Mapping Toolbox

Map and Frame Limits

In the Mapping Toolbox, the map and frame limits are two related map axes properties that limit the map display to a defined region. The map latitude and longitude limits restrict the displayed parallels and meridians, while the frame limits control the extent of the frame around the displayed data. Any object that extends outside the frame limits is automatically trimmed.

The frame limits are also specified differently from the map limits. The map limits are in Greenwich coordinates referenced to an origin at the intersection of the Prime Meridian and the Equator, while the frame limits are in coordinates referenced to the center of the frame, which is the latitude and longitude of the map axes origin.

For all non-azimuthal projections, frame limits are specified as quadrangles ([latmin latmax] and [longmin longmax]) in the frame coordinate system. In the case of azimuthal projections, the frames are circular and are described by a polar coordinate system. One of the frame latitude limits must be a negative infinity (-Inf) to indicate an azimuthal frame (think of this as the center of the circle), while the other limit determines the radius of the circular frame (rlatmax). The longitude limits of azimuthal frames are inconsequential, since a full circle is always displayed.

If you are uncertain about the correct format for a particular projection frame limit, you can reset them to the default values using empty matrices.

Note    For non-azimuthal projections in the normal aspect, the map is limited to the minimum of the map and frame limits; hence, the two limits will coincide after evaluation. When changing one set of limits, you may want to clear the other set to get consistent limits.

The Map Grid

Switching Between Projections