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Source code for matplotlib.gridspec

: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:`` 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__)

[docs]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): """ The number of rows and number of columns of the grid need to be set. Optionally, the ratio of heights and widths of rows and columns can be specified. """ 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, )
[docs] def get_geometry(self): """ Return a tuple containing the number of rows and columns in the grid. """ return self._nrows, self._ncols
[docs] def get_subplot_params(self, figure=None, fig=None): pass
[docs] def new_subplotspec(self, loc, rowspan=1, colspan=1): """Create and return a `.SubplotSpec` instance.""" loc1, loc2 = loc subplotspec = self[loc1:loc1+rowspan, loc2:loc2+colspan] return subplotspec
[docs] def set_width_ratios(self, 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
[docs] def get_width_ratios(self): return self._col_width_ratios
[docs] def set_height_ratios(self, 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
[docs] def get_height_ratios(self): return self._row_height_ratios
[docs] def get_grid_positions(self, fig, raw=False): """ Return lists of bottom and top position of rows, left and right positions of columns. If raw=True, then these are all in units relative to the container with no margins. (used for constrained_layout). """ 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 = 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)
[docs]class GridSpec(GridSpecBase): """ Specifies the geometry of the grid that a subplot can be placed in. The location of grid is determined by similar way as the SubplotParams. """ 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): """ The number of rows and number of columns of the grid need to be set. Optionally, the subplot layout parameters (e.g., left, right, etc.) can be tuned. Parameters ---------- nrows : int Number of rows in grid. ncols : int Number or columns in grid. figure : `~.figure.Figure`, optional 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. wspace : float, optional The amount of width reserved for space between subplots, expressed as a fraction of the average axis width. hspace : float, optional The amount of height reserved for space between subplots, expressed as a fraction of the average axis height. width_ratios : length *ncols* iterable, optional Width ratios of the columns. height_ratios : length *nrows* iterable, optional Height ratios of the rows. Notes ----- See `~.figure.SubplotParams` for descriptions of the layout parameters. """ self.left = left self.bottom = bottom self.right = right = 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
[docs] def update(self, **kwargs): """ Update the current values. Values set to None use the rcParams value. """ 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)
[docs] def get_subplot_params(self, figure=None): """ Return a dictionary of subplot layout parameters. The default parameters are from rcParams unless a figure attribute is set. """ 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
[docs] def locally_modified_subplot_params(self): return [k for k in self._AllowedKeys if getattr(self, k)]
[docs] 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)
[docs]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, + '.gridspec' + layoutbox.seq_id(), artist=self)
[docs] 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)
[docs] def get_topmost_subplotspec(self): """ Return the topmost `.SubplotSpec` instance associated with the subplot. """ return self._subplot_spec.get_topmost_subplotspec()
[docs]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, + '.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
[docs] def get_gridspec(self): return self._gridspec
[docs] 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
[docs] 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
[docs] 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
[docs] 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))
[docs] 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)