Proj¶
pyproj.Proj is functionally equivalent to the proj command line tool in PROJ.
The PROJ docs say:
The `proj` program is limited to converting between geographic and
projection coordinates within one datum.
pyproj.Proj¶
-
class
pyproj.proj.
Proj
(projparams: Any = None, preserve_units: bool = True, **kwargs)[source]¶ Bases:
pyproj._proj._Proj
Performs cartographic transformations. Converts from longitude, latitude to native map projection x,y coordinates and vice versa using PROJ (https://proj.org).
-
srs
¶ The string form of the user input used to create the Proj.
- Type
str
-
crs
¶ The CRS object associated with the Proj.
- Type
-
__call__
(longitude: Any, latitude: Any, inverse: bool = False, errcheck: bool = False, radians: bool = False) → Tuple[Any, Any][source]¶ Calling a Proj class instance with the arguments lon, lat will convert lon/lat (in degrees) to x/y native map projection coordinates (in meters).
Inputs should be doubles (they will be cast to doubles if they are not, causing a slight performance hit).
Works with numpy and regular python array objects, python sequences and scalars, but is fastest for array objects.
- Parameters
longitude (scalar or array (numpy or python)) – Input longitude coordinate(s).
latitude (scalar or array (numpy or python)) – Input latitude coordinate(s).
inverse (boolean, optional) – If inverse is True the inverse transformation from x/y to lon/lat is performed. Default is False.
radians (boolean, optional) – If True, will expect input data to be in radians and will return radians if the projection is geographic. Default is False (degrees). This does not work with pyproj 2 and is ignored. It will be enabled again in pyproj 3.
errcheck (boolean, optional) – If True an exception is raised if the errors are found in the process. By default errcheck=False and
inf
is returned.
- Returns
The transformed coordinates.
- Return type
Tuple[Any, Any]
-
__init__
(projparams: Any = None, preserve_units: bool = True, **kwargs) → None[source]¶ A Proj class instance is initialized with proj map projection control parameter key/value pairs. The key/value pairs can either be passed in a dictionary, or as keyword arguments, or as a PROJ string (compatible with the proj command). See https://proj.org/operations/projections/index.html for examples of key/value pairs defining different map projections.
- Parameters
projparams (int, str, dict, pyproj.CRS) – A PROJ or WKT string, PROJ dict, EPSG integer, or a pyproj.CRS instance.
preserve_units (bool) – If false, will ensure +units=m.
**kwargs – PROJ projection parameters.
Example usage:
>>> from pyproj import Proj >>> p = Proj(proj='utm',zone=10,ellps='WGS84', preserve_units=False) >>> x,y = p(-120.108, 34.36116666) >>> 'x=%9.3f y=%11.3f' % (x,y) 'x=765975.641 y=3805993.134' >>> 'lon=%8.3f lat=%5.3f' % p(x,y,inverse=True) 'lon=-120.108 lat=34.361' >>> # do 3 cities at a time in a tuple (Fresno, LA, SF) >>> lons = (-119.72,-118.40,-122.38) >>> lats = (36.77, 33.93, 37.62 ) >>> x,y = p(lons, lats) >>> 'x: %9.3f %9.3f %9.3f' % x 'x: 792763.863 925321.537 554714.301' >>> 'y: %9.3f %9.3f %9.3f' % y 'y: 4074377.617 3763936.941 4163835.303' >>> lons, lats = p(x, y, inverse=True) # inverse transform >>> 'lons: %8.3f %8.3f %8.3f' % lons 'lons: -119.720 -118.400 -122.380' >>> 'lats: %8.3f %8.3f %8.3f' % lats 'lats: 36.770 33.930 37.620' >>> p2 = Proj('+proj=utm +zone=10 +ellps=WGS84', preserve_units=False) >>> x,y = p2(-120.108, 34.36116666) >>> 'x=%9.3f y=%11.3f' % (x,y) 'x=765975.641 y=3805993.134' >>> p = Proj("epsg:32667", preserve_units=False) >>> 'x=%12.3f y=%12.3f (meters)' % p(-114.057222, 51.045) 'x=-1783506.250 y= 6193827.033 (meters)' >>> p = Proj("epsg:32667") >>> 'x=%12.3f y=%12.3f (feet)' % p(-114.057222, 51.045) 'x=-5851386.754 y=20320914.191 (feet)' >>> # test data with radian inputs >>> p1 = Proj("epsg:4214") >>> x1, y1 = p1(116.366, 39.867) >>> '{:.3f} {:.3f}'.format(x1, y1) '116.366 39.867' >>> x2, y2 = p1(x1, y1, inverse=True) >>> '{:.3f} {:.3f}'.format(x2, y2) '116.366 39.867'
-
definition_string
() → str[source]¶ Returns formal definition string for projection
>>> Proj("epsg:4326").definition_string() 'proj=longlat datum=WGS84 no_defs ellps=WGS84 towgs84=0,0,0'
-
get_factors
(longitude: Any, latitude: Any, radians: bool = False, errcheck: bool = False) → importlib._bootstrap.Factors[source]¶ New in version 2.6.0.
Calculate various cartographic properties, such as scale factors, angular distortion and meridian convergence. Depending on the underlying projection values will be calculated either numerically (default) or analytically.
The function also calculates the partial derivatives of the given coordinate.
- Parameters
longitude (scalar or array (numpy or python)) – Input longitude coordinate(s).
latitude (scalar or array (numpy or python)) – Input latitude coordinate(s).
radians (boolean, optional) – If True, will expect input data to be in radians. Default is False (degrees).
errcheck (boolean, optional) – If True an exception is raised if the errors are found in the process. By default errcheck=False and
inf
is returned.
- Returns
- Return type
-
has_inverse
¶ Returns true if this projection has an inverse
-
is_exact_same
(self, other)¶ Compares Proj objects to see if they are exactly the same.
-
to_latlong
() → pyproj.proj.Proj[source]¶ return a new Proj instance which is the geographic (lat/lon) coordinate version of the current projection
-
pyproj.proj.Factors¶
-
class
pyproj.proj.
Factors
¶ New in version 2.6.0.
These are the scaling and angular distortion factors.
See PJ_FACTORS documentation # noqa
- Parameters
meridional_scale (List[float]) – Meridional scale at coordinate.
parallel_scale (List[float]) – Parallel scale at coordinate.
areal_scale (List[float]) – Areal scale factor at coordinate.
angular_distortion (List[float]) – Angular distortion at coordinate.
meridian_parallel_angle (List[float]) – Meridian/parallel angle at coordinate.
meridian_convergence (List[float]) – Meridian convergence at coordinate. Sometimes also described as grid declination.
tissot_semimajor (List[float]) – Maximum scale factor.
tissot_semiminor (List[float]) – Minimum scale factor.
dx_dlam (List[float]) – Partial derivative of coordinate.
dx_dphi (List[float]) – Partial derivative of coordinate.
dy_dlam (List[float]) – Partial derivative of coordinate.
dy_dphi (List[float]) – Partial derivative of coordinate.
-
property
angular_distortion
¶ Alias for field number 3
-
property
areal_scale
¶ Alias for field number 2
-
property
dx_dlam
¶ Alias for field number 8
-
property
dx_dphi
¶ Alias for field number 9
-
property
dy_dlam
¶ Alias for field number 10
-
property
dy_dphi
¶ Alias for field number 11
-
property
meridian_convergence
¶ Alias for field number 5
-
property
meridian_parallel_angle
¶ Alias for field number 4
-
property
meridional_scale
¶ Alias for field number 0
-
property
parallel_scale
¶ Alias for field number 1
-
property
tissot_semimajor
¶ Alias for field number 6
-
property
tissot_semiminor
¶ Alias for field number 7