>>> """
================
Axes Zoom Effect
================

"""
... 
... import matplotlib.pyplot as plt
... 
... from matplotlib.transforms import (
...     Bbox, TransformedBbox, blended_transform_factory)
... from mpl_toolkits.axes_grid1.inset_locator import (
...     BboxPatch, BboxConnector, BboxConnectorPatch)
... 
... 
... def connect_bbox(bbox1, bbox2,
...                  loc1a, loc2a, loc1b, loc2b,
...                  prop_lines, prop_patches=None):
...     if prop_patches is None:
...         prop_patches = {
...             **prop_lines,
...             "alpha": prop_lines.get("alpha", 1) * 0.2,
...             "clip_on": False,
...         }
... 
...     c1 = BboxConnector(
...         bbox1, bbox2, loc1=loc1a, loc2=loc2a, clip_on=False, **prop_lines)
...     c2 = BboxConnector(
...         bbox1, bbox2, loc1=loc1b, loc2=loc2b, clip_on=False, **prop_lines)
... 
...     bbox_patch1 = BboxPatch(bbox1, **prop_patches)
...     bbox_patch2 = BboxPatch(bbox2, **prop_patches)
... 
...     p = BboxConnectorPatch(bbox1, bbox2,
...                            # loc1a=3, loc2a=2, loc1b=4, loc2b=1,
...                            loc1a=loc1a, loc2a=loc2a, loc1b=loc1b, loc2b=loc2b,
...                            clip_on=False,
...                            **prop_patches)
... 
...     return c1, c2, bbox_patch1, bbox_patch2, p
... 
... 
... def zoom_effect01(ax1, ax2, xmin, xmax, **kwargs):
...     """
    Connect *ax1* and *ax2*. The *xmin*-to-*xmax* range in both axes will
    be marked.

    Parameters
    ----------
    ax1
        The main axes.
    ax2
        The zoomed axes.
    xmin, xmax
        The limits of the colored area in both plot axes.
    **kwargs
        Arguments passed to the patch constructor.
    """
... 
...     bbox = Bbox.from_extents(xmin, 0, xmax, 1)
... 
...     mybbox1 = TransformedBbox(bbox, ax1.get_xaxis_transform())
...     mybbox2 = TransformedBbox(bbox, ax2.get_xaxis_transform())
... 
...     prop_patches = {**kwargs, "ec": "none", "alpha": 0.2}
... 
...     c1, c2, bbox_patch1, bbox_patch2, p = connect_bbox(
...         mybbox1, mybbox2,
...         loc1a=3, loc2a=2, loc1b=4, loc2b=1,
...         prop_lines=kwargs, prop_patches=prop_patches)
... 
...     ax1.add_patch(bbox_patch1)
...     ax2.add_patch(bbox_patch2)
...     ax2.add_patch(c1)
...     ax2.add_patch(c2)
...     ax2.add_patch(p)
... 
...     return c1, c2, bbox_patch1, bbox_patch2, p
... 
... 
... def zoom_effect02(ax1, ax2, **kwargs):
...     """
    ax1 : the main axes
    ax1 : the zoomed axes

    Similar to zoom_effect01.  The xmin & xmax will be taken from the
    ax1.viewLim.
    """
... 
...     tt = ax1.transScale + (ax1.transLimits + ax2.transAxes)
...     trans = blended_transform_factory(ax2.transData, tt)
... 
...     mybbox1 = ax1.bbox
...     mybbox2 = TransformedBbox(ax1.viewLim, trans)
... 
...     prop_patches = {**kwargs, "ec": "none", "alpha": 0.2}
... 
...     c1, c2, bbox_patch1, bbox_patch2, p = connect_bbox(
...         mybbox1, mybbox2,
...         loc1a=3, loc2a=2, loc1b=4, loc2b=1,
...         prop_lines=kwargs, prop_patches=prop_patches)
... 
...     ax1.add_patch(bbox_patch1)
...     ax2.add_patch(bbox_patch2)
...     ax2.add_patch(c1)
...     ax2.add_patch(c2)
...     ax2.add_patch(p)
... 
...     return c1, c2, bbox_patch1, bbox_patch2, p
... 
... 
... axs = plt.figure().subplot_mosaic([
...     ["zoom1", "zoom2"],
...     ["main", "main"],
... ])
... 
... axs["main"].set(xlim=(0, 5))
... zoom_effect01(axs["zoom1"], axs["main"], 0.2, 0.8)
... axs["zoom2"].set(xlim=(2, 3))
... zoom_effect02(axs["zoom2"], axs["main"])
... 
... plt.show()
...