Add detail to comments in _apply_params.

Author: efiring

lib/matplotlib/axis.py

@@ -303,16 +303,19 @@ def _apply_params(self, **kw):
         newmarker = [k for k in kw if k in ['size', 'width', 'pad', 'tickdir']]
         if newmarker:
             self._size = kw.pop('size', self._size)
+            # Width could be handled outside this block, but it is
+            # convenient to leave it here.
             self._width = kw.pop('width', self._width)
             self._base_pad = kw.pop('pad', self._base_pad)
-            # apply_tickdir makes _pad and _tickmarkers
+            # apply_tickdir uses _size and _base_pad to make _pad,
+            # and also makes _tickmarkers.
             self.apply_tickdir(kw.pop('tickdir', self._tickdir))
             self.tick1line.set_marker(self._tickmarkers[0])
             self.tick2line.set_marker(self._tickmarkers[1])
             for line in (self.tick1line, self.tick2line):
                 line.set_markersize(self._size)
                 line.set_markeredgewidth(self._width)
-            # _get_text1_transform uses _pad from apply_tickdir
+            # _get_text1_transform uses _pad from apply_tickdir.
             trans = self._get_text1_transform()[0]
             self.label1.set_transform(trans)
             trans = self._get_text2_transform()[0]