def fwd(self, lons, lats, az, dist, radians=False):
"""
forward transformation - Returns longitudes, latitudes and back
azimuths of terminus points given longitudes (lons) and
latitudes (lats) of initial points, plus forward azimuths (az)
and distances (dist).
Works with numpy and regular python array objects, python
sequences and scalars.
if radians=True, lons/lats and azimuths are radians instead of
degrees. Distances are in meters.
"""
# process inputs, making copies that support buffer API.
inx, xisfloat, xislist, xistuple = _copytobuffer(lons)
iny, yisfloat, yislist, yistuple = _copytobuffer(lats)
inz, zisfloat, zislist, zistuple = _copytobuffer(az)
ind, disfloat, dislist, distuple = _copytobuffer(dist)
# call geod_for function. inputs modified in place.
_Geod._fwd(self, inx, iny, inz, ind, radians=radians)
# if inputs were lists, tuples or floats, convert back.
outx = _convertback(xisfloat,xislist,xistuple,inx)
outy = _convertback(yisfloat,yislist,xistuple,iny)
outz = _convertback(zisfloat,zislist,zistuple,inz)
return outx, outy, outz
def npts(self, lon1, lat1, lon2, lat2, npts, radians=False):
"""
Given a single initial point and terminus point (specified by
python floats lon1,lat1 and lon2,lat2), returns a list of
longitude/latitude pairs describing npts equally spaced
intermediate points along the geodesic between the initial and
terminus points.
if radians=True, lons/lats are radians instead of degrees.
Example usage:
>>> from pyproj import Geod
>>> g = Geod(ellps='clrk66') # Use Clarke 1966 ellipsoid.
>>> # specify the lat/lons of Boston and Portland.
>>> boston_lat = 42.+(15./60.); boston_lon = -71.-(7./60.)
>>> portland_lat = 45.+(31./60.); portland_lon = -123.-(41./60.)
>>> # find ten equally spaced points between Boston and Portland.
>>> lonlats = g.npts(boston_lon,boston_lat,portland_lon,portland_lat,10)
>>> for lon,lat in lonlats: print '%6.3f %7.3f' % (lat, lon)
43.528 -75.414
44.637 -79.883
45.565 -84.512
46.299 -89.279
46.830 -94.156
47.149 -99.112
47.251 -104.106
47.136 -109.100
46.805 -114.051
46.262 -118.924
"""
lons, lats = _Geod._npts(self,lon1,lat1,lon2,lat2,npts,radians=radians)
return zip(lons, lats)
def inv(self, lons1, lats1, lons2, lats2, radians=False):
"""
inverse transformation - Returns forward and back azimuths, plus
distances between initial points (specified by lons1, lats1) and
terminus points (specified by lons2, lats2).
Works with numpy and regular python array objects, python
sequences and scalars.
if radians=True, lons/lats and azimuths are radians instead of
degrees. Distances are in meters.
"""
# process inputs, making copies that support buffer API.
inx, xisfloat, xislist, xistuple = _copytobuffer(lons1)
iny, yisfloat, yislist, yistuple = _copytobuffer(lats1)
inz, zisfloat, zislist, zistuple = _copytobuffer(lons2)
ind, disfloat, dislist, distuple = _copytobuffer(lats2)
# call geod_inv function. inputs modified in place.
_Geod._inv(self, inx, iny, inz, ind, radians=radians)
# if inputs were lists, tuples or floats, convert back.
outx = _convertback(xisfloat,xislist,xistuple,inx)
outy = _convertback(yisfloat,yislist,xistuple,iny)
outz = _convertback(zisfloat,zislist,zistuple,inz)
return outx, outy, outz
def __new__(self, initparams=None, **kwargs):
"""
initialize a Geod class instance.
Geodetic parameters for specifying the ellipsoid or sphere to
use must either be given in a dictionary 'initparams' or as
keyword arguments. Following is a list of the ellipsoids that
may be defined using the 'ellps' keyword:
MERIT a=6378137.0 rf=298.257 MERIT 1983
SGS85 a=6378136.0 rf=298.257 Soviet Geodetic System 85
GRS80 a=6378137.0 rf=298.257222101 GRS 1980(IUGG, 1980)
IAU76 a=6378140.0 rf=298.257 IAU 1976
airy a=6377563.396 b=6356256.910 Airy 1830
APL4.9 a=6378137.0. rf=298.25 Appl. Physics. 1965
NWL9D a=6378145.0. rf=298.25 Naval Weapons Lab., 1965
mod_airy a=6377340.189 b=6356034.446 Modified Airy
andrae a=6377104.43 rf=300.0 Andrae 1876 (Den., Iclnd.)
aust_SA a=6378160.0 rf=298.25 Australian Natl & S. Amer. 1969
GRS67 a=6378160.0 rf=298.2471674270 GRS 67(IUGG 1967)
bessel a=6377397.155 rf=299.1528128 Bessel 1841
bess_nam a=6377483.865 rf=299.1528128 Bessel 1841 (Namibia)
clrk66 a=6378206.4 b=6356583.8 Clarke 1866
clrk80 a=6378249.145 rf=293.4663 Clarke 1880 mod.
CPM a=6375738.7 rf=334.29 Comm. des Poids et Mesures 1799
delmbr a=6376428. rf=311.5 Delambre 1810 (Belgium)
engelis a=6378136.05 rf=298.2566 Engelis 1985
evrst30 a=6377276.345 rf=300.8017 Everest 1830
evrst48 a=6377304.063 rf=300.8017 Everest 1948
evrst56 a=6377301.243 rf=300.8017 Everest 1956
evrst69 a=6377295.664 rf=300.8017 Everest 1969
evrstSS a=6377298.556 rf=300.8017 Everest (Sabah & Sarawak)
fschr60 a=6378166. rf=298.3 Fischer (Mercury Datum) 1960
fschr60m a=6378155. rf=298.3 Modified Fischer 1960
fschr68 a=6378150. rf=298.3 Fischer 1968
helmert a=6378200. rf=298.3 Helmert 1906
hough a=6378270.0 rf=297. Hough
intl a=6378388.0 rf=297. International 1909 (Hayford)
krass a=6378245.0 rf=298.3 Krassovsky, 1942
kaula a=6378163. rf=298.24 Kaula 1961
lerch a=6378139. rf=298.257 Lerch 1979
mprts a=6397300. rf=191. Maupertius 1738
new_intl a=6378157.5 b=6356772.2 New International 1967
plessis a=6376523. b=6355863. Plessis 1817 (France)
SEasia a=6378155.0 b=6356773.3205 Southeast Asia
walbeck a=6376896.0 b=6355834.8467 Walbeck
WGS60 a=6378165.0 rf=298.3 WGS 60
WGS66 a=6378145.0 rf=298.25 WGS 66
WGS72 a=6378135.0 rf=298.26 WGS 72
WGS84 a=6378137.0 rf=298.257223563 WGS 84
sphere a=6370997.0 b=6370997.0 Normal Sphere (r=6370997)
The parameters of the ellipsoid may also be set directly using
the 'a' (semi-major or equatorial axis radius) keyword, and
any one of the following keywords: 'b' (semi-minor,
or polar axis radius), 'e' (eccentricity), 'es' (eccentricity
squared), 'f' (flattening), or 'rf' (reciprocal flattening).
See the proj documentation (http://proj.maptools.org) for more
information about specifying ellipsoid parameters (specifically,
the chapter 'Specifying the Earth's figure' in the main Proj
users manual).
Example usage:
>>> from pyproj import Geod
>>> g = Geod(ellps='clrk66') # Use Clarke 1966 ellipsoid.
>>> # specify the lat/lons of some cities.
>>> boston_lat = 42.+(15./60.); boston_lon = -71.-(7./60.)
>>> portland_lat = 45.+(31./60.); portland_lon = -123.-(41./60.)
>>> newyork_lat = 40.+(47./60.); newyork_lon = -73.-(58./60.)
>>> london_lat = 51.+(32./60.); london_lon = -(5./60.)
>>> # compute forward and back azimuths, plus distance
>>> # between Boston and Portland.
>>> az12,az21,dist = g.inv(boston_lon,boston_lat,portland_lon,portland_lat)
>>> print "%7.3f %6.3f %12.3f" % (az12,az21,dist)
-66.531 75.654 4164192.708
>>> # compute latitude, longitude and back azimuth of Portland,
>>> # given Boston lat/lon, forward azimuth and distance to Portland.
>>> endlon, endlat, backaz = g.fwd(boston_lon, boston_lat, az12, dist)
>>> print "%6.3f %6.3f %13.3f" % (endlat,endlon,backaz)
45.517 -123.683 75.654
>>> # compute the azimuths, distances from New York to several
>>> # cities (pass a list)
>>> lons1 = 3*[newyork_lon]; lats1 = 3*[newyork_lat]
>>> lons2 = [boston_lon, portland_lon, london_lon]
>>> lats2 = [boston_lat, portland_lat, london_lat]
>>> az12,az21,dist = g.inv(lons1,lats1,lons2,lats2)
>>> for faz,baz,d in zip(az12,az21,dist): print "%7.3f %7.3f %9.3f" % (faz,baz,d)
54.663 -123.448 288303.720
-65.463 79.342 4013037.318
51.254 -71.576 5579916.649
"""
# if projparams is None, use kwargs.
if initparams is None:
if len(kwargs) == 0:
raise RuntimeError('no ellipsoid control parameters specified')
else:
initparams = kwargs
# set units to meters.
if not initparams.has_key('units'):
initparams['units']='m'
elif initparams['units'] != 'm':
print 'resetting units to meters ...'
initparams['units']='m'
return _Geod.__new__(self, initparams)
