add a special projection for EPSG:27572

lib/cartopy/crs.py

@@ -1815,6 +1815,59 @@ def y_limits(self):
         return self._y_limits
 
 
+class LambertZoneII(Projection):
+    """
+    Lambert zone II (extended) projection (https://epsg.io/27572).
+
+    """
+    def __init__(self):
+        proj4_params = [('proj', 'lcc'),
+                        ('lat_1', 46.8),
+                        ('lat_0', 46.8),
+                        ('lon_0', 0.0),
+                        ('k_0', 0.99987742),
+                        ('x_0', 600000.0),
+                        ('y_0', 2200000.0),
+                        ('pm', 'paris'),
+                        ('units', 'm'),
+                        ('no_defs', None)]
+
+        globe = Globe(semimajor_axis='6378249.2',
+                      semiminor_axis='6356515.0',
+                      towgs84='-168,-60,320,0,0,0,0')
+
+        super().__init__(proj4_params, globe=globe)
+
+        x0, x1, y0, y1 = [0, 1.2e6, 1.6e6, 2.7e6]
+
+        self.bounds = (x0, x1, y0, y1)
+
+        self._boundary = sgeom.LineString(
+            [(x0, y0), (x0, y1), (x1, y1), (x1, y0), (x0, y0)]
+        )
+
+        self._x_limits = [x0, x1]
+        self._y_limits = [y0, y1]
+
+        self._threshold = min(x1 - x0, y1 - y0) / 100.
+
+    @property
+    def boundary(self):
+        return self._boundary
+
+    @property
+    def x_limits(self):
+        return self._x_limits
+
+    @property
+    def y_limits(self):
+        return self._y_limits
+
+    @property
+    def threshold(self):
+        return self._threshold
+
+
 class LambertAzimuthalEqualArea(Projection):
     """
     A Lambert Azimuthal Equal-Area projection.

lib/cartopy/tests/crs/test_lambert_conformal.py

@@ -114,3 +114,29 @@ def test_single_npole(self):
         assert_array_almost_equal(n_pole_crs.y_limits,
                                   expected_y,
                                   decimal=0)
+
+
+class TestLambertZoneII:
+    def setup_class(self):
+        self.point_a = (1.4868268900254693, 48.13277955695077)
+        self.point_b = (-2.3188020040300126, 48.68412929316207)
+        self.src_crs = ccrs.PlateCarree()
+        self.nan = float('nan')
+
+    def test_default(self):
+        proj = ccrs.LambertZoneII()
+        res = proj.transform_point(*self.point_a, src_crs=self.src_crs)
+        np.testing.assert_array_almost_equal(res,
+                                             (536690.18620, 2348515.62248),
+                                             decimal=5)
+        res = proj.transform_point(*self.point_b, src_crs=self.src_crs)
+        np.testing.assert_array_almost_equal(res,
+                                             (257199.57387, 2419655.71471),
+                                             decimal=5)
+
+    def test_nan(self):
+        proj = ccrs.LambertZoneII()
+        res = proj.transform_point(0.0, float('nan'), src_crs=self.src_crs)
+        assert np.all(np.isnan(res))
+        res = proj.transform_point(float('nan'), 0.0, src_crs=self.src_crs)
+        assert np.all(np.isnan(res))

lib/cartopy/tests/mpl/test_mpl_integration.py

@@ -172,6 +172,7 @@ def test_simple_global():
     pytest.param((ccrs.InterruptedGoodeHomolosine, dict(emphasis='land')),
                  id='InterruptedGoodeHomolosine'),
     ccrs.LambertCylindrical,
+    ccrs.LambertZoneII,
     pytest.param((ccrs.Mercator, dict(min_latitude=-85, max_latitude=85)),
                  id='Mercator'),
     ccrs.Miller,