-
-
Save ianhi/b638e09fa7a00764ea539940a0519af9 to your computer and use it in GitHub Desktop.
factory for adding zoom callback to matplotlib imshow - now available via https://github.com/ianhi/mpl-interactions
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import matplotlib.pyplot as plt | |
| def zoom_factory(ax,base_scale = 1.1): | |
| """ | |
| parameters | |
| ---------- | |
| ax : matplotlib axes object | |
| axis on which to implement scroll to zoom | |
| base_scale : float | |
| how much zoom on each tick of scroll wheel | |
| returns | |
| ------- | |
| disconnect_zoom : function | |
| call this to disconnect the scroll listener | |
| """ | |
| def limits_to_range(lim): | |
| return lim[1] - lim[0] | |
| fig = ax.get_figure() # get the figure of interest | |
| toolbar = fig.canvas.toolbar | |
| toolbar.push_current() | |
| orig_xlim = ax.get_xlim() | |
| orig_ylim = ax.get_ylim() | |
| orig_yrange = limits_to_range(orig_ylim) | |
| orig_xrange = limits_to_range(orig_xlim) | |
| orig_center = ((orig_xlim[0]+orig_xlim[1])/2, (orig_ylim[0]+orig_ylim[1])/2) | |
| def zoom_fun(event): | |
| # get the current x and y limits | |
| cur_xlim = ax.get_xlim() | |
| cur_ylim = ax.get_ylim() | |
| # set the range | |
| cur_xrange = (cur_xlim[1] - cur_xlim[0])*.5 | |
| cur_yrange = (cur_ylim[1] - cur_ylim[0])*.5 | |
| xdata = event.xdata # get event x location | |
| ydata = event.ydata # get event y location | |
| if event.button == 'up': | |
| # deal with zoom in | |
| scale_factor = base_scale | |
| elif event.button == 'down': | |
| # deal with zoom out | |
| scale_factor = 1/base_scale | |
| else: | |
| # deal with something that should never happen | |
| scale_factor = 1 | |
| # set new limits | |
| new_xlim = [xdata - (xdata-cur_xlim[0]) / scale_factor, | |
| xdata + (cur_xlim[1]-xdata) / scale_factor] | |
| new_ylim = [ydata - (ydata-cur_ylim[0]) / scale_factor, | |
| ydata + (cur_ylim[1]-ydata) / scale_factor] | |
| new_yrange = limits_to_range(new_ylim) | |
| new_xrange = limits_to_range(new_xlim) | |
| if np.abs(new_yrange)>np.abs(orig_yrange): | |
| new_ylim = orig_center[1] -new_yrange/2 , orig_center[1] +new_yrange/2 | |
| if np.abs(new_xrange)>np.abs(orig_xrange): | |
| new_xlim = orig_center[0] -new_xrange/2 , orig_center[0] +new_xrange/2 | |
| ax.set_xlim(new_xlim) | |
| ax.set_ylim(new_ylim) | |
| toolbar.push_current() | |
| ax.figure.canvas.draw_idle() # force re-draw | |
| # attach the call back | |
| cid = fig.canvas.mpl_connect('scroll_event',zoom_fun) | |
| def disconnect_zoom(): | |
| fig.canvas.mpl_disconnect(cid) | |
| #return the disconnect function | |
| return disconnect_zoom |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
This fork adds on two things: