Xextent

Xextent is a term used in geometry, computer graphics, and geographic information systems to describe the horizontal range occupied by an object along the x-axis. It is typically expressed as an interval [xmin, xmax], where xmin and xmax are the minimum and maximum x-coordinates of the object's footprint in a given coordinate system. The x-extent is commonly considered together with the y-extent, which describes the vertical range, and together they define the axis-aligned bounding box of the object.

In practice, the x-extent can be determined from a set of points by taking xmin as the smallest x-coordinate and xmax as the largest x-coordinate. For extended shapes such as polygons or raster extents, the x-extent is the horizontal projection of the bounding box that encloses the shape. The concept is used in various workflows, including plotting, mapping, data processing, and spatial queries, where quick checks of horizontal overlap help in pruning candidates for more detailed calculations.

Applications of xextent include cropping or clipping datasets to a region of interest, performing range queries, and implementing fast collision or intersection tests in graphics and simulations. It is important to note that xextent alone does not convey the complete position or size of an object; the y-extent (and, in 3D contexts, the z-extent) must be considered to describe the full footprint.

See also: extent, bounding box, axis-aligned bounding box, x-range, width.