TileStache.Geography | index

`The geography bits of TileStache.
A Projection defines the relationship between the rendered tiles and the
underlying geographic data. Generally, just one popular projection is used
for most web maps, "spherical mercator".
Built-in projections:
- spherical mercator
- WGS84
Example use projection in a layer definition:
"layer-name": {
"projection": "spherical mercator",
...
}
You can define your own projection, with a module and object name as arguments:
"layer-name": {
...
"projection": "Module:Object"
}
The object must include methods that convert between coordinates, points, and
locations. See the included mercator and WGS84 implementations for example.
You can also instantiate a projection class using this syntax:
"layer-name": {
...
"projection": "Module:Object()"
}`

Modules

``

TileStache.Config | TileStache.Core |  |

Classes

``

ModestMaps.Geo.LinearProjection(ModestMaps.Geo.IProjection)
  WGS84
ModestMaps.Geo.MercatorProjection(ModestMaps.Geo.IProjection)
  SphericalMercator

class SphericalMercator(ModestMaps.Geo.MercatorProjection)
`` | `Spherical mercator projection for most commonly-used web map tile scheme. This projection is identified by the name "spherical mercator" in the TileStache config. The simplified projection used here is described in greater detail at: http://trac.openlayers.org/wiki/SphericalMercator`

Method resolution order:
  SphericalMercator
  ModestMaps.Geo.MercatorProjection
  ModestMaps.Geo.IProjection

Methods defined here:

__init__(self)

coordinateProj(self, coord)
  `Convert from Coordinate object to a Point object in EPSG:900913`

locationProj(self, location)
  `Convert from Location object to a Point object in EPSG:900913`

projCoordinate(self, point)
  `Convert from Point object in EPSG:900913 to a Coordinate object`

projLocation(self, point)
  `Convert from Point object in EPSG:900913 to a Location object`

Data and other attributes defined here:

srs = '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lo...0 +units=m +nadgrids=@null +wktext +no_defs +over'

Methods inherited from ModestMaps.Geo.MercatorProjection:

rawProject(self, point)

rawUnproject(self, point)

Methods inherited from ModestMaps.Geo.IProjection:

coordinateLocation(self, coordinate)

locationCoordinate(self, location)

project(self, point)

unproject(self, point)

class WGS84(ModestMaps.Geo.LinearProjection)
`` | `Unprojected projection for the other commonly-used web map tile scheme. This projection is identified by the name "WGS84" in the TileStache config.`

Method resolution order:
  WGS84
  ModestMaps.Geo.LinearProjection
  ModestMaps.Geo.IProjection

Methods defined here:

__init__(self)

coordinateProj(self, coord)
  `Convert from Coordinate object to a Point object in EPSG:4326`

locationProj(self, location)
  `Convert from Location object to a Point object in EPSG:4326`

projCoordinate(self, point)
  `Convert from Point object in EPSG:4326 to a Coordinate object`

projLocation(self, point)
  `Convert from Point object in EPSG:4326 to a Location object`

Data and other attributes defined here:

srs = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'

Methods inherited from ModestMaps.Geo.LinearProjection:

rawProject(self, point)

rawUnproject(self, point)

Methods inherited from ModestMaps.Geo.IProjection:

coordinateLocation(self, coordinate)

locationCoordinate(self, location)

project(self, point)

unproject(self, point)

Functions

``

getProjectionByName(name)
  `Retrieve a projection object by name.
  Raise an exception if the name doesn't work out.`