Namespace NetTopologySuite.IO

Contains the interfaces for converting JTS objects to and from other formats.

The Net Topology Suite (NTS) is a .Net API that implements a core set of spatial data operations using an explicit precision model and robust geometric algorithms. NTS is intended to be used in the development of applications that support the validation, cleaning, integration and querying of spatial datasets.

NTS attempts to implement the OpenGIS Simple Features Specification (SFS) as accurately as possible. In some cases the SFS is unclear or omits a specification; in this case NTS attempts to choose a reasonable and consistent alternative. Differences from and elaborations of the SFS are documented in this specification.

Package Specification

Java Topology Suite Technical Specifications
OpenGIS Simple Features Specification for SQL

Classes

BEBinaryWriter

Extends the BinaryWriter class to allow writing values in the BigEndian format.

BiEndianBinaryReader

Extends the BinaryReader class to allow reading values in the specified format.

OrdinateFormat

Formats numeric values for ordinates in a consistent, accurate way.

The format has the following characteristics:

ParseException

Thrown by a WKTReader when a parsing problem occurs.

WKBHexFileReader

Reads a sequence of {@link Geometry}s in WKBHex format from a text file. Each WKBHex geometry must be on a single line The geometries in the file may be separated by any amount of whitespace and newlines.

WKBReader

Converts a Well-Known Binary byte data to a Geometry.

WKBWriter

Writes a Well-Known Binary byte data representation of a Geometry.

WKTConstants

Constants used in the WKT (Well-Known Text) format.

WKTFileReader

Reads a sequence of Geometrys in WKT format from a text file.

WKTReader

Converts a Well-Known Text string to a Geometry.

The WKTReader allows extracting Geometry objects from either input streams or internal strings. This allows it to function as a parser to read Geometry objects from text blocks embedded in other data formats (e.g. XML).

The Well-known Text format is defined in the OpenGIS Simple Features Specification for SQL .

As of version 2.0, NTS can read WKT syntax which specifies coordinate dimension Z, M or ZM as modifiers(e.g.POINT Z) or in the name of the geometry type(e.g.LINESTRINGZM). If the coordinate dimension is specified it will be set in the created geometry. If the coordinate dimension is not specified, the default behaviour is to create XYZ geometry(this is backwards compatible with older JTS versions). This can be altered to create XY geometry by setting IsOldNtsCoordinateSyntaxAllowed to false.

A reader can be set to ensure the input is structurally valid by setting FixStructure to true. This ensures that geometry can be constructed without errors due to missing coordinates. The created geometry may still be topologically invalid.

NOTE: There is an inconsistency in the SFS. The WKT grammar states that MultiPoints are represented by MULTIPOINT ( ( x y), (x y) ), but the examples show MultiPoints as MULTIPOINT ( x y, x y ). Other implementations follow the latter syntax, so NTS will adopt it as well. A WKTReader is parameterized by a GeometryFactory, to allow it to create Geometry objects of the appropriate implementation. In particular, the GeometryFactory will determine the PrecisionModel and SRID that is used. The WKTReader will convert the input numbers to the precise internal representation. WKTReader reads also non-standard LINEARRING tags.

WKTWriter

Outputs the textual representation of a Geometry. The WKTWriter outputs coordinates rounded to the precision model. No more than the maximum number of necessary decimal places will be output. The Well-known Text format is defined in the OpenGIS Simple Features Specification for SQL. A non-standard "LINEARRING" tag is used for LinearRings. The WKT spec does not define a special tag for LinearRings. The standard tag to use is "LINESTRING".

Structs

GeometryType

Lightweight class that handles OGC Geometry type declaration