Source code for matplotlib.tight_layout
"""
Routines to adjust subplot params so that subplots are
nicely fit in the figure. In doing so, only axis labels, tick labels, axes
titles and offsetboxes that are anchored to axes are currently considered.
Internally, this module assumes that the margins (left_margin, etc.) which are
differences between ax.get_tightbbox and ax.bbox are independent of axes
position. This may fail if Axes.adjustable is datalim. Also, This will fail
for some cases (for example, left or right margin is affected by xlabel).
"""
import numpy as np
from matplotlib import cbook, rcParams
from matplotlib.font_manager import FontProperties
from matplotlib.transforms import TransformedBbox, Bbox
[docs]def auto_adjust_subplotpars(
fig, renderer, nrows_ncols, num1num2_list, subplot_list,
ax_bbox_list=None, pad=1.08, h_pad=None, w_pad=None, rect=None):
"""
Return a dict of subplot parameters to adjust spacing between subplots
or ``None`` if resulting axes would have zero height or width.
Note that this function ignores geometry information of subplot
itself, but uses what is given by the *nrows_ncols* and *num1num2_list*
parameters. Also, the results could be incorrect if some subplots have
``adjustable=datalim``.
Parameters
----------
nrows_ncols : Tuple[int, int]
Number of rows and number of columns of the grid.
num1num2_list : List[int]
List of numbers specifying the area occupied by the subplot
subplot_list : list of subplots
List of subplots that will be used to calculate optimal subplot_params.
pad : float
Padding between the figure edge and the edges of subplots, as a
fraction of the font size.
h_pad, w_pad : float
Padding (height/width) between edges of adjacent subplots, as a
fraction of the font size. Defaults to *pad*.
rect : Tuple[float, float, float, float]
[left, bottom, right, top] in normalized (0, 1) figure coordinates.
"""
rows, cols = nrows_ncols
font_size_inches = (
FontProperties(size=rcParams["font.size"]).get_size_in_points() / 72)
pad_inches = pad * font_size_inches
vpad_inches = h_pad * font_size_inches if h_pad is not None else pad_inches
hpad_inches = w_pad * font_size_inches if w_pad is not None else pad_inches
if len(num1num2_list) != len(subplot_list) or len(subplot_list) == 0:
raise ValueError
if rect is None:
margin_left = margin_bottom = margin_right = margin_top = None
else:
margin_left, margin_bottom, _right, _top = rect
margin_right = 1 - _right if _right else None
margin_top = 1 - _top if _top else None
vspaces = np.zeros((rows + 1, cols))
hspaces = np.zeros((rows, cols + 1))
if ax_bbox_list is None:
ax_bbox_list = [
Bbox.union([ax.get_position(original=True) for ax in subplots])
for subplots in subplot_list]
for subplots, ax_bbox, (num1, num2) in zip(subplot_list,
ax_bbox_list,
num1num2_list):
if all(not ax.get_visible() for ax in subplots):
continue
bb = []
for ax in subplots:
if ax.get_visible():
try:
bb += [ax.get_tightbbox(renderer, for_layout_only=True)]
except TypeError:
bb += [ax.get_tightbbox(renderer)]
tight_bbox_raw = Bbox.union(bb)
tight_bbox = TransformedBbox(tight_bbox_raw,
fig.transFigure.inverted())
row1, col1 = divmod(num1, cols)
if num2 is None:
num2 = num1
row2, col2 = divmod(num2, cols)
for row_i in range(row1, row2 + 1):
hspaces[row_i, col1] += ax_bbox.xmin - tight_bbox.xmin # left
hspaces[row_i, col2 + 1] += tight_bbox.xmax - ax_bbox.xmax # right
for col_i in range(col1, col2 + 1):
vspaces[row1, col_i] += tight_bbox.ymax - ax_bbox.ymax # top
vspaces[row2 + 1, col_i] += ax_bbox.ymin - tight_bbox.ymin # bot.
fig_width_inch, fig_height_inch = fig.get_size_inches()
# margins can be negative for axes with aspect applied, so use max(, 0) to
# make them nonnegative.
if not margin_left:
margin_left = (max(hspaces[:, 0].max(), 0)
+ pad_inches / fig_width_inch)
if not margin_right:
margin_right = (max(hspaces[:, -1].max(), 0)
+ pad_inches / fig_width_inch)
if not margin_top:
margin_top = (max(vspaces[0, :].max(), 0)
+ pad_inches / fig_height_inch)
suptitle = fig._suptitle
if suptitle and suptitle.get_in_layout():
rel_suptitle_height = fig.transFigure.inverted().transform_bbox(
suptitle.get_window_extent(renderer)).height
margin_top += rel_suptitle_height + pad_inches / fig_height_inch
if not margin_bottom:
margin_bottom = (max(vspaces[-1, :].max(), 0)
+ pad_inches / fig_height_inch)
if margin_left + margin_right >= 1:
cbook._warn_external('Tight layout not applied. The left and right '
'margins cannot be made large enough to '
'accommodate all axes decorations. ')
return None
if margin_bottom + margin_top >= 1:
cbook._warn_external('Tight layout not applied. The bottom and top '
'margins cannot be made large enough to '
'accommodate all axes decorations. ')
return None
kwargs = dict(left=margin_left,
right=1 - margin_right,
bottom=margin_bottom,
top=1 - margin_top)
if cols > 1:
hspace = hspaces[:, 1:-1].max() + hpad_inches / fig_width_inch
# axes widths:
h_axes = (1 - margin_right - margin_left - hspace * (cols - 1)) / cols
if h_axes < 0:
cbook._warn_external('Tight layout not applied. tight_layout '
'cannot make axes width small enough to '
'accommodate all axes decorations')
return None
else:
kwargs["wspace"] = hspace / h_axes
if rows > 1:
vspace = vspaces[1:-1, :].max() + vpad_inches / fig_height_inch
v_axes = (1 - margin_top - margin_bottom - vspace * (rows - 1)) / rows
if v_axes < 0:
cbook._warn_external('Tight layout not applied. tight_layout '
'cannot make axes height small enough to '
'accommodate all axes decorations')
return None
else:
kwargs["hspace"] = vspace / v_axes
return kwargs
[docs]def get_renderer(fig):
if fig._cachedRenderer:
return fig._cachedRenderer
else:
canvas = fig.canvas
if canvas and hasattr(canvas, "get_renderer"):
return canvas.get_renderer()
else:
from . import backend_bases
return backend_bases._get_renderer(fig)
[docs]def get_subplotspec_list(axes_list, grid_spec=None):
"""
Return a list of subplotspec from the given list of axes.
For an instance of axes that does not support subplotspec, None is inserted
in the list.
If grid_spec is given, None is inserted for those not from the given
grid_spec.
"""
subplotspec_list = []
for ax in axes_list:
axes_or_locator = ax.get_axes_locator()
if axes_or_locator is None:
axes_or_locator = ax
if hasattr(axes_or_locator, "get_subplotspec"):
subplotspec = axes_or_locator.get_subplotspec()
subplotspec = subplotspec.get_topmost_subplotspec()
gs = subplotspec.get_gridspec()
if grid_spec is not None:
if gs != grid_spec:
subplotspec = None
elif gs.locally_modified_subplot_params():
subplotspec = None
else:
subplotspec = None
subplotspec_list.append(subplotspec)
return subplotspec_list
[docs]def get_tight_layout_figure(fig, axes_list, subplotspec_list, renderer,
pad=1.08, h_pad=None, w_pad=None, rect=None):
"""
Return subplot parameters for tight-layouted-figure with specified padding.
Parameters
----------
fig : Figure
axes_list : list of Axes
subplotspec_list : list of `.SubplotSpec`
The subplotspecs of each axes.
renderer : renderer
pad : float
Padding between the figure edge and the edges of subplots, as a
fraction of the font size.
h_pad, w_pad : float
Padding (height/width) between edges of adjacent subplots. Defaults to
*pad*.
rect : Tuple[float, float, float, float], optional
(left, bottom, right, top) rectangle in normalized figure coordinates
that the whole subplots area (including labels) will fit into.
Defaults to using the entire figure.
Returns
-------
subplotspec or None
subplotspec kwargs to be passed to `.Figure.subplots_adjust` or
None if tight_layout could not be accomplished.
"""
subplot_list = []
nrows_list = []
ncols_list = []
ax_bbox_list = []
# Multiple axes can share same subplot_interface (e.g., axes_grid1); thus
# we need to join them together.
subplot_dict = {}
subplotspec_list2 = []
for ax, subplotspec in zip(axes_list, subplotspec_list):
if subplotspec is None:
continue
subplots = subplot_dict.setdefault(subplotspec, [])
if not subplots:
myrows, mycols, _, _ = subplotspec.get_geometry()
nrows_list.append(myrows)
ncols_list.append(mycols)
subplotspec_list2.append(subplotspec)
subplot_list.append(subplots)
ax_bbox_list.append(subplotspec.get_position(fig))
subplots.append(ax)
if len(nrows_list) == 0 or len(ncols_list) == 0:
return {}
max_nrows = max(nrows_list)
max_ncols = max(ncols_list)
num1num2_list = []
for subplotspec in subplotspec_list2:
rows, cols, num1, num2 = subplotspec.get_geometry()
div_row, mod_row = divmod(max_nrows, rows)
div_col, mod_col = divmod(max_ncols, cols)
if mod_row != 0:
cbook._warn_external('tight_layout not applied: number of rows '
'in subplot specifications must be '
'multiples of one another.')
return {}
if mod_col != 0:
cbook._warn_external('tight_layout not applied: number of '
'columns in subplot specifications must be '
'multiples of one another.')
return {}
rowNum1, colNum1 = divmod(num1, cols)
if num2 is None:
rowNum2, colNum2 = rowNum1, colNum1
else:
rowNum2, colNum2 = divmod(num2, cols)
num1num2_list.append((rowNum1 * div_row * max_ncols +
colNum1 * div_col,
((rowNum2 + 1) * div_row - 1) * max_ncols +
(colNum2 + 1) * div_col - 1))
kwargs = auto_adjust_subplotpars(fig, renderer,
nrows_ncols=(max_nrows, max_ncols),
num1num2_list=num1num2_list,
subplot_list=subplot_list,
ax_bbox_list=ax_bbox_list,
pad=pad, h_pad=h_pad, w_pad=w_pad)
# kwargs can be none if tight_layout fails...
if rect is not None and kwargs is not None:
# if rect is given, the whole subplots area (including
# labels) will fit into the rect instead of the
# figure. Note that the rect argument of
# *auto_adjust_subplotpars* specify the area that will be
# covered by the total area of axes.bbox. Thus we call
# auto_adjust_subplotpars twice, where the second run
# with adjusted rect parameters.
left, bottom, right, top = rect
if left is not None:
left += kwargs["left"]
if bottom is not None:
bottom += kwargs["bottom"]
if right is not None:
right -= (1 - kwargs["right"])
if top is not None:
top -= (1 - kwargs["top"])
kwargs = auto_adjust_subplotpars(fig, renderer,
nrows_ncols=(max_nrows, max_ncols),
num1num2_list=num1num2_list,
subplot_list=subplot_list,
ax_bbox_list=ax_bbox_list,
pad=pad, h_pad=h_pad, w_pad=w_pad,
rect=(left, bottom, right, top))
return kwargs