def forward(self, lat, lon, lon0=None): # MCCABE 13
'''Forward projection, from geographic to transverse Mercator.
@arg lat: Latitude of point (C{degrees}).
@arg lon: Longitude of point (C{degrees}).
@kwarg lon0: Central meridian of the projection (C{degrees}).
@return: L{EasNorExact4Tuple}C{(easting, northing,
convergence, scale)} in C{meter}, C{meter},
C{degrees} and C{scalar}.
@see: C{void TMExact::Forward(real lon0, real lat, real lon,
real &x, real &y,
real &gamma, real &k)}.
@raise EllipticError: No convergence.
'''
lat = _fix90(lat)
lon, _ = _diff182((self._lon0 if lon0 is None else lon0), lon)
# Explicitly enforce the parity
backside = _lat = _lon = False
if not self.extendp:
if lat < 0:
_lat, lat = True, -lat
if lon < 0:
_lon, lon = True, -lon
if lon > 90:
backside = True
if lat == 0:
_lat = True
lon = 180 - lon
# u,v = coordinates for the Thompson TM, Lee 54
if lat == 90:
u, v = self._Eu.cK, 0
elif lat == 0 and lon == self._1_e_90:
u, v = 0, self._Ev.cK
else: # tau = tan(phi), taup = sinh(psi)
tau, lam = tan(radians(lat)), radians(lon)
u, v = self._zetaInv(self._E.es_taupf(tau), lam)
sncndn6 = self._sncndn6(u, v)
xi, eta, _ = self._sigma3(v, *sncndn6)
if backside:
xi = 2 * self._Eu.cE - xi
y = xi * self._k0_a
x = eta * self._k0_a
if lat == 90:
g, k = lon, self._k0
else:
g, k = self._zetaScaled(sncndn6, ll=False)
if backside:
g = 180 - g
if _lat:
y, g = -y, -g
if _lon:
x, g = -x, -g
return EasNorExact4Tuple(x, y, g, k)
def forward(self, lat, lon, lon0=0, name=NN):
'''Convert a geodetic location to east- and northing.
@arg lat: Latitude of the location (C{degrees}).
@arg lon: Longitude of the location (C{degrees}).
@kwarg lon0: Optional central meridian longitude (C{degrees}).
@kwarg name: Optional name for the location (C{str}).
@return: An L{Albers7Tuple}C{(x, y, lat, lon, gamma, scale, datum)}.
@note: The origin latitude is returned by C{property lat0}. No
false easting or northing is added. The value of B{C{lat}}
should be in the range C{[-90..90] degrees}. The returned
values C{x} and C{y} will be large but finite for points
projecting to infinity, i.e. one or both of the poles.
'''
E = self.datum.ellipsoid
s = self._sign
k0 = self._k0
n0 = self._n0
nrho0 = self._nrho0
txi0 = self._txi0
sa, ca = sincos2d(_Lat_(lat) * s)
ca = max(_EPSX, ca)
ta = sa / ca
_, sxi, txi = self._cstxif3(ta)
dq = self._qZ * _Dsn(txi, txi0, sxi, self._sxi0) * (txi - txi0)
drho = -E.a * dq / (sqrt(self._m02 - n0 * dq) + self._m0)
lon = _Lon_(lon)
if lon0:
lon, _ = _diff182(_Lon_(lon0, name=_lon0_), lon)
b = radians(lon)
th = self._k02n0 * b
sth, cth = sincos2(th) # XXX sin, cos
if n0:
x = sth / n0
y = (1 - cth if cth < 0 else sth**2 / (1 + cth)) / n0
else:
x = self._k02 * b
y = 0
t = nrho0 + n0 * drho
x = t * x / k0
y = s * (nrho0 * y - drho * cth) / k0
g = degrees360(s * th)
if t:
k0 *= t * hypot1(E.b_a * ta) / E.a
t = Albers7Tuple(x, y, lat, lon, g, k0, self.datum)
return _xnamed(t, name or self.name)