import functools import numbers import numpy as np from matplotlib import _api, _docstring, transforms import matplotlib.ticker as mticker from matplotlib.axes._base import _AxesBase, _TransformedBoundsLocator from matplotlib.axis import Axis from matplotlib.transforms import Transform class SecondaryAxis(_AxesBase): """ General class to hold a Secondary_X/Yaxis. """ def __init__(self, parent, orientation, location, functions, transform=None, **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. """ _api.check_in_list(["x", "y"], orientation=orientation) self._functions = functions self._parent = parent self._orientation = orientation self._ticks_set = False fig = self._parent.get_figure(root=False) if self._orientation == 'x': super().__init__(fig, [0, 1., 1, 0.0001], **kwargs) self._axis = self.xaxis self._locstrings = ['top', 'bottom'] self._otherstrings = ['left', 'right'] else: # 'y' super().__init__(fig, [0, 1., 0.0001, 1], **kwargs) self._axis = self.yaxis self._locstrings = ['right', 'left'] self._otherstrings = ['top', 'bottom'] self._parentscale = None # this gets positioned w/o constrained_layout so exclude: self.set_location(location, transform) self.set_functions(functions) # styling: otheraxis = self.yaxis if self._orientation == 'x' else self.xaxis otheraxis.set_major_locator(mticker.NullLocator()) otheraxis.set_ticks_position('none') self.spines[self._otherstrings].set_visible(False) self.spines[self._locstrings].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 : {'top', 'bottom', 'left', 'right'} Either 'top' or 'bottom' for orientation='x' or 'left' or 'right' for orientation='y' axis. """ _api.check_in_list(self._locstrings, align=align) if align == self._locstrings[1]: # Need to change the orientation. self._locstrings = 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, transform=None): """ Set the vertical or horizontal location of the axes in parent-normalized coordinates. Parameters ---------- location : {'top', 'bottom', 'left', 'right'} or float The position to put the secondary axis. Strings can be 'top' or 'bottom' for orientation='x' and 'right' or 'left' for orientation='y'. A float indicates 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). transform : `.Transform`, optional Transform for the location to use. Defaults to the parent's ``transAxes``, so locations are normally relative to the parent axes. .. versionadded:: 3.9 """ _api.check_isinstance((transforms.Transform, None), transform=transform) # This puts the rectangle into figure-relative coordinates. if isinstance(location, str): _api.check_in_list(self._locstrings, location=location) self._pos = 1. if location in ('top', 'right') else 0. elif isinstance(location, numbers.Real): self._pos = location else: raise ValueError( f"location must be {self._locstrings[0]!r}, " f"{self._locstrings[1]!r}, or a float, not {location!r}") self._loc = location if self._orientation == 'x': # An x-secondary axes is like an inset axes from x = 0 to x = 1 and # from y = pos to y = pos + eps, in the parent's transAxes coords. bounds = [0, self._pos, 1., 1e-10] # If a transformation is provided, use its y component rather than # the parent's transAxes. This can be used to place axes in the data # coords, for instance. if transform is not None: transform = transforms.blended_transform_factory( self._parent.transAxes, transform) else: # 'y' bounds = [self._pos, 0, 1e-10, 1] if transform is not None: transform = transforms.blended_transform_factory( transform, self._parent.transAxes) # Use provided x axis # If no transform is provided, use the parent's transAxes if transform is None: transform = self._parent.transAxes # this locator lets the axes move in the parent axes coordinates. # so it never needs to know where the parent is explicitly in # figure coordinates. # it gets called in ax.apply_aspect() (of all places) self.set_axes_locator(_TransformedBoundsLocator(bounds, transform)) def apply_aspect(self, position=None): # docstring inherited. self._set_lims() super().apply_aspect(position) @functools.wraps(_AxesBase.set_xticks) def set_xticks(self, *args, **kwargs): if self._orientation == "y": raise TypeError("Cannot set xticks on a secondary y-axis") ret = super().set_xticks(*args, **kwargs) self._ticks_set = True return ret @functools.wraps(_AxesBase.set_yticks) def set_yticks(self, *args, **kwargs): if self._orientation == "x": raise TypeError("Cannot set yticks on a secondary x-axis") ret = super().set_yticks(*args, **kwargs) self._ticks_set = True return ret @functools.wraps(Axis.set_ticks) def set_ticks(self, *args, **kwargs): ret = self._axis.set_ticks(*args, **kwargs) 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 (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 isinstance(functions, Transform): self._functions = ( functions.transform, lambda x: functions.inverted().transform(x) ) 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') self._set_scale() def draw(self, renderer): """ 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) 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 else: # 'y' pscale = self._parent.yaxis.get_scale() set_scale = self.set_yscale if pscale == self._parentscale: return if self._ticks_set: ticks = self._axis.get_ticklocs() # need to invert the roles here for the ticks to line up. set_scale('functionlog' if pscale == 'log' else 'function', 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(mticker.FixedLocator(ticks)) # If the parent scale doesn't change, we can skip this next time. self._parentscale = pscale 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 else: # 'y' lims = self._parent.get_ylim() set_lim = self.set_ylim 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 set_aspect(self, *args, **kwargs): """ Secondary Axes cannot set the aspect ratio, so calling this just sets a warning. """ _api.warn_external("Secondary Axes can't set the aspect ratio") def set_color(self, color): """ Change the color of the secondary Axes and all decorators. Parameters ---------- color : :mpltype:`color` """ axis = self._axis_map[self._orientation] axis.set_tick_params(colors=color) for spine in self.spines.values(): if spine.axis is axis: spine.set_color(color) axis.label.set_color(color) _secax_docstring = ''' Warnings -------- This method is experimental as of 3.1, and the API may change. Parameters ---------- location : {'top', 'bottom', 'left', 'right'} or float The position to put the secondary axis. Strings can be 'top' or 'bottom' for orientation='x' and 'right' or 'left' for orientation='y'. A float indicates 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). 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. Both functions must accept numpy arrays as input. 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. transform : `.Transform`, optional If specified, *location* will be placed relative to this transform (in the direction of the axis) rather than the parent's axis. i.e. a secondary x-axis will use the provided y transform and the x transform of the parent. .. versionadded:: 3.9 Returns ------- ax : axes._secondary_axes.SecondaryAxis The returned Axes is overlaid on top of the original Axes and all components except for the complementary axis are hidden. You may modify the complementary axis, e.g. by setting ticks or an axis label. However, it is not designed to hold data, so that you should not call any plotting methods on it. Its limits are derived from the parent Axes via the specified transformation, and setting limits on the secondary axis (e.g., via ``set_xlim`` or ``set_ylim``) has no effect. Other Parameters ---------------- **kwargs : `~matplotlib.axes.Axes` properties. Other miscellaneous Axes parameters. ''' _docstring.interpd.register(_secax_docstring=_secax_docstring)