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 :