RSGISLib Projection Tools
Representation
- rsgislib.tools.projection.get_epsg_code_from_wkt(wkt_str: str) int
Using GDAL to return the EPSG code for inputted WKT string.
- Returns
the EPSG code.
- rsgislib.tools.projection.get_wkt_from_epsg_code(epsg_code: int) str
Using GDAL to return the WKT string for inputted EPSG Code.
- Parameters
epsg_code – integer variable of the epsg code.
- Returns
string with WKT representation of the projection.
GDAL / OSR
- rsgislib.tools.projection.get_osr_prj_obj(epsg_code: int) <osgeo.osr.SpatialReference; proxy of <Swig Object of type 'OSRSpatialReferenceShadow *' at 0x7f1e6da51950> >
A function which returns an OSR SpatialReference object for a given EPSG code.
- Parameters
epsg_code – An EPSG code for the projection. Must be an integer.
- Returns
osr.SpatialReference object.
Conversion
- rsgislib.tools.projection.degrees_to_metres(latitude: float, lon_size: float, lat_size: float) -> (<class 'float'>, <class 'float'>)
Convert pixel sizes or distances in degrees to metres.
- Parameters
latitude – latitude
lon_size – numpy array of x pixel sizes (degrees)
lat_size – numpy array of y pixel sizes (degrees)
- Returns
x_size (numpy array of x pixel sizes (m)), y_size (numpy array of y pixel sizes (m))
from rsgislib import tools x_size, y_size = tools.degrees_to_metres(52,1.0,1.0)
- rsgislib.tools.projection.metres_to_degrees(latitude: float, x_size: float, y_size: float) -> (<class 'float'>, <class 'float'>)
Convert pixel sizes or distances in metres to degrees.
- Parameters
latitude – latitude
x_size – numpy array of x pixel sizes (m)
y_size – numpy array of y pixel sizes (m)
- Returns
lon_size (numpy array of x pixel sizes (degrees)), lat_size (numpy array of y pixel sizes (degrees))
from rsgislib import tools x_size, y_size = tools.metres_to_degrees(52, 1.0, 1.0)
Numeric Representation
- rsgislib.tools.projection.get_deg_coord_as_str(lat: float, lon: float, n_chars: int = 4) str
A function which produces a string representation of the coordinate provided in degrees.
- Parameters
lat – the latitude in degrees
lon – the longitude in degrees
n_chars – the number of characters to be used for each number.
- Returns
string representation of the coordinates.
Calculation
- rsgislib.tools.projection.great_circle_distance(wgs84_p1: List[float], wgs84_p2: List[float], earth_radius=6378137.0) float
A function which calculates the great circle distance between two points provided in degrees and projected with WGS84.
- Parameters
wgs84_p1 – A point provided as a list [lon (x), lat (y)]
wgs84_p2 – A point provided as a list [lon (x), lat (y)]
earth_radius – the radius of the earth to use for the calculation. The unit of this distance will define the unit of the returned distance. The default is 6,378,137 metres and therefore the the returned distance will also be in metres. However, if 6378.137 km was passed then the returned value will be in km.
- Returns
the great circle distance between the two points.