import collections import numpy as np import numbers import warnings import matplotlib.docstring as docstring import matplotlib.ticker as mticker import matplotlib.transforms as mtransforms import matplotlib.scale as mscale import matplotlib.cbook as cbook from matplotlib.axes._base import _AxesBase from matplotlib.ticker import ( AutoLocator, AutoMinorLocator, FixedLocator, FuncFormatter, LogFormatterSciNotation, LogLocator, NullLocator, NullFormatter, ScalarFormatter ) from matplotlib.scale import Log10Transform def _make_secondary_locator(rect, parent): """ Helper function to locate the secondary axes. A locator gets used in `Axes.set_aspect` to override the default locations... It is a function that takes an axes object and a renderer and tells `set_aspect` where it is to be placed. This locator make the transform be in axes-relative co-coordinates because that is how we specify the "location" of the secondary axes. Here *rect* is a rectangle [l, b, w, h] that specifies the location for the axes in the transform given by *trans* on the *parent*. """ _rect = mtransforms.Bbox.from_bounds(*rect) def secondary_locator(ax, renderer): # delay evaluating transform until draw time because the # parent transform may have changed (i.e. if window reesized) bb = mtransforms.TransformedBbox(_rect, parent.transAxes) tr = parent.figure.transFigure.inverted() bb = mtransforms.TransformedBbox(bb, tr) return bb return secondary_locator class SecondaryAxis(_AxesBase): """ General class to hold a Secondary_X/Yaxis. """ def __init__(self, parent, orientation, location, functions, **kwargs): """ See `.secondary_xaxis` and `.secondary_yaxis` for the doc string. While there is no need for this to be private, it should really be called by those higher level functions. """ self._functions = functions self._parent = parent self._orientation = orientation self._ticks_set = False if self._orientation == 'x': super().__init__(self._parent.figure, [0, 1., 1, 0.0001], **kwargs) self._axis = self.xaxis self._locstrings = ['top', 'bottom'] self._otherstrings = ['left', 'right'] elif self._orientation == 'y': super().__init__(self._parent.figure, [0, 1., 0.0001, 1], **kwargs) self._axis = self.yaxis self._locstrings = ['right', 'left'] self._otherstrings = ['top', 'bottom'] # this gets positioned w/o constrained_layout so exclude: self._layoutbox = None self._poslayoutbox = None self.set_location(location) self.set_functions(functions) # styling: if self._orientation == 'x': otheraxis = self.yaxis else: otheraxis = self.xaxis otheraxis.set_major_locator(mticker.NullLocator()) otheraxis.set_ticks_position('none') for st in self._otherstrings: self.spines[st].set_visible(False) for st in self._locstrings: self.spines[st].set_visible(True) if self._pos < 0.5: # flip the location strings... self._locstrings = self._locstrings[::-1] self.set_alignment(self._locstrings[0]) def set_alignment(self, align): """ Set if axes spine and labels are drawn at top or bottom (or left/right) of the axes. Parameters ---------- align :: string either 'top' or 'bottom' for orientation='x' or 'left' or 'right' for orientation='y' axis """ if align in self._locstrings: if align == self._locstrings[1]: # need to change the orientation. self._locstrings = self._locstrings[::-1] elif align != self._locstrings[0]: raise ValueError('"{}" is not a valid axis orientation, ' 'not changing the orientation;' 'choose "{}" or "{}""'.format(align, self._locstrings[0], self._locstrings[1])) self.spines[self._locstrings[0]].set_visible(True) self.spines[self._locstrings[1]].set_visible(False) self._axis.set_ticks_position(align) self._axis.set_label_position(align) def set_location(self, location): """ Set the vertical or horizontal location of the axes in parent-normalized co-ordinates. Parameters ---------- location : string or scalar The position to put the secondary axis. Strings can be 'top' or 'bottom' for orientation='x' and 'right' or 'left' for orientation='y', scalar can be a float indicating the relative position on the parent axes to put the new axes, 0.0 being the bottom (or left) and 1.0 being the top (or right). """ # This puts the rectangle into figure-relative coordinates. if isinstance(location, str): if location in ['top', 'right']: self._pos = 1. elif location in ['bottom', 'left']: self._pos = 0. else: raise ValueError("location must be '{}', '{}', or a " "float, not '{}'".format(location, self._locstrings[0], self._locstrings[1])) else: self._pos = location self._loc = location if self._orientation == 'x': bounds = [0, self._pos, 1., 1e-10] else: bounds = [self._pos, 0, 1e-10, 1] secondary_locator = _make_secondary_locator(bounds, self._parent) # this locator lets the axes move in the parent axes coordinates. # so it never needs to know where the parent is explicitly in # figure co-ordinates. # it gets called in `ax.apply_aspect() (of all places) self.set_axes_locator(secondary_locator) def apply_aspect(self, position=None): self._set_lims() super().apply_aspect(position) def set_ticks(self, ticks, minor=False): """ Set the x ticks with list of *ticks* Parameters ---------- ticks : list List of x-axis tick locations. minor : bool, optional If ``False`` sets major ticks, if ``True`` sets minor ticks. Default is ``False``. """ ret = self._axis.set_ticks(ticks, minor=minor) self.stale = True self._ticks_set = True return ret def set_functions(self, functions): """ Set how the secondary axis converts limits from the parent axes. Parameters ---------- functions : 2-tuple of func, or `Transform` with an inverse. Transform between the parent axis values and the secondary axis values. If supplied as a 2-tuple of functions, the first function is the forward transform function and the second is the inverse transform. If a transform is supplied, then the transform must have an inverse. """ if self._orientation == 'x': set_scale = self.set_xscale parent_scale = self._parent.get_xscale() else: set_scale = self.set_yscale parent_scale = self._parent.get_yscale() # we need to use a modified scale so the scale can receive the # transform. Only types supported are linear and log10 for now. # Probably possible to add other transforms as a todo... if parent_scale == 'log': defscale = 'functionlog' else: defscale = 'function' if (isinstance(functions, tuple) and len(functions) == 2 and callable(functions[0]) and callable(functions[1])): # make an arbitrary convert from a two-tuple of functions # forward and inverse. self._functions = functions elif functions is None: self._functions = (lambda x: x, lambda x: x) else: raise ValueError('functions argument of secondary axes ' 'must be a two-tuple of callable functions ' 'with the first function being the transform ' 'and the second being the inverse') # need to invert the roles here for the ticks to line up. set_scale(defscale, functions=self._functions[::-1]) def draw(self, renderer=None, inframe=False): """ Draw the secondary axes. Consults the parent axes for its limits and converts them using the converter specified by `~.axes._secondary_axes.set_functions` (or *functions* parameter when axes initialized.) """ self._set_lims() # this sets the scale in case the parent has set its scale. self._set_scale() super().draw(renderer=renderer, inframe=inframe) def _set_scale(self): """ Check if parent has set its scale """ if self._orientation == 'x': pscale = self._parent.xaxis.get_scale() set_scale = self.set_xscale if self._orientation == 'y': pscale = self._parent.yaxis.get_scale() set_scale = self.set_yscale if pscale == 'log': defscale = 'functionlog' else: defscale = 'function' if self._ticks_set: ticks = self._axis.get_ticklocs() # need to invert the roles here for the ticks to line up. set_scale(defscale, functions=self._functions[::-1]) # OK, set_scale sets the locators, but if we've called # axsecond.set_ticks, we want to keep those. if self._ticks_set: self._axis.set_major_locator(FixedLocator(ticks)) def _set_lims(self): """ Set the limits based on parent limits and the convert method between the parent and this secondary axes """ if self._orientation == 'x': lims = self._parent.get_xlim() set_lim = self.set_xlim trans = self.xaxis.get_transform() if self._orientation == 'y': lims = self._parent.get_ylim() set_lim = self.set_ylim trans = self.yaxis.get_transform() order = lims[0] < lims[1] lims = self._functions[0](np.array(lims)) neworder = lims[0] < lims[1] if neworder != order: # flip because the transform will take care of the flipping.. lims = lims[::-1] set_lim(lims) def get_tightbbox(self, renderer, call_axes_locator=True): """ Return the tight bounding box of the axes. The dimension of the Bbox in canvas coordinate. If *call_axes_locator* is *False*, it does not call the _axes_locator attribute, which is necessary to get the correct bounding box. ``call_axes_locator==False`` can be used if the caller is only intereted in the relative size of the tightbbox compared to the axes bbox. """ bb = [] if not self.get_visible(): return None self._set_lims() locator = self.get_axes_locator() if locator and call_axes_locator: pos = locator(self, renderer) self.apply_aspect(pos) else: self.apply_aspect() if self._orientation == 'x': bb_axis = self.xaxis.get_tightbbox(renderer) else: bb_axis = self.yaxis.get_tightbbox(renderer) if bb_axis: bb.append(bb_axis) bb.append(self.get_window_extent(renderer)) _bbox = mtransforms.Bbox.union( [b for b in bb if b.width != 0 or b.height != 0]) return _bbox def set_aspect(self, *args, **kwargs): """ Secondary axes cannot set the aspect ratio, so calling this just sets a warning. """ cbook._warn_external("Secondary axes can't set the aspect ratio") def set_xlabel(self, xlabel, fontdict=None, labelpad=None, **kwargs): """ Set the label for the x-axis. Parameters ---------- xlabel : str The label text. labelpad : scalar, optional, default: None Spacing in points between the label and the x-axis. Other Parameters ---------------- **kwargs : `.Text` properties `.Text` properties control the appearance of the label. See also -------- text : for information on how override and the optional args work """ if labelpad is not None: self.xaxis.labelpad = labelpad return self.xaxis.set_label_text(xlabel, fontdict, **kwargs) def set_ylabel(self, ylabel, fontdict=None, labelpad=None, **kwargs): """ Set the label for the x-axis. Parameters ---------- ylabel : str The label text. labelpad : scalar, optional, default: None Spacing in points between the label and the x-axis. Other Parameters ---------------- **kwargs : `.Text` properties `.Text` properties control the appearance of the label. See also -------- text : for information on how override and the optional args work """ if labelpad is not None: self.yaxis.labelpad = labelpad return self.yaxis.set_label_text(ylabel, fontdict, **kwargs) def set_color(self, color): """ Change the color of the secondary axes and all decorators Parameters ---------- color : Matplotlib color """ if self._orientation == 'x': self.tick_params(axis='x', colors=color) self.spines['bottom'].set_color(color) self.spines['top'].set_color(color) self.xaxis.label.set_color(color) else: self.tick_params(axis='y', colors=color) self.spines['left'].set_color(color) self.spines['right'].set_color(color) self.yaxis.label.set_color(color) _secax_docstring = ''' Warnings -------- This method is experimental as of 3.1, and the API may change. Parameters ---------- location : string or scalar The position to put the secondary axis. Strings can be 'top' or 'bottom', for x-oriented axises or 'left' or 'right' for y-oriented axises or a scalar can be a float indicating the relative position on the axes to put the new axes (0 being the bottom (left), and 1.0 being the top (right).) functions : 2-tuple of func, or Transform with an inverse If a 2-tuple of functions, the user specifies the transform function and its inverse. i.e. `functions=(lambda x: 2 / x, lambda x: 2 / x)` would be an reciprocal transform with a factor of 2. The user can also directly supply a subclass of `.transforms.Transform` so long as it has an inverse. See :doc:`/gallery/subplots_axes_and_figures/secondary_axis` for examples of making these conversions. Other Parameters ---------------- **kwargs : `~matplotlib.axes.Axes` properties. Other miscellaneous axes parameters. Returns ------- ax : axes._secondary_axes.SecondaryAxis ''' docstring.interpd.update(_secax_docstring=_secax_docstring)