Require matplotlib >= 3.4

Matplotlib has deprecated several subplot methods that were used in the
pypfilt.plot module. This commit updates pypfilt.plot to use the new
SubPlotSpec methods.

doc/install.rst

@@ -34,5 +34,5 @@ The packages required by pypfilt_ are:
 * `h5py <http://www.h5py.org/>`__ 2.2 or newer;
 * `tomli <https://github.com/hukkin/tomli>`__ 1.2 or newer;
 * `tomli-w <https://github.com/hukkin/tomli-w>`__ 0.4 or newer; and
-* `matplotlib <http://matplotlib.org/>`__ 1.5 or newer (optional, see
+* `matplotlib <http://matplotlib.org/>`__ 3.4 or newer (optional, see
   :ref:`api_plot`).

setup.cfg

@@ -36,7 +36,7 @@ install_requires =
     tomli-w >= 0.4
 
 [options.extras_require]
-plot = matplotlib >= 1.5
+plot = matplotlib >= 3.4
 
 [options.packages.find]
 where = src

src/pypfilt/plot.py

@@ -352,29 +352,30 @@ class Grid(Plot):
                 ax.yaxis.set_ticks_position('left')
                 ax.xaxis.set_ticks_position('bottom')
                 ax.label_outer()
-                if ax.is_first_col():
+                subplot = ax.get_subplotspec()
+                if subplot.is_first_col():
                     ax.set_ylabel(self.__ylbl)
-                if ax.is_last_col():
+                if subplot.is_last_col():
                     ax2 = ax.twinx()
                     ax2.set_ylabel(_label(self.__yfac[1], yf, 'yfac'),
                                    rotation=270)
                     ax2.spines['right'].set_visible(False)
                     ax2.yaxis.set_ticks_position('none')
                     ax2.yaxis.set_ticklabels([])
-                if ax.is_last_row():
+                if subplot.is_last_row():
                     ax.set_xlabel(self.__xlbl)
-                if ax.is_first_row():
+                if subplot.is_first_row():
                     ax.set_title(_label(self.__xfac[1], xf, 'xfac'))
                 ax.xaxis.get_label().set_alpha(0)
                 ax.yaxis.get_label().set_alpha(0)
                 if hide_axes:
-                    if not ax.is_first_col():
+                    if not subplot.is_first_col():
                         ax.spines['left'].set_visible(False)
                         ax.yaxis.set_ticks_position('none')
-                    if not ax.is_last_row():
+                    if not subplot.is_last_row():
                         ax.spines['bottom'].set_visible(False)
                         ax.xaxis.set_ticks_position('none')
-                    if ax.is_last_col():
+                    if subplot.is_last_col():
                         ax2.spines['bottom'].set_visible(False)
                         ax2.spines['left'].set_visible(False)
                 yield ax, df

tox.ini

@@ -23,9 +23,9 @@ test_paths = {envsitepackagesdir}/{[base]pkg} tests/ doc/
 
 [testenv:test]
 deps =
+    .[plot]
     pytest
     pytest-cov
-    matplotlib>=1.5
 # NOTE: tox 3.18 deprecated whitelist_externals and added allowlist_externals.
 whitelist_externals =
     git