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r"""
:mod:`~matplotlib.gridspec` contains classes that help to layout multiple
`~axes.Axes` in a grid-like pattern within a figure.
The `GridSpec` specifies the overall grid structure. Individual cells within
the grid are referenced by `SubplotSpec`\s.
See the tutorial :ref:`sphx_glr_tutorials_intermediate_gridspec.py` for a
comprehensive usage guide.
"""
import copy
import logging
import numpy as np
import matplotlib as mpl
from matplotlib import _pylab_helpers, cbook, tight_layout, rcParams
from matplotlib.transforms import Bbox
import matplotlib._layoutbox as layoutbox
_log = logging.getLogger(__name__)
class GridSpecBase:
"""
A base class of GridSpec that specifies the geometry of the grid
that a subplot will be placed.
"""
def __init__(self, nrows, ncols, height_ratios=None, width_ratios=None):
"""
Parameters
----------
nrows, ncols : int
The number of rows and columns of the grid.
width_ratios : array-like of length *ncols*, optional
Defines the relative widths of the columns. Each column gets a
relative width of ``width_ratios[i] / sum(width_ratios)``.
If not given, all columns will have the same width.
height_ratios : array-like of length *nrows*, optional
Defines the relative heights of the rows. Each column gets a
relative height of ``height_ratios[i] / sum(height_ratios)``.
If not given, all rows will have the same height.
"""
self._nrows, self._ncols = nrows, ncols
self.set_height_ratios(height_ratios)
self.set_width_ratios(width_ratios)
def __repr__(self):
height_arg = (', height_ratios=%r' % self._row_height_ratios
if self._row_height_ratios is not None else '')
width_arg = (', width_ratios=%r' % self._col_width_ratios
if self._col_width_ratios is not None else '')
return '{clsname}({nrows}, {ncols}{optionals})'.format(
clsname=self.__class__.__name__,
nrows=self._nrows,
ncols=self._ncols,
optionals=height_arg + width_arg,
)
nrows = property(lambda self: self._nrows,
doc="The number of rows in the grid.")
ncols = property(lambda self: self._ncols,
doc="The number of columns in the grid.")
def get_geometry(self):
"""
Return a tuple containing the number of rows and columns in the grid.
"""
return self._nrows, self._ncols
def get_subplot_params(self, figure=None):
# Must be implemented in subclasses
pass
def new_subplotspec(self, loc, rowspan=1, colspan=1):
"""
Create and return a `.SubplotSpec` instance.
Parameters
----------
loc : (int, int)
The position of the subplot in the grid as
``(row_index, column_index)``.
rowspan, colspan : int, default: 1
The number of rows and columns the subplot should span in the grid.
"""
loc1, loc2 = loc
subplotspec = self[loc1:loc1+rowspan, loc2:loc2+colspan]
return subplotspec
def set_width_ratios(self, width_ratios):
"""
Set the relative widths of the columns.
*width_ratios* must be of length *ncols*. Each column gets a relative
width of ``width_ratios[i] / sum(width_ratios)``.
"""
if width_ratios is not None and len(width_ratios) != self._ncols:
raise ValueError('Expected the given number of width ratios to '
'match the number of columns of the grid')
self._col_width_ratios = width_ratios
def get_width_ratios(self):
"""
Return the width ratios.
This is *None* if no width ratios have been set explicitly.
"""
return self._col_width_ratios
def set_height_ratios(self, height_ratios):
"""
Set the relative heights of the rows.
*height_ratios* must be of length *nrows*. Each row gets a relative
height of ``height_ratios[i] / sum(height_ratios)``.
"""
if height_ratios is not None and len(height_ratios) != self._nrows:
raise ValueError('Expected the given number of height ratios to '
'match the number of rows of the grid')
self._row_height_ratios = height_ratios
def get_height_ratios(self):
"""
Return the height ratios.
This is *None* if no height ratios have been set explicitly.
"""
return self._row_height_ratios
def get_grid_positions(self, fig, raw=False):
"""
Return the positions of the grid cells in figure coordinates.
Parameters
----------
fig : `~matplotlib.figure.Figure`
The figure the grid should be applied to. The subplot parameters
(margins and spacing between subplots) are taken from *fig*.
raw : bool, default: False
If *True*, the subplot parameters of the figure are not taken
into account. The grid spans the range [0, 1] in both directions
without margins and there is no space between grid cells. This is
used for constrained_layout.
Returns
-------
bottoms, tops, lefts, rights : array
The bottom, top, left, right positions of the grid cells in
figure coordinates.
"""
nrows, ncols = self.get_geometry()
if raw:
left = 0.
right = 1.
bottom = 0.
top = 1.
wspace = 0.
hspace = 0.
else:
subplot_params = self.get_subplot_params(fig)
left = subplot_params.left
right = subplot_params.right
bottom = subplot_params.bottom
top = subplot_params.top
wspace = subplot_params.wspace
hspace = subplot_params.hspace
tot_width = right - left
tot_height = top - bottom
# calculate accumulated heights of columns
cell_h = tot_height / (nrows + hspace*(nrows-1))
sep_h = hspace * cell_h
if self._row_height_ratios is not None:
norm = cell_h * nrows / sum(self._row_height_ratios)
cell_heights = [r * norm for r in self._row_height_ratios]
else:
cell_heights = [cell_h] * nrows
sep_heights = [0] + ([sep_h] * (nrows-1))
cell_hs = np.cumsum(np.column_stack([sep_heights, cell_heights]).flat)
# calculate accumulated widths of rows
cell_w = tot_width / (ncols + wspace*(ncols-1))
sep_w = wspace * cell_w
if self._col_width_ratios is not None:
norm = cell_w * ncols / sum(self._col_width_ratios)
cell_widths = [r * norm for r in self._col_width_ratios]
else:
cell_widths = [cell_w] * ncols
sep_widths = [0] + ([sep_w] * (ncols-1))
cell_ws = np.cumsum(np.column_stack([sep_widths, cell_widths]).flat)
fig_tops, fig_bottoms = (top - cell_hs).reshape((-1, 2)).T
fig_lefts, fig_rights = (left + cell_ws).reshape((-1, 2)).T
return fig_bottoms, fig_tops, fig_lefts, fig_rights
def __getitem__(self, key):
"""Create and return a `.SubplotSpec` instance."""
nrows, ncols = self.get_geometry()
def _normalize(key, size, axis): # Includes last index.
orig_key = key
if isinstance(key, slice):
start, stop, _ = key.indices(size)
if stop > start:
return start, stop - 1
raise IndexError("GridSpec slice would result in no space "
"allocated for subplot")
else:
if key < 0:
key = key + size
if 0 <= key < size:
return key, key
elif axis is not None:
raise IndexError(f"index {orig_key} is out of bounds for "
f"axis {axis} with size {size}")
else: # flat index
raise IndexError(f"index {orig_key} is out of bounds for "
f"GridSpec with size {size}")
if isinstance(key, tuple):
try:
k1, k2 = key
except ValueError:
raise ValueError("unrecognized subplot spec")
num1, num2 = np.ravel_multi_index(
[_normalize(k1, nrows, 0), _normalize(k2, ncols, 1)],
(nrows, ncols))
else: # Single key
num1, num2 = _normalize(key, nrows * ncols, None)
return SubplotSpec(self, num1, num2)
class GridSpec(GridSpecBase):
"""
A grid layout to place subplots within a figure.
The location of the grid cells is determined in a similar way to
`~.figure.SubplotParams` using *left*, *right*, *top*, *bottom*, *wspace*
and *hspace*.
"""
def __init__(self, nrows, ncols, figure=None,
left=None, bottom=None, right=None, top=None,
wspace=None, hspace=None,
width_ratios=None, height_ratios=None):
"""
Parameters
----------
nrows, ncols : int
The number of rows and columns of the grid.
figure : `~.figure.Figure`, optional
Only used for constrained layout to create a proper layoutbox.
left, right, top, bottom : float, optional
Extent of the subplots as a fraction of figure width or height.
Left cannot be larger than right, and bottom cannot be larger than
top. If not given, the values will be inferred from a figure or
rcParams at draw time. See also `GridSpec.get_subplot_params`.
wspace : float, optional
The amount of width reserved for space between subplots,
expressed as a fraction of the average axis width.
If not given, the values will be inferred from a figure or
rcParams when necessary. See also `GridSpec.get_subplot_params`.
hspace : float, optional
The amount of height reserved for space between subplots,
expressed as a fraction of the average axis height.
If not given, the values will be inferred from a figure or
rcParams when necessary. See also `GridSpec.get_subplot_params`.
width_ratios : array-like of length *ncols*, optional
Defines the relative widths of the columns. Each column gets a
relative width of ``width_ratios[i] / sum(width_ratios)``.
If not given, all columns will have the same width.
height_ratios : array-like of length *nrows*, optional
Defines the relative heights of the rows. Each column gets a
relative height of ``height_ratios[i] / sum(height_ratios)``.
If not given, all rows will have the same height.
"""
self.left = left
self.bottom = bottom
self.right = right
self.top = top
self.wspace = wspace
self.hspace = hspace
self.figure = figure
GridSpecBase.__init__(self, nrows, ncols,
width_ratios=width_ratios,
height_ratios=height_ratios)
if self.figure is None or not self.figure.get_constrained_layout():
self._layoutbox = None
else:
self.figure.init_layoutbox()
self._layoutbox = layoutbox.LayoutBox(
parent=self.figure._layoutbox,
name='gridspec' + layoutbox.seq_id(),
artist=self)
# by default the layoutbox for a gridspec will fill a figure.
# but this can change below if the gridspec is created from a
# subplotspec. (GridSpecFromSubplotSpec)
_AllowedKeys = ["left", "bottom", "right", "top", "wspace", "hspace"]
def __getstate__(self):
state = self.__dict__
try:
state.pop('_layoutbox')
except KeyError:
pass
return state
def __setstate__(self, state):
self.__dict__ = state
# layoutboxes don't survive pickling...
self._layoutbox = None
def update(self, **kwargs):
"""
Update the subplot parameters of the grid.
Parameters that are not explicitly given are not changed. Setting a
parameter to *None* resets it to :rc:`figure.subplot.*`.
Parameters
----------
left, right, top, bottom : float or None, optional
Extent of the subplots as a fraction of figure width or height.
wspace, hspace : float, optional
Spacing between the subplots as a fraction of the average subplot
width / height.
"""
for k, v in kwargs.items():
if k in self._AllowedKeys:
setattr(self, k, v)
else:
raise AttributeError(f"{k} is an unknown keyword")
for figmanager in _pylab_helpers.Gcf.figs.values():
for ax in figmanager.canvas.figure.axes:
# copied from Figure.subplots_adjust
if not isinstance(ax, mpl.axes.SubplotBase):
# Check if sharing a subplots axis
if isinstance(ax._sharex, mpl.axes.SubplotBase):
if ax._sharex.get_subplotspec().get_gridspec() == self:
ax._sharex.update_params()
ax._set_position(ax._sharex.figbox)
elif isinstance(ax._sharey, mpl.axes.SubplotBase):
if ax._sharey.get_subplotspec().get_gridspec() == self:
ax._sharey.update_params()
ax._set_position(ax._sharey.figbox)
else:
ss = ax.get_subplotspec().get_topmost_subplotspec()
if ss.get_gridspec() == self:
ax.update_params()
ax._set_position(ax.figbox)
def get_subplot_params(self, figure=None):
"""
Return the `~.SubplotParams` for the GridSpec.
In order of precedence the values are taken from
- non-*None* attributes of the GridSpec
- the provided *figure*
- :rc:`figure.subplot.*`
"""
if figure is None:
kw = {k: rcParams["figure.subplot."+k] for k in self._AllowedKeys}
subplotpars = mpl.figure.SubplotParams(**kw)
else:
subplotpars = copy.copy(figure.subplotpars)
subplotpars.update(**{k: getattr(self, k) for k in self._AllowedKeys})
return subplotpars
def locally_modified_subplot_params(self):
"""
Return a list of the names of the subplot parameters explicitly set
in the GridSpec.
This is a subset of the attributes of `.SubplotParams`.
"""
return [k for k in self._AllowedKeys if getattr(self, k)]
def tight_layout(self, figure, renderer=None,
pad=1.08, h_pad=None, w_pad=None, rect=None):
"""
Adjust subplot parameters to give specified padding.
Parameters
----------
pad : float
Padding between the figure edge and the edges of subplots, as a
fraction of the font-size.
h_pad, w_pad : float, optional
Padding (height/width) between edges of adjacent subplots.
Defaults to *pad*.
rect : tuple of 4 floats, optional
(left, bottom, right, top) rectangle in normalized figure
coordinates that the whole subplots area (including labels) will
fit into. Default is (0, 0, 1, 1).
"""
subplotspec_list = tight_layout.get_subplotspec_list(
figure.axes, grid_spec=self)
if None in subplotspec_list:
cbook._warn_external("This figure includes Axes that are not "
"compatible with tight_layout, so results "
"might be incorrect.")
if renderer is None:
renderer = tight_layout.get_renderer(figure)
kwargs = tight_layout.get_tight_layout_figure(
figure, figure.axes, subplotspec_list, renderer,
pad=pad, h_pad=h_pad, w_pad=w_pad, rect=rect)
if kwargs:
self.update(**kwargs)
class GridSpecFromSubplotSpec(GridSpecBase):
"""
GridSpec whose subplot layout parameters are inherited from the
location specified by a given SubplotSpec.
"""
def __init__(self, nrows, ncols,
subplot_spec,
wspace=None, hspace=None,
height_ratios=None, width_ratios=None):
"""
The number of rows and number of columns of the grid need to
be set. An instance of SubplotSpec is also needed to be set
from which the layout parameters will be inherited. The wspace
and hspace of the layout can be optionally specified or the
default values (from the figure or rcParams) will be used.
"""
self._wspace = wspace
self._hspace = hspace
self._subplot_spec = subplot_spec
GridSpecBase.__init__(self, nrows, ncols,
width_ratios=width_ratios,
height_ratios=height_ratios)
# do the layoutboxes
subspeclb = subplot_spec._layoutbox
if subspeclb is None:
self._layoutbox = None
else:
# OK, this is needed to divide the figure.
self._layoutbox = subspeclb.layout_from_subplotspec(
subplot_spec,
name=subspeclb.name + '.gridspec' + layoutbox.seq_id(),
artist=self)
def get_subplot_params(self, figure=None):
"""Return a dictionary of subplot layout parameters.
"""
hspace = (self._hspace if self._hspace is not None
else figure.subplotpars.hspace if figure is not None
else rcParams["figure.subplot.hspace"])
wspace = (self._wspace if self._wspace is not None
else figure.subplotpars.wspace if figure is not None
else rcParams["figure.subplot.wspace"])
figbox = self._subplot_spec.get_position(figure)
left, bottom, right, top = figbox.extents
return mpl.figure.SubplotParams(left=left, right=right,
bottom=bottom, top=top,
wspace=wspace, hspace=hspace)
def get_topmost_subplotspec(self):
"""
Return the topmost `.SubplotSpec` instance associated with the subplot.
"""
return self._subplot_spec.get_topmost_subplotspec()
class SubplotSpec:
"""
Specifies the location of a subplot in a `GridSpec`.
.. note::
Likely, you'll never instantiate a `SubplotSpec` yourself. Instead you
will typically obtain one from a `GridSpec` using item-access.
Parameters
----------
gridspec : `~matplotlib.gridspec.GridSpec`
The GridSpec, which the subplot is referencing.
num1, num2 : int
The subplot will occupy the num1-th cell of the given
gridspec. If num2 is provided, the subplot will span between
num1-th cell and num2-th cell *inclusive*.
The index starts from 0.
"""
def __init__(self, gridspec, num1, num2=None):
self._gridspec = gridspec
self.num1 = num1
self.num2 = num2
if gridspec._layoutbox is not None:
glb = gridspec._layoutbox
# So note that here we don't assign any layout yet,
# just make the layoutbox that will contain all items
# associated w/ this axis. This can include other axes like
# a colorbar or a legend.
self._layoutbox = layoutbox.LayoutBox(
parent=glb,
name=glb.name + '.ss' + layoutbox.seq_id(),
artist=self)
else:
self._layoutbox = None
# num2 is a property only to handle the case where it is None and someone
# mutates num1.
@property
def num2(self):
return self.num1 if self._num2 is None else self._num2
@num2.setter
def num2(self, value):
self._num2 = value
def __getstate__(self):
state = self.__dict__
try:
state.pop('_layoutbox')
except KeyError:
pass
return state
def __setstate__(self, state):
self.__dict__ = state
# layoutboxes don't survive pickling...
self._layoutbox = None
def get_gridspec(self):
return self._gridspec
def get_geometry(self):
"""
Return the subplot geometry as tuple ``(n_rows, n_cols, start, stop)``.
The indices *start* and *stop* define the range of the subplot within
the `GridSpec`. *stop* is inclusive (i.e. for a single cell
``start == stop``).
"""
rows, cols = self.get_gridspec().get_geometry()
return rows, cols, self.num1, self.num2
def get_rows_columns(self):
"""
Return the subplot row and column numbers as a tuple
``(n_rows, n_cols, row_start, row_stop, col_start, col_stop)``.
"""
gridspec = self.get_gridspec()
nrows, ncols = gridspec.get_geometry()
row_start, col_start = divmod(self.num1, ncols)
row_stop, col_stop = divmod(self.num2, ncols)
return nrows, ncols, row_start, row_stop, col_start, col_stop
@property
def rowspan(self):
"""The rows spanned by this subplot, as a `range` object."""
ncols = self.get_gridspec().ncols
return range(self.num1 // ncols, self.num2 // ncols + 1)
@property
def colspan(self):
"""The columns spanned by this subplot, as a `range` object."""
ncols = self.get_gridspec().ncols
return range(self.num1 % ncols, self.num2 % ncols + 1)
def get_position(self, figure, return_all=False):
"""
Update the subplot position from ``figure.subplotpars``.
"""
gridspec = self.get_gridspec()
nrows, ncols = gridspec.get_geometry()
rows, cols = np.unravel_index([self.num1, self.num2], (nrows, ncols))
fig_bottoms, fig_tops, fig_lefts, fig_rights = \
gridspec.get_grid_positions(figure)
fig_bottom = fig_bottoms[rows].min()
fig_top = fig_tops[rows].max()
fig_left = fig_lefts[cols].min()
fig_right = fig_rights[cols].max()
figbox = Bbox.from_extents(fig_left, fig_bottom, fig_right, fig_top)
if return_all:
return figbox, rows[0], cols[0], nrows, ncols
else:
return figbox
def get_topmost_subplotspec(self):
"""
Return the topmost `SubplotSpec` instance associated with the subplot.
"""
gridspec = self.get_gridspec()
if hasattr(gridspec, "get_topmost_subplotspec"):
return gridspec.get_topmost_subplotspec()
else:
return self
def __eq__(self, other):
"""
Two SubplotSpecs are considered equal if they refer to the same
position(s) in the same `GridSpec`.
"""
# other may not even have the attributes we are checking.
return ((self._gridspec, self.num1, self.num2)
== (getattr(other, "_gridspec", object()),
getattr(other, "num1", object()),
getattr(other, "num2", object())))
def __hash__(self):
return hash((self._gridspec, self.num1, self.num2))
def subgridspec(self, nrows, ncols, **kwargs):
"""
Create a GridSpec within this subplot.
The created `.GridSpecFromSubplotSpec` will have this `SubplotSpec` as
a parent.
Parameters
----------
nrows : int
Number of rows in grid.
ncols : int
Number or columns in grid.
Returns
-------
gridspec : `.GridSpecFromSubplotSpec`
Other Parameters
----------------
**kwargs
All other parameters are passed to `.GridSpecFromSubplotSpec`.
See Also
--------
matplotlib.pyplot.subplots
Examples
--------
Adding three subplots in the space occupied by a single subplot::
fig = plt.figure()
gs0 = fig.add_gridspec(3, 1)
ax1 = fig.add_subplot(gs0[0])
ax2 = fig.add_subplot(gs0[1])
gssub = gs0[2].subgridspec(1, 3)
for i in range(3):
fig.add_subplot(gssub[0, i])
"""
return GridSpecFromSubplotSpec(nrows, ncols, self, **kwargs)