Merge pull request SciTools#1863 from stefraynaud/decimal_point

Add cardinal_labels and decimal_point options to lon/lat formatters

lib/cartopy/mpl/geoaxes.py

@@ -1423,7 +1423,8 @@ def gridlines(self, crs=None, draw_labels=False,
                   xformatter=None, yformatter=None, xlim=None, ylim=None,
                   rotate_labels=None, xlabel_style=None, ylabel_style=None,
                   labels_bbox_style=None, xpadding=5, ypadding=5,
-                  offset_angle=25, auto_update=False, **kwargs):
+                  offset_angle=25, auto_update=False, formatter_kwargs=None,
+                  **kwargs):
         """
         Automatically add gridlines to the axes, in the given coordinate
         system, at draw time.
@@ -1530,6 +1531,10 @@ def gridlines(self, crs=None, draw_labels=False,
         auto_update: bool
             Whether to update the grilines and labels when the plot is
             refreshed.
+        formatter_kwargs: dict, optional
+            Options passed to the default formatters.
+            See :class:`~cartopy.mpl.ticker.LongitudeFormatter` and
+            :class:`~cartopy.mpl.ticker.LatitudeFormatter`
 
         Keyword Parameters
         ------------------
@@ -1563,7 +1568,7 @@ def gridlines(self, crs=None, draw_labels=False,
             xlabel_style=xlabel_style, ylabel_style=ylabel_style,
             labels_bbox_style=labels_bbox_style,
             xpadding=xpadding, ypadding=ypadding, offset_angle=offset_angle,
-            auto_update=auto_update)
+            auto_update=auto_update, formatter_kwargs=formatter_kwargs)
         self._gridliners.append(gl)
         return gl
 

lib/cartopy/mpl/gridliner.py

@@ -113,7 +113,7 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
                  xlim=None, ylim=None, rotate_labels=None,
                  xlabel_style=None, ylabel_style=None, labels_bbox_style=None,
                  xpadding=5, ypadding=5, offset_angle=25,
-                 auto_update=False):
+                 auto_update=False, formatter_kwargs=None):
         """
         Object used by :meth:`cartopy.mpl.geoaxes.GeoAxes.gridlines`
         to add gridlines and tick labels to a map.
@@ -220,6 +220,10 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
         auto_update: bool
             Whether to redraw the gridlines and labels when the figure is
             updated.
+        formatter_kwargs: dict, optional
+            Options passed to the default formatters.
+            See :class:`~cartopy.mpl.ticker.LongitudeFormatter` and
+            :class:`~cartopy.mpl.ticker.LatitudeFormatter`
 
         Notes
         -----
@@ -254,17 +258,22 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
         else:
             self.ylocator = classic_locator
 
+        formatter_kwargs = {
+            **(formatter_kwargs or {}),
+            "dms": dms,
+        }
+
         if xformatter is None:
             if isinstance(crs, PlateCarree):
-                xformatter = LongitudeFormatter(dms=dms)
+                xformatter = LongitudeFormatter(**formatter_kwargs)
             else:
                 xformatter = classic_formatter()
         #: The :class:`~matplotlib.ticker.Formatter` to use for the lon labels.
         self.xformatter = xformatter
 
         if yformatter is None:
             if isinstance(crs, PlateCarree):
-                yformatter = LatitudeFormatter(dms=dms)
+                yformatter = LatitudeFormatter(**formatter_kwargs)
             else:
                 yformatter = classic_formatter()
         #: The :class:`~matplotlib.ticker.Formatter` to use for the lat labels.

lib/cartopy/mpl/ticker.py

@@ -6,6 +6,7 @@
 """This module contains tools for handling tick marks in cartopy."""
 
 import numpy as np
+import matplotlib as mpl
 from matplotlib.ticker import Formatter, MaxNLocator
 
 import cartopy.crs as ccrs
@@ -25,7 +26,7 @@ def __init__(self, direction_label=True, degree_symbol='\u00B0',
                  number_format='g', transform_precision=1e-8, dms=False,
                  minute_symbol="'", second_symbol="''",
                  seconds_number_format='g',
-                 auto_hide=True):
+                 auto_hide=True, decimal_point=None, cardinal_labels=None):
         """
         Base class for simpler implementation of specialised formatters
         for latitude and longitude axes.
@@ -43,6 +44,14 @@ def __init__(self, direction_label=True, degree_symbol='\u00B0',
         self._auto_hide_degrees = False
         self._auto_hide_minutes = False
         self._precision = 5  # locator precision
+        if (decimal_point is None and
+                mpl.rcParams['axes.formatter.use_locale']):
+            import locale
+            decimal_point = locale.localeconv()["decimal_point"]
+        if cardinal_labels is None:
+            cardinal_labels = {}
+        self._cardinal_labels = cardinal_labels
+        self._decimal_point = decimal_point
 
     def __call__(self, value, pos=None):
         if self.axis is not None and isinstance(self.axis.axes, GeoAxes):
@@ -158,7 +167,10 @@ def _format_degrees(self, deg):
             number_format = 'd'
         else:
             number_format = self._degrees_number_format
-        return f'{abs(deg):{number_format}}{self._degree_symbol}'
+        value = f"{abs(deg):{number_format}}{self._degree_symbol}"
+        if self._decimal_point is not None:
+            value = value.replace(".", self._decimal_point)
+        return value
 
     def _format_minutes(self, mn):
         """Format minutes as an integer"""
@@ -197,6 +209,7 @@ def __init__(self, direction_label=True,
                  transform_precision=1e-8, dms=False,
                  minute_symbol="'", second_symbol="''",
                  seconds_number_format='g', auto_hide=True,
+                 decimal_point=None, cardinal_labels=None
                  ):
         """
         Tick formatter for latitudes.
@@ -237,6 +250,13 @@ def __init__(self, direction_label=True,
             values. Defaults to 'g'.
         auto_hide: bool, optional
             Auto-hide degrees or minutes when redundant.
+        decimal_point: bool, optional
+            Decimal point character. If not provided and
+            ``mpl.rcParams['axes.formatter.use_locale'] == True``,
+            the locale decimal point is used.
+        cardinal_labels: dict, optional
+            A dictionary with "south" and/or "north" keys to replace south and
+            north cardinal labels, which defaults to "S" and "N".
 
         Note
         ----
@@ -282,6 +302,8 @@ def __init__(self, direction_label=True,
             second_symbol=second_symbol,
             seconds_number_format=seconds_number_format,
             auto_hide=auto_hide,
+            decimal_point=decimal_point,
+            cardinal_labels=cardinal_labels
         )
 
     def _apply_transform(self, value, target_proj, source_crs):
@@ -290,9 +312,9 @@ def _apply_transform(self, value, target_proj, source_crs):
     def _hemisphere(self, value, value_source_crs):
 
         if value > 0:
-            hemisphere = 'N'
+            hemisphere = self._cardinal_labels.get('north', 'N')
         elif value < 0:
-            hemisphere = 'S'
+            hemisphere = self._cardinal_labels.get('south', 'S')
         else:
             hemisphere = ''
         return hemisphere
@@ -313,6 +335,8 @@ def __init__(self,
                  second_symbol="''",
                  seconds_number_format='g',
                  auto_hide=True,
+                 decimal_point=None,
+                 cardinal_labels=None
                  ):
         """
         Create a formatter for longitudes.
@@ -360,6 +384,13 @@ def __init__(self,
             values. Defaults to 'g'.
         auto_hide: bool, optional
             Auto-hide degrees or minutes when redundant.
+        decimal_point: bool, optional
+            Decimal point character. If not provided and
+            ``mpl.rcParams['axes.formatter.use_locale'] == True``,
+            the locale decimal point is used.
+        cardinal_labels: dict, optional
+            A dictionary with "west" and/or "east" keys to replace west and
+            east cardinal labels, which defaults to "W" and "E".
 
         Note
         ----
@@ -406,6 +437,8 @@ def __init__(self,
             second_symbol=second_symbol,
             seconds_number_format=seconds_number_format,
             auto_hide=auto_hide,
+            decimal_point=decimal_point,
+            cardinal_labels=cardinal_labels
         )
         self._zero_direction_labels = zero_direction_label
         self._dateline_direction_labels = dateline_direction_label
@@ -444,18 +477,18 @@ def _hemisphere(self, value, value_source_crs):
         value = self._fix_lons(value)
         # Perform basic hemisphere detection.
         if value < 0:
-            hemisphere = 'W'
+            hemisphere = self._cardinal_labels.get('west', 'W')
         elif value > 0:
-            hemisphere = 'E'
+            hemisphere = self._cardinal_labels.get('east', 'E')
         else:
             hemisphere = ''
         # Correct for user preferences:
         if value == 0 and self._zero_direction_labels:
             # Use the original tick value to determine the hemisphere.
             if value_source_crs < 0:
-                hemisphere = 'E'
+                hemisphere = self._cardinal_labels.get('east', 'E')
             else:
-                hemisphere = 'W'
+                hemisphere = self._cardinal_labels.get('west', 'W')
         if value in (-180, 180) and not self._dateline_direction_labels:
             hemisphere = ''
         return hemisphere

lib/cartopy/tests/mpl/test_gridliner.py

@@ -381,25 +381,24 @@ def test_gridliner_line_limits():
     "draw_labels, result",
     [
         (True,
-         {'left': ['70°E', '40°N'],
-          'right': ['130°E', '40°N', '50°N'],
-          'top': ['130°E', '50°N', '100°E', '70°E'],
+         {'left': ['40°N'],
+          'right': ['40°N', '50°N'],
+          'top': ['70°E', '100°E', '130°E'],
           'bottom': ['100°E']}),
         (False,
          {'left': [],
           'right': [],
           'top': [],
           'bottom': []}),
         (['top', 'left'],
-         {'left': ['70°E', '40°N'],
+         {'left': ['40°N'],
           'right': [],
-
-          'top': ['130°E', '100°E', '50°N', '70°E'],
+          'top': ['70°E', '100°E', '130°E'],
           'bottom': []}),
         ({'top': 'x', 'right': 'y'},
          {'left': [],
           'right': ['40°N', '50°N'],
-          'top': ['100°E', '130°E', '70°E'],
+          'top': ['70°E', '100°E', '130°E'],
           'bottom': []}),
         ({'left': 'x'},
          {'left': ['70°E'],
@@ -413,16 +412,28 @@ def test_gridliner_line_limits():
           'bottom': []}),
     ])
 def test_gridliner_draw_labels_param(draw_labels, result):
-    plt.figure()
+    fig = plt.figure()
     lambert_crs = ccrs.LambertConformal(central_longitude=105)
     ax = plt.axes(projection=lambert_crs)
     ax.set_extent([75, 130, 18, 54], crs=ccrs.PlateCarree())
     gl = ax.gridlines(draw_labels=draw_labels, rotate_labels=False, dms=True,
                       x_inline=False, y_inline=False)
     gl.xlocator = mticker.FixedLocator([70, 100, 130])
     gl.ylocator = mticker.FixedLocator([40, 50])
-    plt.show()
+    fig.canvas.draw()
     res = {}
     for loc in 'left', 'right', 'top', 'bottom':
         artists = getattr(gl, loc+'_label_artists')
         res[loc] = [a.get_text() for a in artists if a.get_visible()]
+    assert res == result
+
+
+def test_gridliner_formatter_kwargs():
+    fig = plt.figure()
+    ax = plt.subplot(1, 1, 1, projection=ccrs.PlateCarree())
+    ax.set_extent([-80, -40.0, 10.0, -30.0])
+    gl = ax.gridlines(draw_labels=True, dms=False,
+                      formatter_kwargs=dict(cardinal_labels={'west': 'O'}))
+    fig.canvas.draw()
+    labels = [a.get_text() for a in gl.bottom_label_artists if a.get_visible()]
+    assert labels == ['75°O', '70°O', '65°O', '60°O', '55°O', '50°O', '45°O']

lib/cartopy/tests/mpl/test_ticker.py

@@ -302,3 +302,17 @@ def test_LongitudeLocator(cls, vmin, vmax, expected):
     locator = cls(dms=True)
     result = locator.tick_values(vmin, vmax)
     np.testing.assert_allclose(result, expected)
+
+
+def test_lonlatformatter_decimal_point():
+    xticker = LongitudeFormatter(decimal_point=',', number_format='0.2f')
+    yticker = LatitudeFormatter(decimal_point=',', number_format='0.2f')
+    assert xticker(-10) == "10,00°W"
+    assert yticker(-10) == "10,00°S"
+
+
+def test_lonlatformatter_cardinal_labels():
+    xticker = LongitudeFormatter(cardinal_labels={'west': 'O'})
+    yticker = LatitudeFormatter(cardinal_labels={'south': 'South'})
+    assert xticker(-10) == "10°O"
+    assert yticker(-10) == "10°South"