Hi I am making a small program to select data from a plot. I would like to use the inbuilt matplotlib.widgets but I am misunderstanding the basics of connecting/disconnecting to the figure canvas.
Below is an example of the code I had in mind. If I declare the cursor/span widgets outside the event manager class the widgets are launched properly. However, this is not the case within the Event_Manager class.
But how should I modify the code to launch these widgets using a key event? Also how could I disconect/reconect them, also using key events?
import matplotlib.widgets as widgets
import numpy as np
import matplotlib.pyplot as plt
def Span_Manager(Wlow,Whig):
print Wlow,Whig
return
class Event_Manager:
def __init__(self, fig, ax):
self.fig = fig
self.ax = ax
self.redraw()
def redraw(self):
self.fig.canvas.draw()
def connect(self):
self.fig.canvas.mpl_connect('key_press_event', self.onKeyPress)
def onKeyPress(self, ev):
if ev.key == 'q':
print 'activate span selector'
Span = widgets.SpanSelector(ax, Span_Manager, 'horizontal', useblit=False, rectprops=dict(alpha=1, facecolor='Blue'))
elif ev.key == 'w':
print 'activate cursor'
cursor = widgets.Cursor(ax, useblit=True, color='red', linewidth=2)
self.redraw()
fig = plt.figure(figsize=(8, 6))
ax = fig.add_subplot(111)
x, y = 4*(np.random.rand(2, 100)-.5)
ax.plot(x, y, 'o')
ax.set_xlim(-2, 2)
ax.set_ylim(-2, 2)
mat_wid = Event_Manager(fig, ax)
mat_wid.connect()
# Span = widgets.SpanSelector(ax, Span_Manager, 'horizontal', useblit=False, rectprops=dict(alpha=1, facecolor='Blue'))
# cursor = widgets.Cursor(ax, useblit=True, color='red', linewidth=2)
plt.show()
Related
i am developing a GUI application for which there will be multiple dynamic subplots for which i would like to have a cursor integration for which is used "Matplotlib's MultiCursor widget" the code seems to be all good without any errors but the cursor alone is not being displayed on the screen
The below is a small snippet function which iam currently using
import numpy as np
import PySimpleGUI as sg
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg,
NavigationToolbar2Tk)
from matplotlib.widgets import Cursor
from matplotlib.widgets import MultiCursor
from matplotlib.gridspec import GridSpec
from matplotlib.figure import Figure
class Toolbar(NavigationToolbar2Tk):
def __init__(self, *args, **kwargs):
super(Toolbar, self).__init__(*args, **kwargs)
def repack(widget, option):
pack_info = widget.pack_info()
pack_info.update(option)
widget.pack(**pack_info)
def draw_figure_w_toolbar(canvas, fig, canvas_toolbar):
if canvas.children:
for child in canvas.winfo_children():
child.destroy()
if canvas_toolbar.children:
for child in canvas_toolbar.winfo_children():
child.destroy()
figure_canvas_agg = FigureCanvasTkAgg(fig, master=canvas)
figure_canvas_agg.draw_idle()
toolbar = Toolbar(figure_canvas_agg, canvas_toolbar)
toolbar.update()
figure_canvas_agg.get_tk_widget().pack(side='right', fill='both', expand=1)
layout=[
[
sg.Frame(
'Controls',
expand_x=True,
layout=[[
sg.Canvas(key='controls_cv')
]])
],
[
sg.Canvas(
key='fig_cv',
size=(1024, 525), #(W,H)
expand_x=True,
expand_y=True,
background_color='black')
],
]
window = sg.Window('Data Visualization Tool',
layout=layout,
location=(0, 0),
resizable=True,
margins=(0, 0),
finalize=True)
fig = Figure()
def get_data_ax(x_data, y_data, y_label, marker_sym=None):
ax = fig.add_subplot()
lines = ax.step(
x_data,
y_data,
marker=marker_sym,
where='post')
return ax, lines
cursor_handle_list = []
axes_handle_list = []
def on_move(event, flag=False, c_flag=False):
global cursor_present_flag, cursor_handle_list, axes_handle_list
if event.dblclick:
def change_cursor_position(handle_obj):
for handles in handle_obj:
handles.set_xdata(float(event.xdata))
if event.inaxes is not None:
ax = event.inaxes
if ax not in axes_handle_list:
cursor_handle = ax.axvline(event.xdata, color ='red', lw = .75, alpha = 0.65, visible=True)
cursor_handle_list.append(cursor_handle)
axes_handle_list.append(ax)
else:
change_cursor_position(cursor_handle_list)
draw_figure_w_toolbar(window['fig_cv'].TKCanvas, fig,
window['controls_cv'].TKCanvas)
window.refresh()
fig.canvas.mpl_connect("button_press_event", on_move)
t = np.arange(0.0, 2.0, 0.01)
s = 1 + np.sin(2 * np.pi * t)
num_rows = 2
gs = GridSpec(num_rows, 1, hspace=0)
ax0, lines = get_data_ax(t, s, 'test')
ax0.set_subplotspec(gs[0])
fig.add_subplot(ax0)
ax, lines = get_data_ax(t, s, 'test')
ax.set_subplotspec(gs[1])
fig.add_subplot(ax)
ax.get_shared_x_axes().join(ax0, ax)
graph = FigureCanvasTkAgg(fig, master=window['fig_cv'].TKCanvas)
cursor_multi = MultiCursor(graph, [ax,], color='r', lw=2.0, vertOn=True)
graph.draw()
draw_figure_w_toolbar(window['fig_cv'].TKCanvas, fig,
window['controls_cv'].TKCanvas)
while True:
event, values = window.read()
if event in (sg.WIN_CLOSED, 'Exit'):
break
I tried using axvline with matplotlib events but the results were not satisfactory
i saw somewhere that defining the return value of MultiCursor as gloabl should fix the issue but that did not happen in my case
next i tried simple putting plt.var_name as a variable for catching the returned object from MultiCursor but even this did not yeild me any result
Note: The code with mpl_connect and on_move callback with axvline integration were just an workaround i was trying as MultiCursor was not working you can discard that part if not required
It's because you created the MultiCursor widget before you created the FigureCanvasTkAgg for the axes objects. So do like this.
draw_figure_w_toolbar(window['fig_cv'].TKCanvas, ...)
cursor_multi = MultiCursor(None, [ax,], ...)
Also note that the first argument of the MultiCursor() is recommended to be set to None because it is ignored. Also your code contain many problems, such as an unused object graph.
I made a graph viewer GUI program in Python using Tkinter and matplotlib, where I switch between two graphs.
I have three problems I don't know how to fix:
Can't change the radiobutton after I move the slider it stops updating.
Can't change radiobutton after I switch the graph.
I would like to switch between graphs with 1 subplot and 2 subplots, but when I switch to graph with 2 subplots with slider and radiobar I can't move back to first.
I think the problem might be in the way I update the slider and radiobutton
Here is the code:
import matplotlib
import tkinter as Tk
matplotlib.use("TkAgg")
import matplotlib.pyplot as plt
import numpy as np
from tkinter import *
from matplotlib.backends.backend_tkagg import (
FigureCanvasTkAgg, NavigationToolbar2Tk)
from matplotlib.backend_bases import key_press_handler
from matplotlib.widgets import Slider, RadioButtons
# Seperated out config of plot to just do it once
def config_plot():
fig, ax = plt.subplots()
ax.set(xlabel='time (s)', ylabel='voltage (mV)',
title='Graph One')
return (fig, ax)
class matplotlibSwitchGraphs:
def __init__(self, master):
self.master = master
self.frame = Frame(self.master)
self.fig, self.ax = config_plot()
self.graphIndex = 0
self.canvas = FigureCanvasTkAgg(self.fig, self.master)
self.config_window()
self.draw_graph_one()
self.frame.pack(expand=YES, fill=BOTH)
def config_window(self):
self.canvas.mpl_connect("key_press_event", self.on_key_press)
toolbar = NavigationToolbar2Tk(self.canvas, self.master)
toolbar.update()
self.canvas.get_tk_widget().pack(side=TOP, fill=BOTH, expand=1)
self.button = Button(self.master, text="Quit", command=self._quit)
self.button.pack(side=BOTTOM)
self.button_switch = Button(self.master, text="Switch Graphs", command=self.switch_graphs)
self.button_switch.pack(side=BOTTOM)
def plot_data(self):
def func3(x, y):
return (1 - x / 2 + x ** 5 + y ** 3) * np.exp(-(x ** 2 + y ** 2))
dx, dy = 0.05, 0.05
x = np.arange(-3.0, 3.0, dx)
y = np.arange(-3.0, 3.0, dy)
X, Y = np.meshgrid(x, y)
self.extent = np.min(x), np.max(x), np.min(y), np.max(y)
self.Z1 = np.add.outer(range(8), range(8)) % 2 # chessboard
self.Z2 = func3(X, Y)
def draw_graph_one(self):
self.plot_data()
self.ax.remove()
self.ax = plt.imshow(self.Z2, cmap=plt.cm.viridis, alpha=.9, interpolation='bilinear',
extent=self.extent)
self.canvas.draw()
def draw_graph_two(self):
self.plot_data()
self.ax.remove()
self.ax = plt.subplot(1, 2, 1)
self.ax = plt.imshow(self.Z1, cmap=plt.cm.gray, interpolation='nearest',
extent=self.extent)
self.ax = plt.subplot(1, 2, 2)
self.a = plt.imshow(self.Z2, cmap=plt.cm.viridis, alpha=.9, interpolation='bilinear',
extent=self.extent)
self.b = plt.imshow(self.Z1, cmap=plt.cm.gray, interpolation='nearest',
extent=self.extent)
self.canvas.draw()
plt.subplots_adjust(left=0.15, bottom=0.15)
slider_ax = plt.axes([0.06, 0.25, 0.0225, 0.5])
alfa_slider = Slider(slider_ax,
label="Transparency",
valmin=0,
valmax=1,
valinit=0,
orientation="vertical"
)
alfa_slider.on_changed(self.update_slider)
rax = plt.axes([0.06, 0.05, 0.15, 0.15])
radio = RadioButtons(rax, ('Reds', 'Greens', 'Blues', 'Oranges', 'Wistia', 'plasma', 'inferno'), active=0)
radio.on_clicked(self.update_radio)
self.canvas.draw()
def update_slider(self,alpha_):
self.b.set_alpha(alpha_)
self.canvas.draw()
def update_radio(self,label_):
self.b.set_cmap(label_)
self.canvas.draw()
def on_key_press(self,event,toolbar):
print("you pressed {}".format(event.key))
key_press_handler(event, self.canvas, toolbar)
def _quit(self):
self.master.quit() # stops mainloop
def switch_graphs(self):
# Need to call the correct draw, whether we're on graph one or two
self.graphIndex = (self.graphIndex + 1) % 2
if self.graphIndex == 0:
self.draw_graph_one()
else:
self.draw_graph_two()
def main():
root = Tk()
matplotlibSwitchGraphs(root)
root.mainloop()
if __name__ == '__main__':
main()
I tried to input update_slider and update_radio function inside of function, but than I cant use self.canvas.draw().
Also .remove() and .cla() doesn't clear the window.
Here is the view of the graphs I would like to switch between:
Answering your last question first, your big issue is that you are trying to use one figure to display two seperate graphs, without understanding how pyplot actually works. It is possible to do so, as I will outline below, but you lose any modifications you make to the graphs when you switch between them. I would recommend reading the working with multiple axes and figures section of the pyplot tutorial. The key takeaway as that in MATLAB and pyplot, all plotting functions are applied to the last figure and axes.
When you call self.draw_graph_two(), the last axes you create are the RadioButtons. Therefore, pyplot has these axes as the current axes. When you then call self.draw_graph_one() for the second time (the first time was when you intialised), it draws the plot on the current figure and current axes, where the RadioButtons are.
To solve this, call plt.clf() as the first line of draw_graph_one and draw_graph_two, before attempting to draw the new graph. This clears the figure, allowing for a new plot to be drawn from scratch (which is what your two draw functions do). This allows you to continuously switch between your two plots, although each time you switch the plot is cleared and any modifications to the plot are lost. You can also remove the self.ax.remove() lines, as they cause errors and are not needed.
For your first two questions, these can be answered by reading the documentation for the RadioButtons and Slider here. You must keep a reference to the widgets for them to remain responsive. So modifying your draw_graph_two to return alfa_slider and radio keeps these widgets responsive. Alternatively, declaring them as instance variables also keeps a reference (self.alfa_slider and self.radio).
So your working graph viewer is:
import matplotlib
import tkinter as tk
matplotlib.use("TkAgg")
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.backends.backend_tkagg import (
FigureCanvasTkAgg, NavigationToolbar2Tk)
from matplotlib.backend_bases import key_press_handler
from matplotlib.widgets import Slider, RadioButtons
# Seperated out config of plot to just do it once
def config_plot():
fig, ax = plt.subplots()
ax.set(xlabel='time (s)', ylabel='voltage (mV)',
title='Graph One')
return (fig, ax)
class matplotlibSwitchGraphs:
def __init__(self, master):
self.master = master
self.frame = tk.Frame(self.master)
self.fig, self.ax = config_plot()
self.graphIndex = 0
self.canvas = FigureCanvasTkAgg(self.fig, self.master)
self.config_window()
self.plot_data()
self.draw_graph_one()
self.frame.pack(expand=True, fill=tk.BOTH)
def config_window(self):
self.canvas.mpl_connect("key_press_event", self.on_key_press)
toolbar = NavigationToolbar2Tk(self.canvas, self.master)
toolbar.update()
self.canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)
self.button = tk.Button(self.master, text="Quit", command=self._quit)
self.button.pack(side=tk.BOTTOM)
self.button_switch = tk.Button(self.master, text="Switch Graphs", command=self.switch_graphs)
self.button_switch.pack(side=tk.BOTTOM)
def plot_data(self):
def func3(x, y):
return (1 - x / 2 + x ** 5 + y ** 3) * np.exp(-(x ** 2 + y ** 2))
dx, dy = 0.05, 0.05
x = np.arange(-3.0, 3.0, dx)
y = np.arange(-3.0, 3.0, dy)
X, Y = np.meshgrid(x, y)
self.extent = np.min(x), np.max(x), np.min(y), np.max(y)
self.Z1 = np.add.outer(range(8), range(8)) % 2 # chessboard
self.Z2 = func3(X, Y)
def draw_graph_one(self):
plt.clf()
self.ax = plt.imshow(self.Z2, cmap=plt.cm.viridis, alpha=.9, interpolation='bilinear',
extent=self.extent)
self.canvas.draw()
def draw_graph_two(self):
plt.clf()
self.ax = plt.subplot(1, 2, 1)
self.ax = plt.imshow(self.Z1, cmap=plt.cm.gray, interpolation='nearest',
extent=self.extent)
self.ax = plt.subplot(1, 2, 2)
self.a = plt.imshow(self.Z2, cmap=plt.cm.viridis, alpha=.9, interpolation='bilinear',
extent=self.extent)
self.b = plt.imshow(self.Z1, cmap=plt.cm.gray, interpolation='nearest',
extent=self.extent)
self.canvas.draw()
plt.subplots_adjust(left=0.15, bottom=0.15)
slider_ax = plt.axes([0.06, 0.25, 0.0225, 0.5])
self.alfa_slider = Slider(slider_ax,
label="Transparency",
valmin=0,
valmax=1,
valinit=0,
orientation="vertical"
)
self.alfa_slider.on_changed(self.update_slider)
rax = plt.axes([0.06, 0.05, 0.15, 0.15])
self.radio = RadioButtons(rax, ('Reds', 'Greens', 'Blues', 'Oranges', 'Wistia', 'plasma', 'inferno'), active=0)
self.radio.on_clicked(self.update_radio)
self.canvas.draw()
def update_slider(self,alpha_):
self.b.set_alpha(1-alpha_)
self.canvas.draw()
def update_radio(self,label_):
self.b.set_cmap(label_)
self.canvas.draw()
def on_key_press(self,event,toolbar):
print("you pressed {}".format(event.key))
key_press_handler(event, self.canvas, toolbar)
def _quit(self):
self.master.quit() # stops mainloop
def switch_graphs(self):
# Need to call the correct draw, whether we're on graph one or two
self.graphIndex = (self.graphIndex + 1) % 2
if self.graphIndex == 0:
self.draw_graph_one()
else:
self.draw_graph_two()
def main():
root = tk.Tk()
matplotlibSwitchGraphs(root)
root.mainloop()
if __name__ == '__main__':
main()
Note I also made some other slight modifications. Don't use from tkinter import *, you had already imported it above and using import * is a bad habit. I reversed the slider so that the transparency makes sense. self.plot_data() is only called once in __init__ as it doesn't change.
I have the following class that draws a vertical line through the y-axis, so that when I click on it a horizontal line gets drawn at the location.
My goal is to get the y-coordinate to actually print right at the y-axis where the horizontal line gets drawn. For testing, I am trying to print a title with the y-ccordinate, but it is not working as expected.
What I am trying to really accomplish is to make the y-axis on a bar plot clickable so that the user can select a point on the y-axis, and then a bunch of "stuff" happens (including the drawing of a horizontal line). I really see no other way to make this happen, other than drawing a plottable vertical line through the y-axis to make it pickable. This seems rather kludgey, but I have not had any success with any other methods.
import matplotlib.pyplot as plt
class PointPicker(object):
def __init__(self):
self.fig = plt.figure()
self.ax = self.fig.add_subplot(111)
self.lines2d, = self.ax.plot((0, 0), (-6000, 10000), 'k-', linestyle='-',picker=5)
self.fig.canvas.mpl_connect('pick_event', self.onpick)
self.fig.canvas.mpl_connect('key_press_event', self.onpress)
fig.canvas.mpl_connect('button_press_event', self.onclick)
def onpress(self, event):
"""define some key press events"""
if event.key.lower() == 'q':
sys.exit()
def onpick(self,event):
x = event.mouseevent.xdata
y = event.mouseevent.ydata
L = self.ax.axhline(y=y)
print(y)
ax.axvspan(0, 0, facecolor='y', alpha=0.5, picker=10)
self.fig.canvas.draw()
def onclick(event):
self.fig.canvas.set_title('Selected item came from {}'.format(event.ydata))
print(event.xdata, event.ydata)
if __name__ == '__main__':
plt.ion()
p = PointPicker()
plt.show()
Assuming there is no ther way to achieve my end result, all is well with this method, except I cannot for the life of me get the title to print (using the self.fig.canvas.set_title('Selected item came from {}'.format(event.ydata)).
You can use the 'button_press_event' to connect to a method, which verifies that the click has happened close enough to the yaxis spine and then draws a horizontal line using the clicked coordinate.
import matplotlib.pyplot as plt
class PointPicker(object):
def __init__(self, ax, clicklim=0.05):
self.fig=ax.figure
self.ax = ax
self.clicklim = clicklim
self.horizontal_line = ax.axhline(y=.5, color='y', alpha=0.5)
self.text = ax.text(0,0.5, "")
print self.horizontal_line
self.fig.canvas.mpl_connect('button_press_event', self.onclick)
def onclick(self, event):
if event.inaxes == self.ax:
x = event.xdata
y = event.ydata
xlim0, xlim1 = ax.get_xlim()
if x <= xlim0+(xlim1-xlim0)*self.clicklim:
self.horizontal_line.set_ydata(y)
self.text.set_text(str(y))
self.text.set_position((xlim0, y))
self.fig.canvas.draw()
if __name__ == '__main__':
fig = plt.figure()
ax = fig.add_subplot(111)
ax.bar([0,2,3,5],[4,5,1,3], color="#dddddd")
p = PointPicker(ax)
plt.show()
I would like the cursor to be visible across all axes vertically but only visible horizontally for the axis that the mouse pointer is on.
This is a code exert of what I am using at the moment.
import matplotlib.pyplot as plt
from matplotlib.widgets import MultiCursor
fig = plt.figure(facecolor='#07000d')
ax1 = plt.subplot2grid((2,4), (0,0), rowspan=1,colspan=4, axisbg='#aaaaaa')
ax2 = plt.subplot2grid((2,4), (1,0), rowspan=1,colspan=4, axisbg='#aaaaaa')
multi = MultiCursor(fig.canvas, (ax1, ax2), color='r', lw=.5, horizOn=True, vertOn=True)
plt.show()
This is what I have. What I would like is to have the horizontal cursor to be only visible for the axis that mouse pointer is on but have the vertical visible for both.
So I came up with a solution. I made my own custom cursor using mouse events wrapped in a class. Works great. You can add your axes in an array/list.
import numpy as np
import matplotlib.pyplot as plt
class CustomCursor(object):
def __init__(self, axes, col, xlimits, ylimits, **kwargs):
self.items = np.zeros(shape=(len(axes),3), dtype=np.object)
self.col = col
self.focus = 0
i = 0
for ax in axes:
axis = ax
axis.set_gid(i)
lx = ax.axvline(ymin=ylimits[0],ymax=ylimits[1],color=col)
ly = ax.axhline(xmin=xlimits[0],xmax=xlimits[1],color=col)
item = list([axis,lx,ly])
self.items[i] = item
i += 1
def show_xy(self, event):
if event.inaxes:
self.focus = event.inaxes.get_gid()
for ax in self.items[:,0]:
self.gid = ax.get_gid()
for lx in self.items[:,1]:
lx.set_xdata(event.xdata)
if event.inaxes.get_gid() == self.gid:
self.items[self.gid,2].set_ydata(event.ydata)
self.items[self.gid,2].set_visible(True)
plt.draw()
def hide_y(self, event):
for ax in self.items[:,0]:
if self.focus == ax.get_gid():
self.items[self.focus,2].set_visible(False)
if __name__ == '__main__':
fig = plt.figure(facecolor='#07000d')
ax1 = plt.subplot2grid((2,4), (0,0), rowspan=1,colspan=4, axisbg='#aaaaaa')
ax2 = plt.subplot2grid((2,4), (1,0), rowspan=1,colspan=4, axisbg='#aaaaaa')
cc = CustomCursor([ax1,ax2], col='red', xlimits=[0,100], ylimits=[0,100], markersize=30,)
fig.canvas.mpl_connect('motion_notify_event', cc.show_xy)
fig.canvas.mpl_connect('axes_leave_event', cc.hide_y)
plt.tight_layout()
plt.show()
I am writing a class to process images. In that class, I want to define a method that can allow me to return coordinates of the mouse clicks. I can get the coordinates as an attribute but if I call the method to return the coordinates, I get an empty tuple
Here is the code:
import cv2
import matplotlib.pyplot as plt
class TestClass():
def __init__(self):
self.fname = 'image.jpg'
self.img = cv2.imread(self.fname)
self.point = ()
def getCoord(self):
fig = plt.figure()
ax = fig.add_subplot(111)
plt.imshow(self.img)
cid = fig.canvas.mpl_connect('button_press_event', self.__onclick__)
return self.point
def __onclick__(self,click):
self.point = (click.xdata,click.ydata)
return self.point
Your code works for me, as long as I insert plt.show() after mpl_connect in getCoord:
def getCoord(self):
fig = plt.figure()
ax = fig.add_subplot(111)
plt.imshow(self.img)
cid = fig.canvas.mpl_connect('button_press_event', self.__onclick__)
plt.show()
return self.point