class Magnifier(object):
"""A magnification of a matplotlib axes
It zooms into the region where the mouse pointer is, when it enters the
source axes. The appearance of the plot is defined by the :meth:`make_plot`
method."""
@property
def dx(self):
val = self.slider.val
ret = np.abs(np.diff(self.ax_src.get_xlim())) * (100 - val) / 200.
return -ret if self.ax.xaxis_inverted() else ret
@property
def dy(self):
val = self.slider.val
ret = np.abs(np.diff(self.ax_src.get_ylim())) * (100 - val) / 200.
return -ret if self.ax.yaxis_inverted() else ret
cid_enter = None
cid_motion = None
cid_leave = None
ax = None
def __init__(self, ax_src, ax=None, *args, **kwargs):
self.ax_src = ax_src
if ax is None:
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
fig.canvas.set_window_title('Figure %i: Zoom of figure %i' %
(fig.number, ax_src.figure.number))
self.ax = ax
self.point = ax.plot([np.mean(ax.get_xlim())],
[np.mean(ax.get_ylim())],
'ro',
visible=False,
zorder=10)[0]
self.make_plot(*args, **kwargs)
self.enable_zoom()
if isinstance(ax, SubplotBase):
slider_ax, kw = mcbar.make_axes_gridspec(ax,
orientation='horizontal',
location='bottom')
else:
slider_ax, kw = mcbar.make_axes(ax,
position='bottom',
orientation='horizontal')
slider_ax.set_aspect('auto')
slider_ax._hold = True
self.slider = Slider(slider_ax, 'Zoom', 0, 99.5, valfmt='%1.2g %%')
self.slider.set_val(90)
self.slider.on_changed(self.adjust_limits)
self.adjust_limits(90)
def adjust_limits(self, zoom_val):
x = np.mean(self.ax.get_xlim())
y = np.mean(self.ax.get_ylim())
dx = self.dx
dy = self.dy
self.ax.set_xlim(x - dx, x + dx)
self.ax.set_ylim(y - dy, y + dy)
self.ax.figure.canvas.draw()
def make_plot(self, image, *args, **kwargs):
self.plot_image = self.ax.imshow(image, *args, **kwargs)
def onmotion(self, event):
if event.inaxes != self.ax_src or self.ax is None:
return
x, y = event.xdata, event.ydata
dx = self.dx
dy = self.dy
ax = self.ax
xmin, xmax = x - dx, x + dx
ymin, ymax = y - dy, y + dy
ax.set_xlim(xmin, xmax)
ax.set_ylim(ymin, ymax)
self.point.set_xdata([x])
self.point.set_ydata([y])
self.point.set_visible(True)
ax.figure.canvas.draw()
def onenter(self, event):
if event.inaxes != self.ax_src or self.ax is None:
return
canvas = self.ax_src.figure.canvas
canvas.mpl_disconnect(self.cid_enter)
self.cid_leave = canvas.mpl_connect('axes_leave_event', self.onleave)
self.cid_motion = canvas.mpl_connect('motion_notify_event',
self.onmotion)
def close(self):
"""Close the magnifier and the associated plots"""
import matplotlib.pyplot as plt
try:
self.plot_image.remove()
except (AttributeError, ValueError):
pass
try:
self.point.remove()
except (AttributeError, ValueError):
pass
self.disconnect()
fig = self.ax.figure
fig.delaxes(self.ax)
self.slider.disconnect_events()
fig.delaxes(self.slider.ax)
plt.close(self.ax.figure)
del self.plot_image, self.ax, self.ax_src, self.slider
def onleave(self, event):
canvas = self.ax_src.figure.canvas
canvas.mpl_disconnect(self.cid_leave)
canvas.mpl_disconnect(self.cid_motion)
self.enable_zoom()
self.point.set_visible(False)
if self.ax is not None:
self.ax.figure.canvas.draw()
def enable_zoom(self):
self.cid_enter = self.ax_src.figure.canvas.mpl_connect(
'axes_enter_event', self.onenter)
def disconnect(self):
canvas = self.ax_src.figure.canvas
for cid in [self.cid_enter, self.cid_leave, self.cid_motion]:
if cid is not None:
canvas.mpl_disconnect(cid)
