Dedupe SubplotSpec construction in mpl_toolkits.

i.e. parsing subplot(i, j, k) and subplot(ijk); this is done by reusing
the implementation in subplot().

Also delete some commented-out code which is clearly handled by gridspec
now.

Author: anntzer

lib/matplotlib/axes/_subplots.py

@@ -33,45 +33,8 @@ def __init__(self, fig, *args, **kwargs):
         """
 
         self.figure = fig
-
-        if len(args) == 1:
-            if isinstance(args[0], SubplotSpec):
-                self._subplotspec = args[0]
-            else:
-                try:
-                    s = str(int(args[0]))
-                    rows, cols, num = map(int, s)
-                except ValueError:
-                    raise ValueError('Single argument to subplot must be '
-                        'a 3-digit integer')
-                self._subplotspec = GridSpec(rows, cols,
-                                             figure=self.figure)[num - 1]
-                # num - 1 for converting from MATLAB to python indexing
-        elif len(args) == 3:
-            rows, cols, num = args
-            rows = int(rows)
-            cols = int(cols)
-            if rows <= 0:
-                raise ValueError(f'Number of rows must be > 0, not {rows}')
-            if cols <= 0:
-                raise ValueError(f'Number of columns must be > 0, not {cols}')
-            if isinstance(num, tuple) and len(num) == 2:
-                num = [int(n) for n in num]
-                self._subplotspec = GridSpec(
-                        rows, cols,
-                        figure=self.figure)[(num[0] - 1):num[1]]
-            else:
-                if num < 1 or num > rows*cols:
-                    raise ValueError(
-                        f"num must be 1 <= num <= {rows*cols}, not {num}")
-                self._subplotspec = GridSpec(
-                        rows, cols, figure=self.figure)[int(num) - 1]
-                # num - 1 for converting from MATLAB to python indexing
-        else:
-            raise ValueError(f'Illegal argument(s) to subplot: {args}')
-
+        self._subplotspec = SubplotSpec._from_subplot_args(fig, args)
         self.update_params()
-
         # _axes_class is set in the subplot_class_factory
         self._axes_class.__init__(self, fig, self.figbox, **kwargs)
         # add a layout box to this, for both the full axis, and the poss

lib/matplotlib/gridspec.py

@@ -522,6 +522,47 @@ def __init__(self, gridspec, num1, num2=None):
         else:
             self._layoutbox = None
 
+    @staticmethod
+    def _from_subplot_args(figure, args):
+        """
+        Construct a `.SubplotSpec` from a parent `.Figure` and either
+
+        - a `.SubplotSpec` -- returned as is;
+        - one or three numbers -- a MATLAB-style subplot specifier.
+        """
+        if len(args) == 1:
+            arg, = args
+            if isinstance(arg, SubplotSpec):
+                return arg
+            else:
+                try:
+                    s = str(int(arg))
+                    rows, cols, num = map(int, s)
+                except ValueError:
+                    raise ValueError("Single argument to subplot must be a "
+                                     "3-digit integer")
+                # num - 1 for converting from MATLAB to python indexing
+                return GridSpec(rows, cols, figure=figure)[num - 1]
+        elif len(args) == 3:
+            rows, cols, num = args
+            rows = int(rows)
+            cols = int(cols)
+            if rows <= 0:
+                raise ValueError(f"Number of rows must be > 0, not {rows}")
+            if cols <= 0:
+                raise ValueError(f"Number of columns must be > 0, not {cols}")
+            if isinstance(num, tuple) and len(num) == 2:
+                i, j = map(int, num)
+                return GridSpec(rows, cols, figure=figure)[i-1:j]
+            else:
+                if num < 1 or num > rows*cols:
+                    raise ValueError(
+                        f"num must be 1 <= num <= {rows*cols}, not {num}")
+                # num - 1 for converting from MATLAB to python indexing
+                return GridSpec(rows, cols, figure=figure)[int(num) - 1]
+        else:
+            raise ValueError(f"Illegal argument(s) to subplot: {args}")
+
     # num2 is a property only to handle the case where it is None and someone
     # mutates num1.
 

lib/mpl_toolkits/axes_grid1/axes_divider.py

@@ -10,6 +10,8 @@
     object that can be used to set the axes_locator of the axes.
 """
 
+import numpy as np
+
 from matplotlib import cbook
 from matplotlib.axes import SubplotBase
 from matplotlib.gridspec import SubplotSpec, GridSpec
@@ -274,10 +276,7 @@ def append_size(self, position, size):
             cbook._check_in_list(["left", "right", "bottom", "top"],
                                  position=position)
 
-    def add_auto_adjustable_area(self,
-                                 use_axes, pad=0.1,
-                                 adjust_dirs=None,
-                                 ):
+    def add_auto_adjustable_area(self, use_axes, pad=0.1, adjust_dirs=None):
         if adjust_dirs is None:
             adjust_dirs = ["left", "right", "bottom", "top"]
         from .axes_size import Padded, SizeFromFunc, GetExtentHelper
@@ -362,90 +361,18 @@ def __init__(self, fig, *args, horizontal=None, vertical=None,
             *args* can be passed as a single 3-digit number (e.g. 234 for
             (2, 3, 4)).
         """
-
         self.figure = fig
-
-        if len(args) == 1:
-            if isinstance(args[0], SubplotSpec):
-                self._subplotspec = args[0]
-            else:
-                try:
-                    s = str(int(args[0]))
-                    rows, cols, num = map(int, s)
-                except ValueError:
-                    raise ValueError(
-                        'Single argument to subplot must be a 3-digit integer')
-                self._subplotspec = GridSpec(rows, cols)[num-1]
-                # num - 1 for converting from MATLAB to python indexing
-        elif len(args) == 3:
-            rows, cols, num = args
-            rows = int(rows)
-            cols = int(cols)
-            if isinstance(num, tuple) and len(num) == 2:
-                num = [int(n) for n in num]
-                self._subplotspec = GridSpec(rows, cols)[num[0]-1:num[1]]
-            else:
-                self._subplotspec = GridSpec(rows, cols)[int(num)-1]
-                # num - 1 for converting from MATLAB to python indexing
-        else:
-            raise ValueError(f'Illegal argument(s) to subplot: {args}')
-
-        # total = rows*cols
-        # num -= 1    # convert from matlab to python indexing
-        #             # i.e., num in range(0, total)
-        # if num >= total:
-        #     raise ValueError( 'Subplot number exceeds total subplots')
-        # self._rows = rows
-        # self._cols = cols
-        # self._num = num
-
-        # self.update_params()
-
-        # sets self.fixbox
-        self.update_params()
-
-        pos = self.figbox.bounds
-
-        Divider.__init__(self, fig, pos, horizontal or [], vertical or [],
+        self._subplotspec = SubplotSpec._from_subplot_args(fig, args)
+        self.update_params()  # sets self.figbox
+        Divider.__init__(self, fig, pos=self.figbox.bounds,
+                         horizontal=horizontal or [], vertical=vertical or [],
                          aspect=aspect, anchor=anchor)
 
     def get_position(self):
         "return the bounds of the subplot box"
-
         self.update_params()  # update self.figbox
         return self.figbox.bounds
 
-    # def update_params(self):
-    #     'update the subplot position from fig.subplotpars'
-
-    #     rows = self._rows
-    #     cols = self._cols
-    #     num = self._num
-
-    #     pars = self.figure.subplotpars
-    #     left = pars.left
-    #     right = pars.right
-    #     bottom = pars.bottom
-    #     top = pars.top
-    #     wspace = pars.wspace
-    #     hspace = pars.hspace
-    #     totWidth = right-left
-    #     totHeight = top-bottom
-
-    #     figH = totHeight/(rows + hspace*(rows-1))
-    #     sepH = hspace*figH
-
-    #     figW = totWidth/(cols + wspace*(cols-1))
-    #     sepW = wspace*figW
-
-    #     rowNum, colNum =  divmod(num, cols)
-
-    #     figBottom = top - (rowNum+1)*figH - rowNum*sepH
-    #     figLeft = left + colNum*(figW + sepW)
-
-    #     self.figbox = mtransforms.Bbox.from_bounds(figLeft, figBottom,
-    #                                                figW, figH)
-
     def update_params(self):
         """Update the subplot position from fig.subplotpars."""
         self.figbox = self.get_subplotspec().get_position(self.figure)
@@ -664,16 +591,12 @@ def get_subplotspec(self):
 
 class HBoxDivider(SubplotDivider):
 
-    def __init__(self, fig, *args, **kwargs):
-        SubplotDivider.__init__(self, fig, *args, **kwargs)
-
     @staticmethod
     def _determine_karray(equivalent_sizes, appended_sizes,
                           max_equivalent_size,
                           total_appended_size):
 
         n = len(equivalent_sizes)
-        import numpy as np
         A = np.mat(np.zeros((n+1, n+1), dtype="d"))
         B = np.zeros((n+1), dtype="d")
         # AxK = B