Create Geospatial Tables
Vector data uses points, lines, polygons, and their nonspatial attributes to describe real-world events, locations and objects. For example, you can use a point and timestamp attribute to represent a tsunami event, a line and name attribute to represent a river location, and a polygon and age attribute to represent a building.
You can represent vector data by using geospatial tables. A geospatial
table is a
that contains a
Shape variable and attribute variables.
Shapevariable contains 2-D information about point, line, and polygon shapes. The
Shapevariable can contain combinations of shape types, but all the shapes must have the same coordinate reference system (CRS). The
Shapevariable must be the first variable of the table.
Represent shapes with coordinates in geographic CRSs by using
GeographicCRSproperty of each object contains the CRS as a
Represent shapes with coordinates in projected CRSs by using
ProjectedCRSproperty of each object contains the CRS as a
The attribute variables contain data such as names, classifications, and measurements.
For example, you can import the shapefile
represents a road network in Concord, MA, as a geospatial table. Each row of the table
maplineshape object with information about the line shape
and several attributes with information such as the street name, road class, and road
There are multiple ways to create geospatial tables. You can:
Read a geospatial table from a vector data file by using the
Read a table or timetable from a file containing pointwise data or well-known text (WKT) string representations of geometry by using the
readtimetablefunction, and then convert the table to a geospatial table by using the
Create a geospatial table by using the
timetablefunction. For more information about creating tables, see Create Tables and Assign Data to Them. For more information about creating timetables, see Create Timetables.
These examples show how to create geospatial tables using each of the listed processes.
Read Geospatial Table from File
Read a shapefile containing a network of road segments in Concord, MA as a geospatial table by using the
GT = readgeotable("concord_roads.shp");
View the first eight rows of the geospatial table. The
Shape variable contains information about the shapes. For this example, all the shapes are lines. The other variables contain attribute data.
Shape STREETNAME RT_NUMBER CLASS ADMIN_TYPE LENGTH ____________ _____________ _________ _____ __________ ______ maplineshape "" "" 6 0 67.264 maplineshape "WRIGHT FARM" "" 5 0 72.178 maplineshape "WRIGHT FARM" "" 5 0 43.965 maplineshape "WRIGHT FARM" "" 5 0 109.65 maplineshape "WRIGHT FARM" "" 5 0 18.019 maplineshape "" "" 6 0 58.444 maplineshape "WRIGHT FARM" "" 5 0 16.925 maplineshape "" "" 6 0 55.633
View the projected CRS for the line shapes. All shapes in a geospatial table must have the same CRS.
ans = projcrs with properties: Name: "NAD83 / Massachusetts Mainland" GeographicCRS: [1x1 geocrs] ProjectionMethod: "Lambert Conic Conformal (2SP)" LengthUnit: "meter" ProjectionParameters: [1x1 map.crs.ProjectionParameters]
View information about the line shape in the first row of the table.
ans = maplineshape with properties: NumParts: 1 Geometry: "line" CoordinateSystemType: "planar" ProjectedCRS: [1x1 projcrs]
Display the roads.
Create Geospatial Table from Table
Read data about tsunami events as a table by using the
readtable function. The coordinates of the tsunami source locations are in the
Longitude table variables.
T = readtable("tsunamis.xlsx");
Convert the table to a geospatial table by using the
table2geotable function. The function detects the
Longitude variables and uses them to create the
Shape variable of the table.
GT = table2geotable(T);
Shape variable of the geospatial table. The tsunami source locations are points in a geographic coordinate system.
ans = 162×1 geopointshape array with properties: NumPoints: [162×1 double] Latitude: [162×1 double] Longitude: [162×1 double] Geometry: "point" CoordinateSystemType: "geographic" GeographicCRS: 
Plot the source locations on a web map. Display the attributes for a shape by selecting a marker.
Create Geospatial Table from Arrays
Create a geospatial table containing the locations and names of cities.
Create an array of
geopointshape objects from column vectors of latitude and longitude coordinates. Specify the geographic CRS as the World Geodetic System of 1984, which has the EPSG code
lats = [35.7082 -22.8842 51.5074 39.9042 37.9838]'; lons = [139.6401 -43.3882 -0.1278 116.4074 23.7275]'; shape = geopointshape(lats,lons); shape.GeographicCRS = geocrs(4326)
shape = 5x1 geopointshape array with properties: NumPoints: [5x1 double] Latitude: [5x1 double] Longitude: [5x1 double] Geometry: "point" CoordinateSystemType: "geographic" GeographicCRS: [1x1 geocrs]
Specify the names of the cities as a column vector.
names = ["Tokyo" "Rio de Janeiro" "London" "Beijing" "Athens"]';
Create the geospatial table. The
Shape variable contains the
geopointshape objects and the
Name variable contains the names.
GT = table(shape,names,VariableNames=["Shape" "Name"])
GT=5×2 table Shape Name _______________________ ________________ (35.7082°N, 139.6401°E) "Tokyo" (22.8842°S, 43.3882°W) "Rio de Janeiro" (51.5074°N, 0.1278°W) "London" (39.9042°N, 116.4074°E) "Beijing" (37.9838°N, 23.7275°E) "Athens"
Verify that the table is a geospatial table.
ans = logical 1
Some functions that accept geospatial tables as input require the geospatial table
to contain shapes of a specific type. For example, the
function only accepts geospatial tables that contain geographic point, line, or