Merge pull request #2258 from rcomer/mpl3.5-min-pin

Bump minimum Matplotlib version to 3.5

.github/workflows/ci-testing.yml

@@ -33,7 +33,7 @@ jobs:
         if: matrix.python-version == '3.9' && matrix.os == 'ubuntu-latest'
         id: minimum-packages
         run: |
-          pip install cython==0.29.24 matplotlib==3.4.3 numpy==1.21 owslib==0.24.1 pyproj==3.1 scipy==1.6.3 shapely==1.7.1
+          pip install cython==0.29.24 matplotlib==3.5.3 numpy==1.21 owslib==0.24.1 pyproj==3.1 scipy==1.6.3 shapely==1.7.1
 
       - name: Coverage packages
         id: coverage

INSTALL

@@ -62,7 +62,7 @@ Further information about the required dependencies can be found here:
 **Python** 3.9 or later (https://www.python.org/)
     Python 2 support was removed in v0.19.
 
-**Matplotlib** 3.4 or later (https://matplotlib.org/)
+**Matplotlib** 3.5 or later (https://matplotlib.org/)
     Python package for 2D plotting. Python package required for any
     graphical capabilities.
 

lib/cartopy/mpl/__init__.py

@@ -9,8 +9,8 @@
 
 
 _MPL_VERSION = packaging.version.parse(matplotlib.__version__)
-_MPL_34 = _MPL_VERSION.release[:2] >= (3, 4)
 _MPL_35 = _MPL_VERSION.release[:2] >= (3, 5)
+_MPL_36 = _MPL_VERSION.release[:2] >= (3, 6)
 _MPL_38 = _MPL_VERSION.release[:2] >= (3, 8)
 
-assert _MPL_34, 'Cartopy is only supported with Matplotlib 3.4 or greater.'
+assert _MPL_35, 'Cartopy is only supported with Matplotlib 3.5 or greater.'

lib/cartopy/tests/mpl/test_crs.py

@@ -8,12 +8,12 @@
 import pytest
 
 import cartopy.crs as ccrs
-from cartopy.mpl import _MPL_35
+from cartopy.mpl import _MPL_36
 
 
 @pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(
-    filename="igh_land.png", tolerance=0.5 if _MPL_35 else 3.6)
+    filename="igh_land.png", tolerance=0.5 if _MPL_36 else 3.6)
 def test_igh_land():
     crs = ccrs.InterruptedGoodeHomolosine(emphasis="land")
     ax = plt.axes(projection=crs)
@@ -24,7 +24,7 @@ def test_igh_land():
 
 @pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename="igh_ocean.png",
-                               tolerance=0.5 if _MPL_35 else 4.5)
+                               tolerance=0.5 if _MPL_36 else 4.5)
 def test_igh_ocean():
     crs = ccrs.InterruptedGoodeHomolosine(
         central_longitude=-160, emphasis="ocean"

lib/cartopy/tests/mpl/test_gridliner.py

@@ -14,6 +14,7 @@
 from shapely.geos import geos_version
 
 import cartopy.crs as ccrs
+from cartopy.mpl import _MPL_36
 from cartopy.mpl.geoaxes import GeoAxes
 from cartopy.mpl.gridliner import (LATITUDE_FORMATTER, LONGITUDE_FORMATTER,
                                    Gridliner, classic_formatter,
@@ -497,7 +498,10 @@ def test_gridliner_title_adjust():
     plt.rcParams['axes.titley'] = None
 
     fig = plt.figure(layout='constrained')
-    fig.get_layout_engine().set(h_pad=1/8)
+    if _MPL_36:
+        fig.get_layout_engine().set(h_pad=1/8)
+    else:
+        fig.set_constrained_layout_pads(h_pad=1/8)
     for n, proj in enumerate(projs, 1):
         ax = fig.add_subplot(2, 2, n, projection=proj)
         ax.coastlines()

lib/cartopy/tests/mpl/test_mpl_integration.py

@@ -12,7 +12,7 @@
 import pytest
 
 import cartopy.crs as ccrs
-from cartopy.mpl import _MPL_35, _MPL_38
+from cartopy.mpl import _MPL_38
 
 
 @pytest.mark.natural_earth
@@ -196,8 +196,7 @@ def test_simple_global():
         id='ObliqueMercator_rotated',
     ),
 ])
-@pytest.mark.mpl_image_compare(
-    tolerance=0.5 if _MPL_35 else 0.97, style='mpl20')
+@pytest.mark.mpl_image_compare(style='mpl20')
 def test_global_map(proj):
     if isinstance(proj, tuple):
         proj, kwargs = proj
@@ -957,9 +956,7 @@ def test_barbs_1d_transformed():
 
 
 @pytest.mark.natural_earth
-@pytest.mark.mpl_image_compare(
-    filename='streamplot.png', style='mpl20',
-    tolerance=0.5 if _MPL_35 else 9.77)
+@pytest.mark.mpl_image_compare(filename='streamplot.png', style='mpl20')
 def test_streamplot():
     x = np.arange(-60, 42.5, 2.5)
     y = np.arange(30, 72.5, 2.5)