示例#1
0
    def rescale0(self, lat, scale0=_K0):
        '''Set the central scale factor for this UPS projection.

           @param lat: Northern latitude (C{degrees}).
           @param scale0: UPS k0 scale at B{C{lat}} latitude (C{scalar}).

           @raise RangeError: If B{C{lat}} outside the valid range
                              and L{rangerrors} set to C{True}.

           @raise ValueError: Invalid B{C{scale}}.
        '''
        try:
            s0 = float(scale0)
            if not 0 < s0:  # <= 1.003 or 1.0016?
                raise ValueError
        except (TypeError, ValueError):
            raise ValueError('%s invalid: %r' % ('scale', scale0))

        lat = clipDMS(lat, 90)  # clip and force N
        u = toUps8(abs(lat), 0, datum=self.datum, Ups=_UpsK1)
        k = s0 / u.scale
        if self.scale0 != k:
            self._band = ''  # force re-compute
            self._latlon = self._epsg = self._mgrs = self._utm = None
            self._scale0 = k
示例#2
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def toWm(latlon, lon=None, radius=R_MA, Wm=Wm, name=''):
    '''Convert a lat-/longitude point to a WM coordinate.

       @param latlon: Latitude (C{degrees}) or an (ellipsoidal or
                      spherical) geodetic C{LatLon} point.
       @keyword lon: Optional longitude (C{degrees} or C{None}).
       @keyword radius: Optional earth radius (C{meter}).
       @keyword Wm: Optional (sub-)class to return the WM coordinate
                    (L{Wm}) or C{None}.
       @keyword name: Optional name (C{str}).

       @return: The WM coordinate (B{C{Wm}}) or an
                L{EasNorRadius3Tuple}C{(easting, northing, radius)}
                if B{C{Wm}} is C{None}.

       @raise ValueError: If B{C{lon}} value is missing, if B{C{latlon}}
                          is not scalar, if B{C{latlon}} is beyond the
                          valid WM range and L{rangerrors} is set
                          to C{True} or if B{C{radius}} is invalid.

       @example:

       >>> p = LatLon(48.8582, 2.2945)  # 448251.8 5411932.7
       >>> w = toWm(p)  # 448252 5411933
       >>> p = LatLon(13.4125, 103.8667)  # 377302.4 1483034.8
       >>> w = toWm(p)  # 377302 1483035
    '''
    r, e = radius, None
    try:
        lat, lon = latlon.lat, latlon.lon
        if isinstance(latlon, _LLEB):
            r = latlon.datum.ellipsoid.a
            e = latlon.datum.ellipsoid.e
            if not name:  # use latlon.name
                name = nameof(latlon)
        lat = clipDMS(lat, _LatLimit)
    except AttributeError:
        lat, lon = parseDMS2(latlon, lon, clipLat=_LatLimit)

    s = sin(radians(lat))
    y = atanh(s)  # == log(tan((90 + lat) / 2)) == log(tanPI_2_2(radians(lat)))
    if e:
        y -= e * atanh(e * s)

    e, n = r * radians(lon), r * y
    r = EasNorRadius3Tuple(e, n, r) if Wm is None else \
                        Wm(e, n, radius=r)
    return _xnamed(r, name)
示例#3
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def degrees2m(deg, radius=R_M, lat=0):
    '''Convert angle to distance along the equator or along a
       parallel at an other latitude.

       @param deg: Angle (C{degrees}).
       @keyword radius: Mean earth radius (C{meter}).
       @keyword lat: Parallel latitude (C{degrees90}).

       @return: Distance (C{meter}, same units as B{C{radius}}).

       @raise RangeError: Latitude B{C{lat}} outside valid range
                          and L{rangerrors} set to C{True}.
    '''
    m = radians(deg) * radius
    if lat:
        from pygeodesy.dms import clipDMS
        m *= cos(radians(clipDMS(lat, 90)))
    return m