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Source code for matplotlib.tight_layout

"""
This module provides 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, it 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 warnings

import matplotlib
from matplotlib.transforms import TransformedBbox, Bbox

from matplotlib.font_manager import FontProperties
rcParams = matplotlib.rcParams


def _get_left(tight_bbox, axes_bbox):
    return axes_bbox.xmin - tight_bbox.xmin


def _get_right(tight_bbox, axes_bbox):
    return tight_bbox.xmax - axes_bbox.xmax


def _get_bottom(tight_bbox, axes_bbox):
    return axes_bbox.ymin - tight_bbox.ymin


def _get_top(tight_bbox, axes_bbox):
    return tight_bbox.ymax - axes_bbox.ymax


[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. 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 if h_pad is not None: vpad_inches = h_pad * font_size_inches else: vpad_inches = pad_inches if w_pad is not None: hpad_inches = w_pad * font_size_inches else: hpad_inches = 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 if _right: margin_right = 1 - _right else: margin_right = None if _top: margin_top = 1 - _top else: margin_top = None vspaces = [[] for i in range((rows + 1) * cols)] hspaces = [[] for i in range(rows * (cols + 1))] union = Bbox.union if ax_bbox_list is None: ax_bbox_list = [] for subplots in subplot_list: ax_bbox = union([ax.get_position(original=True) for ax in subplots]) ax_bbox_list.append(ax_bbox) 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 tight_bbox_raw = union([ax.get_tightbbox(renderer) for ax in subplots if ax.get_visible()]) tight_bbox = TransformedBbox(tight_bbox_raw, fig.transFigure.inverted()) row1, col1 = divmod(num1, cols) if num2 is None: # left hspaces[row1 * (cols + 1) + col1].append( _get_left(tight_bbox, ax_bbox)) # right hspaces[row1 * (cols + 1) + (col1 + 1)].append( _get_right(tight_bbox, ax_bbox)) # top vspaces[row1 * cols + col1].append( _get_top(tight_bbox, ax_bbox)) # bottom vspaces[(row1 + 1) * cols + col1].append( _get_bottom(tight_bbox, ax_bbox)) else: row2, col2 = divmod(num2, cols) for row_i in range(row1, row2 + 1): # left hspaces[row_i * (cols + 1) + col1].append( _get_left(tight_bbox, ax_bbox)) # right hspaces[row_i * (cols + 1) + (col2 + 1)].append( _get_right(tight_bbox, ax_bbox)) for col_i in range(col1, col2 + 1): # top vspaces[row1 * cols + col_i].append( _get_top(tight_bbox, ax_bbox)) # bottom vspaces[(row2 + 1) * cols + col_i].append( _get_bottom(tight_bbox, ax_bbox)) fig_width_inch, fig_height_inch = fig.get_size_inches() # margins can be negative for axes with aspect applied. And we # append + [0] to make minimum margins 0 if not margin_left: margin_left = max([sum(s) for s in hspaces[::cols + 1]] + [0]) margin_left += pad_inches / fig_width_inch if not margin_right: margin_right = max([sum(s) for s in hspaces[cols::cols + 1]] + [0]) margin_right += pad_inches / fig_width_inch if not margin_top: margin_top = max([sum(s) for s in vspaces[:cols]] + [0]) margin_top += pad_inches / fig_height_inch if not margin_bottom: margin_bottom = max([sum(s) for s in vspaces[-cols:]] + [0]) margin_bottom += pad_inches / fig_height_inch if margin_left + margin_right >= 1: margin_left = 0.4999 margin_right = 0.4999 warnings.warn('The left and right margins cannot be made large ' 'enough to accommodate all axes decorations. ') if margin_bottom + margin_top >= 1: margin_bottom = 0.4999 margin_top = 0.4999 warnings.warn('The bottom and top margins cannot be made large ' 'enough to accommodate all axes decorations. ') kwargs = dict(left=margin_left, right=1 - margin_right, bottom=margin_bottom, top=1 - margin_top) if cols > 1: hspace = ( max(sum(s) for i in range(rows) for s in hspaces[i * (cols + 1) + 1:(i + 1) * (cols + 1) - 1]) + hpad_inches / fig_width_inch) # axes widths: h_axes = (1 - margin_right - margin_left - hspace * (cols - 1)) / cols if h_axes < 0: warnings.warn('tight_layout cannot make axes width small enough ' 'to accommodate all axes decorations') kwargs["wspace"] = 0.5 else: kwargs["wspace"] = hspace / h_axes if rows > 1: vspace = (max(sum(s) for s in vspaces[cols:-cols]) + vpad_inches / fig_height_inch) v_axes = (1 - margin_top - margin_bottom - vspace * (rows - 1)) / rows if v_axes < 0: warnings.warn('tight_layout cannot make axes height small enough ' 'to accommodate all axes decorations') kwargs["hspace"] = 0.5 else: kwargs["hspace"] = vspace / v_axes return kwargs
[docs]def get_renderer(fig): if fig._cachedRenderer: renderer = fig._cachedRenderer else: canvas = fig.canvas if canvas and hasattr(canvas, "get_renderer"): renderer = canvas.get_renderer() else: # not sure if this can happen warnings.warn("tight_layout : falling back to Agg renderer") from matplotlib.backends.backend_agg import FigureCanvasAgg canvas = FigureCanvasAgg(fig) renderer = canvas.get_renderer() return renderer
[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_inches*. 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. """ subplot_list = [] nrows_list = [] ncols_list = [] ax_bbox_list = [] subplot_dict = {} # Multiple axes can share same subplot_interface (e.g., # axes_grid1); thus we need to join them together. 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) or (mod_col != 0): raise RuntimeError("") 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) if rect 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"]) #if h_pad is None: h_pad = pad #if w_pad is None: w_pad = pad 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