2011

element (Oracle Spatial database) The basic building block of an Oracle
Spatial
geometry (Oracle Spatial database) (page 2064). The supported spatial
element types are points, line strings, and polygons. For example, elements
might model water wells (point clusters), roads (line strings), and county
boundaries (polygons).
elevation The vertical distance from a datum to a point or object on the
surface of the Earth. The datum is generally considered to be at sea level.
Equivalent to the Z coordinate in an XYZ coordinate system.
ellipsoid An approximation of the shape of the Earth that does not account
for variations caused by the nonuniform density of the earth. Synonymous
with
spheroid (page 2075). See also geoid (page 2064).
equal area A map projection in which every part, as well as the whole, has
the same area as the corresponding part on the earth, at the same reduced
scale. No flat map can be equal area and represent true shape.
equidistant projections Projections showing true distances only from the
center of the projection or along a special set of lines. No flat map can be both
equidistant and equal area.
exaggeration See
vertical exaggeration (page 2078).
explicit checkout The action of checking out features using the Check Out
Features command. See also checkout (page 2057), implicit checkout (page 2065).
export profile A file with a .epf extension that stores settings for an export
operation.
expression An automatic calculation used to specify values for URL, tooltip,
and feature labels. For example, you might create a text expression that
specifies a state name and population for a label. To express the population
in millions, you might apply a number expression that divides the population
value by 1,000,000.
expression evaluator The mechanism that analyzes the statement you enter
in the Expression box in the Output Report Options dialog box or the Property
Alteration dialog box.
external data Attribute data linked to a drawing object but contained in a
database apart from the drawing file. See also
attributes or attribute data (page
2055) and
object data (page 2070).
FDO Feature Data Objects (FDO) data access technology. An Autodesk software
standard and general purpose API for accessing features and geospatial data
regardless of the underlying data store. See also
feature (page 2063), feature class
(page 2063).
2062 | Glossary