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diff --git a/parts/django/docs/ref/contrib/gis/gdal.txt b/parts/django/docs/ref/contrib/gis/gdal.txt deleted file mode 100644 index 1ce21d9..0000000 --- a/parts/django/docs/ref/contrib/gis/gdal.txt +++ /dev/null @@ -1,1114 +0,0 @@ -.. _ref-gdal: - -======== -GDAL API -======== - -.. module:: django.contrib.gis.gdal - :synopsis: GeoDjango's high-level interface to the GDAL library. - -`GDAL`__ stands for **G**\ eospatial **D**\ ata **A**\ bstraction **L**\ ibrary, -and is a veritable "swiss army knife" of GIS data functionality. A subset -of GDAL is the `OGR`__ Simple Features Library, which specializes -in reading and writing vector geographic data in a variety of standard -formats. - -GeoDjango provides a high-level Python interface for some of the -capabilities of OGR, including the reading and coordinate transformation -of vector spatial data. - -.. note:: - - Although the module is named ``gdal``, GeoDjango only supports - some of the capabilities of OGR. Thus, none of GDAL's features - with respect to raster (image) data are supported at this time. - -__ http://www.gdal.org/ -__ http://www.gdal.org/ogr/ - -Overview -======== - -Sample Data ------------ - -The GDAL/OGR tools described here are designed to help you read in -your geospatial data, in order for most of them to be useful you have -to have some data to work with. If you're starting out and don't yet -have any data of your own to use, GeoDjango comes with a number of -simple data sets that you can use for testing. This snippet will -determine where these sample files are installed on your computer:: - - >>> import os - >>> import django.contrib.gis - >>> GIS_PATH = os.path.dirname(django.contrib.gis.__file__) - >>> CITIES_PATH = os.path.join(GIS_PATH, 'tests/data/cities/cities.shp') - -Vector Data Source Objects -========================== - -``DataSource`` --------------- - -:class:`DataSource` is a wrapper for the OGR data source object that -supports reading data from a variety of OGR-supported geospatial file -formats and data sources using a simple, consistent interface. Each -data source is represented by a :class:`DataSource` object which contains -one or more layers of data. Each layer, represented by a :class:`Layer` -object, contains some number of geographic features (:class:`Feature`), -information about the type of features contained in that layer (e.g. -points, polygons, etc.), as well as the names and types of any -additional fields (:class:`Field`) of data that may be associated with -each feature in that layer. - -.. class:: DataSource(ds_input) - - The constructor for ``DataSource`` just a single parameter: the path of - the file you want to read. However, OGR - also supports a variety of more complex data sources, including - databases, that may be accessed by passing a special name string instead - of a path. For more information, see the `OGR Vector Formats`__ - documentation. The :attr:`name` property of a ``DataSource`` - instance gives the OGR name of the underlying data source that it is - using. - - Once you've created your ``DataSource``, you can find out how many - layers of data it contains by accessing the :attr:`layer_count` property, - or (equivalently) by using the ``len()`` function. For information on - accessing the layers of data themselves, see the next section:: - - >>> from django.contrib.gis.gdal import DataSource - >>> ds = DataSource(CITIES_PATH) - >>> ds.name # The exact filename may be different on your computer - '/usr/local/lib/python2.6/site-packages/django/contrib/gis/tests/data/cities/cities.shp' - >>> ds.layer_count # This file only contains one layer - 1 - - .. attribute:: layer_count - - Returns the number of layers in the data source. - - .. attribute:: name - - Returns the name of the data source. - -__ http://www.gdal.org/ogr/ogr_formats.html - -``Layer`` ---------- - -.. class:: Layer - - ``Layer`` is a wrapper for a layer of data in a ``DataSource`` object. - You never create a ``Layer`` object directly. Instead, you retrieve - them from a :class:`DataSource` object, which is essentially a standard - Python container of ``Layer`` objects. For example, you can access a - specific layer by its index (e.g. ``ds[0]`` to access the first - layer), or you can iterate over all the layers in the container in a - ``for`` loop. The ``Layer`` itself acts as a container for geometric - features. - - Typically, all the features in a given layer have the same geometry type. - The :attr:`geom_type` property of a layer is an :class:`OGRGeomType` - that identifies the feature type. We can use it to print out some basic - information about each layer in a :class:`DataSource`:: - - >>> for layer in ds: - ... print 'Layer "%s": %i %ss' % (layer.name, len(layer), layer.geom_type.name) - ... - Layer "cities": 3 Points - - The example output is from the cities data source, loaded above, which - evidently contains one layer, called ``"cities"``, which contains three - point features. For simplicity, the examples below assume that you've - stored that layer in the variable ``layer``:: - - >>> layer = ds[0] - - .. attribute:: name - - Returns the name of this layer in the data source. - - >>> layer.name - 'cities' - - .. attribute:: num_feat - - Returns the number of features in the layer. Same as ``len(layer)``:: - - >>> layer.num_feat - 3 - - .. attribute:: geom_type - - Returns the geometry type of the layer, as an :class:`OGRGeomType` - object:: - - >>> layer.geom_type.name - 'Point' - - .. attribute:: num_fields - - Returns the number of fields in the layer, i.e the number of fields of - data associated with each feature in the layer:: - - >>> layer.num_fields - 4 - - .. attribute:: fields - - Returns a list of the names of each of the fields in this layer:: - - >>> layer.fields - ['Name', 'Population', 'Density', 'Created'] - - .. attribute field_types - - Returns a list of the data types of each of the fields in this layer. - These are subclasses of ``Field``, discussed below:: - - >>> [ft.__name__ for ft in layer.field_types] - ['OFTString', 'OFTReal', 'OFTReal', 'OFTDate'] - - .. attribute:: field_widths - - Returns a list of the maximum field widths for each of the fields in - this layer:: - - >>> layer.field_widths - [80, 11, 24, 10] - - .. attribute:: field_precisions - - Returns a list of the numeric precisions for each of the fields in - this layer. This is meaningless (and set to zero) for non-numeric - fields:: - - >>> layer.field_precisions - [0, 0, 15, 0] - - .. attribute:: extent - - Returns the spatial extent of this layer, as an :class:`Envelope` - object:: - - >>> layer.extent.tuple - (-104.609252, 29.763374, -95.23506, 38.971823) - - .. attribute:: srs - - Property that returns the :class:`SpatialReference` associated - with this layer:: - - >>> print layer.srs - GEOGCS["GCS_WGS_1984", - DATUM["WGS_1984", - SPHEROID["WGS_1984",6378137,298.257223563]], - PRIMEM["Greenwich",0], - UNIT["Degree",0.017453292519943295]] - - If the :class:`Layer` has no spatial reference information associated - with it, ``None`` is returned. - - .. attribute:: spatial_filter - - .. versionadded:: 1.2 - - Property that may be used to retrieve or set a spatial filter for this - layer. A spatial filter can only be set with an :class:`OGRGeometry` - instance, a 4-tuple extent, or ``None``. When set with something - other than ``None``, only features that intersect the filter will be - returned when iterating over the layer:: - - >>> print layer.spatial_filter - None - >>> print len(layer) - 3 - >>> [feat.get('Name') for feat in layer] - ['Pueblo', 'Lawrence', 'Houston'] - >>> ks_extent = (-102.051, 36.99, -94.59, 40.00) # Extent for state of Kansas - >>> layer.spatial_filter = ks_extent - >>> len(layer) - 1 - >>> [feat.get('Name') for feat in layer] - ['Lawrence'] - >>> layer.spatial_filter = None - >>> len(layer) - 3 - - .. method:: get_fields() - - A method that returns a list of the values of a given field for each - feature in the layer:: - - >>> layer.get_fields('Name') - ['Pueblo', 'Lawrence', 'Houston'] - - .. method:: get_geoms([geos=False]) - - A method that returns a list containing the geometry of each feature - in the layer. If the optional argument ``geos`` is set to ``True`` - then the geometries are converted to :class:`~django.contrib.gis.geos.GEOSGeometry` - objects. Otherwise, they are returned as :class:`OGRGeometry` objects:: - - >>> [pt.tuple for pt in layer.get_geoms()] - [(-104.609252, 38.255001), (-95.23506, 38.971823), (-95.363151, 29.763374)] - - .. method:: test_capability(capability) - - Returns a boolean indicating whether this layer supports the - given capability (a string). Examples of valid capability strings - include: ``'RandomRead'``, ``'SequentialWrite'``, ``'RandomWrite'``, - ``'FastSpatialFilter'``, ``'FastFeatureCount'``, ``'FastGetExtent'``, - ``'CreateField'``, ``'Transactions'``, ``'DeleteFeature'``, and - ``'FastSetNextByIndex'``. - -``Feature`` ------------ - -.. class:: Feature - - - ``Feature`` wraps an OGR feature. You never create a ``Feature`` - object directly. Instead, you retrieve them from a :class:`Layer` object. - Each feature consists of a geometry and a set of fields containing - additional properties. The geometry of a field is accessible via its - ``geom`` property, which returns an :class:`OGRGeometry` object. A ``Feature`` - behaves like a standard Python container for its fields, which it returns as - :class:`Field` objects: you can access a field directly by its index or name, - or you can iterate over a feature's fields, e.g. in a ``for`` loop. - - .. attribute:: geom - - Returns the geometry for this feature, as an ``OGRGeometry`` object:: - - >>> city.geom.tuple - (-104.609252, 38.255001) - - .. attribute:: get - - A method that returns the value of the given field (specified by name) - for this feature, **not** a ``Field`` wrapper object:: - - >>> city.get('Population') - 102121 - - .. attribute:: geom_type - - Returns the type of geometry for this feature, as an :class:`OGRGeomType` - object. This will be the same for all features in a given layer, and - is equivalent to the :attr:`Layer.geom_type` property of the - :class:`Layer`` object the feature came from. - - .. attribute:: num_fields - - Returns the number of fields of data associated with the feature. - This will be the same for all features in a given layer, and is - equivalent to the :attr:`Layer.num_fields` property of the - :class:`Layer` object the feature came from. - - .. attribute:: fields - - Returns a list of the names of the fields of data associated with the - feature. This will be the same for all features in a given layer, and - is equivalent to the :attr:`Layer.fields` property of the :class:`Layer` - object the feature came from. - - .. attribute:: fid - - Returns the feature identifier within the layer:: - - >>> city.fid - 0 - - .. attribute:: layer_name - - Returns the name of the :class:`Layer` that the feature came from. - This will be the same for all features in a given layer:: - - >>> city.layer_name - 'cities' - - .. attribute:: index - - A method that returns the index of the given field name. This will be - the same for all features in a given layer:: - - >>> city.index('Population') - 1 - -``Field`` ---------- - -.. class:: Field - - .. attribute:: name - - Returns the name of this field:: - - >>> city['Name'].name - 'Name' - - .. attribute:: type - - Returns the OGR type of this field, as an integer. The - ``FIELD_CLASSES`` dictionary maps these values onto - subclasses of ``Field``:: - - >>> city['Density'].type - 2 - - .. attribute:: type_name - - Returns a string with the name of the data type of this field:: - - >>> city['Name'].type_name - 'String' - - .. attribute:: value - - Returns the value of this field. The ``Field`` class itself - returns the value as a string, but each subclass returns the - value in the most appropriate form:: - - >>> city['Population'].value - 102121 - - .. attribute:: width - - Returns the width of this field:: - - >>> city['Name'].width - 80 - - .. attribute:: precision - - Returns the numeric precision of this field. This is meaningless (and - set to zero) for non-numeric fields:: - - >>> city['Density'].precision - 15 - - .. method:: as_double() - - Returns the value of the field as a double (float):: - - >>> city['Density'].as_double() - 874.7 - - .. method:: as_int() - - Returns the value of the field as an integer:: - - >>> city['Population'].as_int() - 102121 - - .. method:: as_string() - - Returns the value of the field as a string:: - - >>> city['Name'].as_string() - 'Pueblo' - - .. method:: as_datetime() - - Returns the value of the field as a tuple of date and time components:: - - >>> city['Created'].as_datetime() - (c_long(1999), c_long(5), c_long(23), c_long(0), c_long(0), c_long(0), c_long(0)) - -``Driver`` ----------- - -.. class:: Driver(dr_input) - - The ``Driver`` class is used internally to wrap an OGR :class:`DataSource` driver. - - .. attribute:: driver_count - - Returns the number of OGR vector drivers currently registered. - - -OGR Geometries -============== - -``OGRGeometry`` ---------------- - -:class:`OGRGeometry` objects share similar functionality with -:class:`~django.contrib.gis.geos.GEOSGeometry` objects, and are thin -wrappers around OGR's internal geometry representation. Thus, -they allow for more efficient access to data when using :class:`DataSource`. -Unlike its GEOS counterpart, :class:`OGRGeometry` supports spatial reference -systems and coordinate transformation:: - - >>> from django.contrib.gis.gdal import OGRGeometry - >>> polygon = OGRGeometry('POLYGON((0 0, 5 0, 5 5, 0 5))') - -.. class:: OGRGeometry(geom_input[, srs=None]) - - This object is a wrapper for the `OGR Geometry`__ class. - These objects are instantiated directly from the given ``geom_input`` - parameter, which may be a string containing WKT or HEX, a ``buffer`` - containing WKB data, or an :class:`OGRGeomType` object. These objects - are also returned from the :class:`Feature.geom` attribute, when - reading vector data from :class:`Layer` (which is in turn a part of - a :class:`DataSource`). - - __ http://www.gdal.org/ogr/classOGRGeometry.html - - .. classmethod:: from_bbox(bbox) - - .. versionadded:: 1.1 - - Constructs a :class:`Polygon` from the given bounding-box (a 4-tuple). - - .. method:: __len__ - - Returns the number of points in a :class:`LineString`, the - number of rings in a :class:`Polygon`, or the number of geometries in a - :class:`GeometryCollection`. Not applicable to other geometry types. - - .. method:: __iter__ - - Iterates over the points in a :class:`LineString`, the rings in a - :class:`Polygon`, or the geometries in a :class:`GeometryCollection`. - Not applicable to other geometry types. - - .. method:: __getitem__ - - Returns the point at the specified index for a :class:`LineString`, the - interior ring at the specified index for a :class:`Polygon`, or the geometry - at the specified index in a :class:`GeometryCollection`. Not applicable to - other geometry types. - - .. attribute:: dimension - - Returns the number of coordinated dimensions of the geometry, i.e. 0 - for points, 1 for lines, and so forth:: - - >> polygon.dimension - 2 - - .. attribute:: coord_dim - - .. versionchanged:: 1.2 - - Returns or sets the coordinate dimension of this geometry. For - example, the value would be 2 for two-dimensional geometries. - - .. note:: - - Setting this property is only available in versions 1.2 and above. - - .. attribute:: geom_count - - Returns the number of elements in this geometry:: - - >>> polygon.geom_count - 1 - - .. attribute:: point_count - - Returns the number of points used to describe this geometry:: - - >>> polygon.point_count - 4 - - .. attribute:: num_points - - Alias for :attr:`point_count`. - - .. attribute:: num_coords - - Alias for :attr:`point_count`. - - .. attribute:: geom_type - - Returns the type of this geometry, as an :class:`OGRGeomType` object. - - .. attribute:: geom_name - - Returns the name of the type of this geometry:: - - >>> polygon.geom_name - 'POLYGON' - - .. attribute:: area - - Returns the area of this geometry, or 0 for geometries that do not - contain an area:: - - >>> polygon.area - 25.0 - - .. attribute:: envelope - - Returns the envelope of this geometry, as an :class:`Envelope` object. - - .. attribute:: extent - - Returns the envelope of this geometry as a 4-tuple, instead of as an - :class:`Envelope` object:: - - >>> point.extent - (0.0, 0.0, 5.0, 5.0) - - .. attribute:: srs - - This property controls the spatial reference for this geometry, or - ``None`` if no spatial reference system has been assigned to it. - If assigned, accessing this property returns a :class:`SpatialReference` - object. It may be set with another :class:`SpatialReference` object, - or any input that :class:`SpatialReference` accepts. Example:: - - >>> city.geom.srs.name - 'GCS_WGS_1984' - - .. attribute:: srid - - Returns or sets the spatial reference identifier corresponding to - :class:`SpatialReference` of this geometry. Returns ``None`` if - there is no spatial reference information associated with this - geometry, or if an SRID cannot be determined. - - .. attribute:: geos - - Returns a :class:`~django.contrib.gis.geos.GEOSGeometry` object - corresponding to this geometry. - - .. attribute:: gml - - Returns a string representation of this geometry in GML format:: - - >>> OGRGeometry('POINT(1 2)').gml - '<gml:Point><gml:coordinates>1,2</gml:coordinates></gml:Point>' - - .. attribute:: hex - - Returns a string representation of this geometry in HEX WKB format:: - - >>> OGRGeometry('POINT(1 2)').hex - '0101000000000000000000F03F0000000000000040' - - .. attribute:: json - - Returns a string representation of this geometry in JSON format:: - - >>> OGRGeometry('POINT(1 2)').json - '{ "type": "Point", "coordinates": [ 1.000000, 2.000000 ] }' - - - .. attribute:: kml - - .. versionadded:: 1.1 - - Returns a string representation of this geometry in KML format. - - .. attribute:: wkb_size - - Returns the size of the WKB buffer needed to hold a WKB representation - of this geometry:: - - >>> OGRGeometry('POINT(1 2)').wkb_size - 21 - - .. attribute:: wkb - - Returns a ``buffer`` containing a WKB representation of this geometry. - - .. attribute:: wkt - - Returns a string representation of this geometry in WKT format. - - .. attribute:: ewkt - - .. versionadded:: 1.2 - - Returns the EWKT representation of this geometry. - - .. method:: clone() - - Returns a new :class:`OGRGeometry` clone of this geometry object. - - .. method:: close_rings() - - If there are any rings within this geometry that have not been closed, - this routine will do so by adding the starting point to the end:: - - >>> triangle = OGRGeometry('LINEARRING (0 0,0 1,1 0)') - >>> triangle.close_rings() - >>> triangle.wkt - 'LINEARRING (0 0,0 1,1 0,0 0)' - - .. method:: transform(coord_trans, clone=False) - - Transforms this geometry to a different spatial reference system. May - take a :class:`CoordTransform` object, a :class:`SpatialReference` object, - or any other input accepted by :class:`SpatialReference` (including - spatial reference WKT and PROJ.4 strings, or an integer SRID). - By default nothing is returned and the geometry is transformed in-place. - However, if the `clone` keyword is set to ``True`` then a transformed clone - of this geometry is returned instead. - - .. method:: intersects(other) - - Returns ``True`` if this geometry intersects the other, otherwise returns - ``False``. - - .. method:: equals(other) - - Returns ``True`` if this geometry is equivalent to the other, otherwise returns - ``False``. - - .. method:: disjoint(other) - - Returns ``True`` if this geometry is spatially disjoint to (i.e. does - not intersect) the other, otherwise returns ``False``. - - .. method:: touches(other) - - Returns ``True`` if this geometry touches the other, otherwise returns - ``False``. - - .. method:: crosses(other) - - Returns ``True`` if this geometry crosses the other, otherwise returns - ``False``. - - .. method:: within(other) - - Returns ``True`` if this geometry is contained within the other, otherwise returns - ``False``. - - .. method:: contains(other) - - Returns ``True`` if this geometry contains the other, otherwise returns - ``False``. - - .. method:: overlaps(other) - - Returns ``True`` if this geometry overlaps the other, otherwise returns - ``False``. - - .. method:: boundary - - The boundary of this geometry, as a new :class:`OGRGeometry` object. - - .. attribute:: convex_hull - - The smallest convex polygon that contains this geometry, as a new - :class:`OGRGeometry` object. - - .. method:: difference - - Returns the region consisting of the difference of this geometry and - the other, as a new :class:`OGRGeometry` object. - - .. method:: intersection - - Returns the region consisting of the intersection of this geometry and - the other, as a new :class:`OGRGeometry` object. - - .. method:: sym_difference - - Returns the region consisting of the symmetric difference of this - geometry and the other, as a new :class:`OGRGeometry` object. - - .. method:: union - - Returns the region consisting of the union of this geometry and - the other, as a new :class:`OGRGeometry` object. - - .. attribute:: tuple - - Returns the coordinates of a point geometry as a tuple, the - coordinates of a line geometry as a tuple of tuples, and so forth:: - - >>> OGRGeometry('POINT (1 2)').tuple - (1.0, 2.0) - >>> OGRGeometry('LINESTRING (1 2,3 4)').tuple - ((1.0, 2.0), (3.0, 4.0)) - - .. attribute:: coords - - An alias for :attr:`tuple`. - -.. class:: Point - - .. attribute:: x - - Returns the X coordinate of this point:: - - >>> OGRGeometry('POINT (1 2)').x - 1.0 - - .. attribute:: y - - Returns the Y coordinate of this point:: - - >>> OGRGeometry('POINT (1 2)').y - 2.0 - - .. attribute:: z - - Returns the Z coordinate of this point, or ``None`` if the - the point does not have a Z coordinate:: - - >>> OGRGeometry('POINT (1 2 3)').z - 3.0 - -.. class:: LineString - - .. attribute:: x - - Returns a list of X coordinates in this line:: - - >>> OGRGeometry('LINESTRING (1 2,3 4)').x - [1.0, 3.0] - - .. attribute:: y - - Returns a list of Y coordinates in this line:: - - >>> OGRGeometry('LINESTRING (1 2,3 4)').y - [2.0, 4.0] - - .. attribute:: z - - Returns a list of Z coordinates in this line, or ``None`` if the - line does not have Z coordinates:: - - >>> OGRGeometry('LINESTRING (1 2 3,4 5 6)').z - [3.0, 6.0] - - -.. class:: Polygon - - .. attribute:: shell - - Returns the shell or exterior ring of this polygon, as a ``LinearRing`` - geometry. - - .. attribute:: exterior_ring - - An alias for :attr:`shell`. - - .. attribute:: centroid - - Returns a :class:`Point` representing the centroid of this polygon. - -.. class:: GeometryCollection - - .. method:: add(geom) - - Adds a geometry to this geometry collection. Not applicable to other - geometry types. - - -``OGRGeomType`` ---------------- - -.. class:: OGRGeomType(type_input) - - This class allows for the representation of an OGR geometry type - in any of several ways:: - - >>> from django.contrib.gis.gdal import OGRGeomType - >>> gt1 = OGRGeomType(3) # Using an integer for the type - >>> gt2 = OGRGeomType('Polygon') # Using a string - >>> gt3 = OGRGeomType('POLYGON') # It's case-insensitive - >>> print gt1 == 3, gt1 == 'Polygon' # Equivalence works w/non-OGRGeomType objects - True True - - .. attribute:: name - - Returns a short-hand string form of the OGR Geometry type:: - - >>> gt1.name - 'Polygon' - - .. attribute:: num - - Returns the number corresponding to the OGR geometry type:: - - >>> gt1.num - 3 - - .. attribute:: django - - Returns the Django field type (a subclass of GeometryField) to use for - storing this OGR type, or ``None`` if there is no appropriate Django - type:: - - >>> gt1.django - 'PolygonField' - -``Envelope`` ------------- - -.. class:: Envelope(*args) - - Represents an OGR Envelope structure that contains the - minimum and maximum X, Y coordinates for a rectangle bounding box. - The naming of the variables is compatible with the OGR Envelope - C structure. - - .. attribute:: min_x - - The value of the minimum X coordinate. - - .. attribute:: min_y - - The value of the maximum X coordinate. - - .. attribute:: max_x - - The value of the minimum Y coordinate. - - .. attribute:: max_y - - The value of the maximum Y coordinate. - - .. attribute:: ur - - The upper-right coordinate, as a tuple. - - .. attribute:: ll - - The lower-left coordinate, as a tuple. - - .. attribute:: tuple - - A tuple representing the envelope. - - .. attribute:: wkt - - A string representing this envelope as a polygon in WKT format. - - - .. method:: expand_to_include(self, *args) - - .. versionadded:: 1.1 - -Coordinate System Objects -========================= - -``SpatialReference`` --------------------- - -.. class:: SpatialReference(srs_input) - - Spatial reference objects are initialized on the given ``srs_input``, - which may be one of the following: - - * OGC Well Known Text (WKT) (a string) - * EPSG code (integer or string) - * PROJ.4 string - * A shorthand string for well-known standards (``'WGS84'``, ``'WGS72'``, ``'NAD27'``, ``'NAD83'``) - - Example:: - - >>> wgs84 = SpatialReference('WGS84') # shorthand string - >>> wgs84 = SpatialReference(4326) # EPSG code - >>> wgs84 = SpatialReference('EPSG:4326') # EPSG string - >>> proj4 = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs ' - >>> wgs84 = SpatialReference(proj4) # PROJ.4 string - >>> wgs84 = SpatialReference("""GEOGCS["WGS 84", - DATUM["WGS_1984", - SPHEROID["WGS 84",6378137,298.257223563, - AUTHORITY["EPSG","7030"]], - AUTHORITY["EPSG","6326"]], - PRIMEM["Greenwich",0, - AUTHORITY["EPSG","8901"]], - UNIT["degree",0.01745329251994328, - AUTHORITY["EPSG","9122"]], - AUTHORITY["EPSG","4326"]]""") # OGC WKT - - .. method:: __getitem__(target) - - Returns the value of the given string attribute node, ``None`` if the node - doesn't exist. Can also take a tuple as a parameter, (target, child), - where child is the index of the attribute in the WKT. For example:: - - >>> wkt = 'GEOGCS["WGS 84", DATUM["WGS_1984, ... AUTHORITY["EPSG","4326"]]') - >>> srs = SpatialReference(wkt) # could also use 'WGS84', or 4326 - >>> print srs['GEOGCS'] - WGS 84 - >>> print srs['DATUM'] - WGS_1984 - >>> print srs['AUTHORITY'] - EPSG - >>> print srs['AUTHORITY', 1] # The authority value - 4326 - >>> print srs['TOWGS84', 4] # the fourth value in this wkt - 0 - >>> print srs['UNIT|AUTHORITY'] # For the units authority, have to use the pipe symbole. - EPSG - >>> print srs['UNIT|AUTHORITY', 1] # The authority value for the untis - 9122 - - .. method:: attr_value(target, index=0) - - The attribute value for the given target node (e.g. ``'PROJCS'``). - The index keyword specifies an index of the child node to return. - - .. method:: auth_name(target) - - Returns the authority name for the given string target node. - - .. method:: auth_code(target) - - Returns the authority code for the given string target node. - - .. method:: clone() - - Returns a clone of this spatial reference object. - - .. method:: identify_epsg() - - This method inspects the WKT of this SpatialReference, and will - add EPSG authority nodes where an EPSG identifier is applicable. - - .. method:: from_esri() - - Morphs this SpatialReference from ESRI's format to EPSG - - .. method:: to_esri() - - Morphs this SpatialReference to ESRI's format. - - .. method:: validate() - - Checks to see if the given spatial reference is valid, if not - an exception will be raised. - - .. method:: import_epsg(epsg) - - Import spatial reference from EPSG code. - - .. method:: import_proj(proj) - - Import spatial reference from PROJ.4 string. - - .. method:: import_user_input(user_input) - - .. versionadded:: 1.1 - - .. method:: import_wkt(wkt) - - Import spatial reference from WKT. - - .. method:: import_xml(xml) - - Import spatial reference from XML. - - .. attribute:: name - - Returns the name of this Spatial Reference. - - .. attribute:: srid - - Returns the SRID of top-level authority, or ``None`` if undefined. - - .. attribute:: linear_name - - Returns the name of the linear units. - - .. attribute:: linear_units - - Returns the value of the linear units. - - .. attribute:: angular_name - - Returns the name of the angular units." - - .. attribute:: angular_units - - Returns the value of the angular units. - - .. attribute:: units - - Returns a 2-tuple of the units value and the units name, - and will automatically determines whether to return the linear - or angular units. - - .. attribute:: ellisoid - - Returns a tuple of the ellipsoid parameters for this spatial - reference: (semimajor axis, semiminor axis, and inverse flattening) - - .. attribute:: semi_major - - Returns the semi major axis of the ellipsoid for this spatial reference. - - .. attribute:: semi_minor - - Returns the semi minor axis of the ellipsoid for this spatial reference. - - .. attribute:: inverse_flattening - - Returns the inverse flattening of the ellipsoid for this spatial reference. - - .. attribute:: geographic - - Returns ``True`` if this spatial reference is geographic - (root node is ``GEOGCS``). - - .. attribute:: local - - Returns ``True`` if this spatial reference is local - (root node is ``LOCAL_CS``). - - .. attribute:: projected - - Returns ``True`` if this spatial reference is a projected coordinate - system (root node is ``PROJCS``). - - .. attribute:: wkt - - Returns the WKT representation of this spatial reference. - - .. attribute:: pretty_wkt - - Returns the 'pretty' representation of the WKT. - - .. attribute:: proj - - Returns the PROJ.4 representation for this spatial reference. - - .. attribute:: proj4 - - Alias for :attr:`SpatialReference.proj`. - - .. attribute:: xml - - Returns the XML representation of this spatial reference. - - -``CoordTransform`` ------------------- - -.. class:: CoordTransform(source, target) - -Represents a coordinate system transform. It is initialized with two -:class:`SpatialReference`, representing the source and target coordinate -systems, respectively. These objects should be used when performing -the same coordinate transformation repeatedly on different geometries:: - - >>> ct = CoordTransform(SpatialReference('WGS84'), SpatialReference('NAD83')) - >>> for feat in layer: - ... geom = feat.geom # getting clone of feature geometry - ... geom.transform(ct) # transforming - -Settings -======== - -.. setting:: GDAL_LIBRARY_PATH - -GDAL_LIBRARY_PATH ------------------ - -A string specifying the location of the GDAL library. Typically, -this setting is only used if the GDAL library is in a non-standard -location (e.g., ``/home/john/lib/libgdal.so``). |