Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. Pyplot is a state-based interface to a Matplotlib module which provides a MATLAB-like interface.
matplotlib.pyplot.connect() Function
This method is used to connect an event with string s to a function.
Syntax: matplotlib.pyplot.connect(s, func)
Parameters: This method accept the following parameters that are described below:
s(str): One of the following events ids:
1. ‘button_press_event’
2. ‘button_release_event’
3. ‘draw_event’
4. ‘key_press_event’
5. ‘key_release_event’
6. ‘motion_notify_event’
7. ‘pick_event’
8. ‘resize_event’
9. ‘scroll_event’
10. ‘figure_enter_event’,
11. ‘figure_leave_event’,
12. ‘axes_enter_event’,
13. ‘axes_leave_event’
14. ‘close_event’.
func(callable): The callback function to be executed, which must have the signature:
def func(event: Event) -> AnyReturns(cid): A connection id that can be used with FigureCanvasBase.mpl_disconnect.
Example 1 :
# matplotlib.pyplot.connect() from matplotlib.backend_bases import MouseButton import matplotlib.pyplot as plt import numpy as np t = np.arange(0.0, 1.0, 0.01) s = np.sin(2 * np.pi * t) fig, ax = plt.subplots() ax.plot(t, s) def on_move(event): # get the x and y pixel coords x, y = event.x, event.y if event.inaxes: ax = event.inaxes # the axes instance print('data coords % f % f' % (event.xdata, event.ydata)) def on_click(event): if event.button is MouseButton.LEFT: print('disconnecting callback') plt.disconnect(binding_id) binding_id = plt.connect('motion_notify_event', on_move) plt.connect('button_press_event', on_click) plt.show() |
Output :
Example 2 :
from matplotlib.widgets import RectangleSelector import numpy as np import matplotlib.pyplot as plt def line_select_callback(eclick, erelease): # Callback for line selection. # *eclick * and * erelease * # are the press and release events. x1, y1 = eclick.xdata, eclick.ydata x2, y2 = erelease.xdata, erelease.ydata print("(% 3.2f, % 3.2f) --> (% 3.2f, % 3.2f)" % (x1, y1, x2, y2)) print(" The button you used were: % s % s" % (eclick.button, erelease.button)) def toggle_selector(event): print(' Key pressed.') if event.key in ['Q', 'q'] and toggle_selector.RS.active: print(' RectangleSelector deactivated.') toggle_selector.RS.set_active(False) print(' RectangleSelector activated.') toggle_selector.RS.set_active(True) # make a new plotting range fig, current_ax = plt.subplots() # If N is large one can see N = 100000 # improvement by use blitting ! # plt.plot(x, +np.sin(.2 * np.pi * x), # lw = 3.5, c ='b', alpha =.7) # plot something x = np.linspace(0.0, 10.0, N) plt.plot(x, +np.cos(.2 * np.pi * x), lw = 3.5, c ='c', alpha =.5) plt.plot(x, -np.sin(.2 * np.pi * x), lw = 3.5, c ='r', alpha =.3) print("\n click --> release") # drawtype is 'box' or 'line' or 'none' toggle_selector.RS = RectangleSelector(current_ax, line_select_callback, drawtype ='box', useblit = True, button =[1, 3], # don't use middle button minspanx = 5, minspany = 5, spancoords ='pixels', interactive = True) plt.connect('key_press_event', toggle_selector) plt.show() |
Output :
