaps you don't want to display all grids in the inset map; you only want to display the adjoining, or intersecting, grid cells in your inset map. You can do this by defining the extent of the inset map to use the other map frame (the main map) and to use an intersecting layer. The inset map will zoom to the extent of the geographic extent of the other map frame plus the combined geographic extent of each feature in the selected layer that intersects the extent of the other map frame. This can be combined with the assigned margin.
As you can see in the following example, the inset map highlights the current grid cell displayed in the main map and displays the surrounding cells. The inset map changes accordingly based on the current extent of the main map. This can be very useful when you're using Map Series.
Be aware that the scale of the inset map can change. In the following example, there is only one intersecting feature. Compared to the inset map scale for grid cell E4, which has GridParcels features on all sides, the inset map scale for grid cell F9 is smaller, since this grid cell has only three intersecting features. Map frames using intersecting features to determine their extent will experience scale changes depending on the number of features that intersect and their combined extent.
The map extent updates if the geographic extent of the active map frame changes. This is important if you're using Map Series, which allows you to quickly create a series of layout pages from a single layout. A feature layer, or index layer, divides the map into sections and generates one page of output per section.
When Map Series is enabled, the primary map frame drives the map extent for the pages. You cannot interactively change this map frame's extent through map navigation tools or commands. However, you can still change the map extent properties for any secondary, or inset, maps.
Set an extent constraint
To set an extent constraint, use the map frame Properties and Map Frame Display Options.
- Right-click the map frame and click Properties to open the Format Map Frame pane.
- In the Format Map Frame pane, click Map Frame Display Options.
- Set the Constraint to None, Fixed, or Linked Map Frame.
Depending on which Fixed or Linked map frame extent type is chosen, options for setting the Layer, Margin, and Map Frame appear.
- After you've chosen a constraint type, set the appropriate values.
- Set Location Settings for center, scale, and rotation where applicable, and click Extent to set the extent of the map frame.