fix and test map ticklabels (#47)

* fix and test map ticklabels

* fixes

* comment faulty test

* add comment on faulty test

* update code

* remove strict option

Author: mathause

mplotutils/cartopy_utils.py

@@ -1,7 +1,9 @@
+import warnings
+
 import cartopy.crs as ccrs
 import matplotlib.pyplot as plt
 import numpy as np
-import shapely.geometry as sgeom
+import shapely.geometry
 from cartopy.mpl.gridliner import LATITUDE_FORMATTER, LONGITUDE_FORMATTER
 
 from .colormaps import _get_label_attr
@@ -123,7 +125,7 @@ def ylabel_map(s, labelpad=None, size=None, weight=None, y=0.5, ax=None, **kwarg
         rotation_mode=rotation_mode,
         size=size,
         weight=weight,
-        **kwargs
+        **kwargs,
     )
 
     return h
@@ -188,7 +190,7 @@ def xlabel_map(s, labelpad=None, size=None, weight=None, x=0.5, ax=None, **kwarg
         rotation_mode=rotation_mode,
         size=size,
         weight=weight,
-        **kwargs
+        **kwargs,
     )
 
     return h
@@ -206,7 +208,7 @@ def yticklabels(
     ha="right",
     va="center",
     bbox_props=dict(ec="none", fc="none"),
-    **kwargs
+    **kwargs,
 ):
 
     """
@@ -238,18 +240,18 @@ def yticklabels(
 
     """
 
-    plt.draw()
-
     # get ax if necessary
     if ax is None:
         ax = plt.gca()
 
+    ax.figure.canvas.draw()
+
     labelpad, size, weight = _get_label_attr(labelpad, size, weight)
 
     boundary_pc = _get_boundary_platecarree(ax)
 
     # ensure labels are on rhs and not in the middle
-    if len(boundary_pc) == 1:
+    if len(boundary_pc.geoms) == 1:
         lonmin, lonmax = -180, 180
     else:
         lonmin, lonmax = 0, 360
@@ -265,7 +267,7 @@ def yticklabels(
             "WARN: no points found for ylabel\n"
             "y_lim is: {:0.2f} to {:0.2f}".format(y_lim[0], y_lim[1])
         )
-        print(msg)
+        warnings.warn(msg)
 
     # get a transform instance that mpl understands
     transform = ccrs.PlateCarree()._as_mpl_transform(ax)
@@ -281,7 +283,7 @@ def yticklabels(
         x = _determine_intersection(boundary_pc, [lonmin, y], [lonmax, y])
 
         if x.size > 0:
-            x = x[0, 0]
+            x = x[:, 0].min()
             lp = labelpad[0] + labelpad[1] * np.abs(y) / 90
 
             ax.annotate(
@@ -295,7 +297,7 @@ def yticklabels(
                 xytext=(-lp, 0),
                 textcoords="offset points",
                 bbox=bbox_props,
-                **kwargs
+                **kwargs,
             )
 
 
@@ -308,7 +310,7 @@ def xticklabels(
     ha="center",
     va="top",
     bbox_props=dict(ec="none", fc="none"),
-    **kwargs
+    **kwargs,
 ):
 
     """
@@ -340,12 +342,17 @@ def xticklabels(
 
     """
 
-    plt.draw()
-
     # get ax if necessary
     if ax is None:
         ax = plt.gca()
 
+    ax.figure.canvas.draw()
+
+    # proj = ccrs.PlateCarree()
+    # points = shapely.geometry.MultiPoint([shapely.geometry.Point(x, 0) for x in x_ticks])
+    # points = proj.project_geometry(points, proj)
+    # x_ticks = [x.x for x in points.geoms]
+
     labelpad, size, weight = _get_label_attr(labelpad, size, weight)
 
     boundary_pc = _get_boundary_platecarree(ax)
@@ -361,7 +368,7 @@ def xticklabels(
             "WARN: no points found for xlabel\n"
             "x_lim is: {:0.2f} to {:0.2f}".format(x_lim[0], x_lim[1])
         )
-        print(msg)
+        warnings.warn(msg)
 
     # get a transform instance that mpl understands
     transform = ccrs.PlateCarree()._as_mpl_transform(ax)
@@ -373,7 +380,7 @@ def xticklabels(
 
         y = _determine_intersection(boundary_pc, [x, -90], [x, 90])
         if y.size > 0:
-            y = y[0, 1]
+            y = y[:, 1].min()
 
             ax.annotate(
                 msg,
@@ -386,25 +393,42 @@ def xticklabels(
                 xytext=(0, -labelpad),
                 textcoords="offset points",
                 bbox=bbox_props,
-                **kwargs
+                **kwargs,
             )
 
 
 def _get_boundary_platecarree(ax):
     # get the bounding box of the map in lat/ lon coordinates
     # after ax._get_extent_geom
     proj = ccrs.PlateCarree()
-    boundary_poly = sgeom.Polygon(ax.outline_patch.get_path().vertices)
+    boundary_poly = shapely.geometry.Polygon(ax.spines["geo"].get_path().vertices)
     eroded_boundary = boundary_poly.buffer(-ax.projection.threshold / 100)
     boundary_pc = proj.project_geometry(eroded_boundary, ax.projection)
 
+    # boundary_pc = proj.project_geometry(boundary_poly, ax.projection)
+
     return boundary_pc
 
 
 def _determine_intersection(polygon, xy1, xy2):
 
-    p1 = sgeom.Point(xy1)
-    p2 = sgeom.Point(xy2)
-    ls = sgeom.LineString([p1, p2])
+    p1 = shapely.geometry.Point(xy1)
+    p2 = shapely.geometry.Point(xy2)
+    ls = shapely.geometry.LineString([p1, p2])
+
+    intersection = polygon.boundary.intersection(ls)
+
+    if isinstance(intersection, shapely.geometry.MultiPoint):
+        arr = np.array([x.coords for x in intersection.geoms]).squeeze()
+    elif isinstance(intersection, shapely.geometry.Point):
+        arr = np.array([intersection.coords]).squeeze()
+        arr = np.atleast_2d(arr)
+    elif isinstance(intersection, shapely.geometry.LineString):
+        if intersection.is_empty:
+            return np.array([])
+        else:
+            return np.array(intersection.coords)
+    else:
+        raise TypeError(f"Unexpected type: {type(intersection)}")
 
-    return np.asarray(polygon.boundary.intersection(ls))
+    return arr

mplotutils/tests/test_mapticklabels.py

@@ -0,0 +1,111 @@
+import sys
+
+import cartopy.crs as ccrs
+import numpy as np
+
+import mplotutils as mpu
+
+from . import subplots_context
+
+
+def test_yticklabels_robinson():
+
+    with subplots_context(subplot_kw=dict(projection=ccrs.Robinson())) as (f, ax):
+
+        ax.set_global()
+
+        lat = np.arange(-90, 91, 20)
+
+        mpu.yticklabels(lat, ax=ax, size=8)
+
+        x_pos = -179.99
+
+        # two elements are not added because they are beyond the map limits
+        lat = lat[1:-1]
+
+        # remove when dropping py 3.9
+        strict = {"strict": True} if sys.version_info >= (3, 10) else {}
+        for t, y_pos in zip(ax.texts, lat, **strict):
+
+            np.testing.assert_allclose((x_pos, y_pos), t.xy, atol=0.01)
+
+        assert ax.texts[0].get_text() == "70°S"
+        assert ax.texts[-1].get_text() == "70°N"
+
+
+def test_yticklabels_robinson_180():
+
+    proj = ccrs.Robinson(central_longitude=180)
+    with subplots_context(subplot_kw=dict(projection=proj)) as (f, ax):
+
+        ax.set_global()
+
+        lat = np.arange(-90, 91, 20)
+
+        mpu.yticklabels(lat, ax=ax, size=8)
+
+        x_pos = 0.0
+
+        # two elements are not added because they are beyond the map limits
+        lat = lat[1:-1]
+
+        # remove when dropping py 3.9
+        strict = {"strict": True} if sys.version_info >= (3, 10) else {}
+        for t, y_pos in zip(ax.texts, lat, **strict):
+
+            np.testing.assert_allclose((x_pos, y_pos), t.xy, atol=0.01)
+
+        assert ax.texts[0].get_text() == "70°S"
+        assert ax.texts[-1].get_text() == "70°N"
+
+
+def test_xticklabels_robinson():
+
+    with subplots_context(subplot_kw=dict(projection=ccrs.Robinson())) as (f, ax):
+
+        ax.set_global()
+
+        lon = np.arange(-180, 181, 60)
+
+        mpu.xticklabels(lon, ax=ax, size=8)
+
+        y_pos = -89.99
+
+        # two elements are not added because they are beyond the map limits
+        lon = lon[1:-1]
+
+        # remove when dropping py 3.9
+        strict = {"strict": True} if sys.version_info >= (3, 10) else {}
+
+        for t, x_pos in zip(ax.texts, lon, **strict):
+
+            np.testing.assert_allclose((x_pos, y_pos), t.xy, atol=0.01)
+
+        assert ax.texts[0].get_text() == "120°W"
+        assert ax.texts[-1].get_text() == "120°E"
+
+
+# TODO: https://github.com/mathause/mplotutils/issues/48
+# def test_xticklabels_robinson_180():
+
+#     proj = ccrs.Robinson(central_longitude=180)
+#     with subplots_context(subplot_kw=dict(projection=proj)) as (f, ax):
+
+#         ax.set_global()
+
+#         # lon = np.arange(-180, 181, 60)
+#         lon = np.arange(0, 360, 60)
+
+
+#         mpu.xticklabels(lon, ax=ax, size=8)
+
+#         y_pos = -89.99
+
+#         # two elements are not added because they are beyond the map limits
+#         lon = lon[1:-1]
+#         for t, x_pos in zip(ax.texts, lon, strict=True):
+
+#             np.testing.assert_allclose((x_pos, y_pos), t.xy, atol=0.01)
+
+#         assert ax.texts[0].get_text() == "60°E"
+#         assert ax.texts[-1].get_text() == "60°W"