I have an application where the user can open / close many windows containing different plots. At first I attempted to use a new Matplotlib Figure for each window but I had trouble releasing the memory when closing a window with a plot.
An option I am looking at is using a separate FigureCanvasQTAgg for each window and having them share one single Figure. The problem then becomes that if I clear and replot the figure for one window it affects all others.
My question is the following - is there a way to "freeze" a FigureCanvasQTAgg once it has been drawn so that it is not updated when the Figure is cleared / replotted?
One idea I had was to use an EventFilter to catch and stop the paint event for the FigureCanvasQTAgg once it has been drawn so that it is no longer repainted. However I have not been able to make it work. I have not used EventFilter before so I may be doing it incorrectly.
Here is the code, using a simple example with 2 windows using one single Figure. When the second window is plotted the first window gets cleared, which is what I want to avoid. If anyone can spot what's wrong or suggest another way to prevent the first window to be redrawn when the second one is plotted it would be great.
import sys
import random
import matplotlib
matplotlib.use('Qt5Agg')
from PyQt6 import QtCore, QtWidgets
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
class Canvas(FigureCanvas):
def __init__(self,fig):
self.paint_enabled = True
super().__init__(fig)
self.installEventFilter(self)
def eventFilter(self, object, event):
if object == self and event.type() == QtCore.QEvent.Type.Paint and not self.paint_enabled:
return False
return super().eventFilter(object,event)
app = QtWidgets.QApplication(sys.argv)
w = QtWidgets.QMainWindow()
fig = Figure(figsize=(5, 4), dpi=100)
ax = fig.add_subplot(111)
xdata = list(range(50))
ydata = [random.randint(0, 10) for i in range(50)]
ax.plot(xdata,ydata)
c1 = Canvas(fig)
c1.move(100,100)
c1.draw()
c1.show()
c1.paint_enabled = False
def second_plot():
ydata = [random.randint(0, 10) for i in range(50)]
ax.clear()
ax.plot(xdata,ydata)
c2 = Canvas(fig)
c2.move(600,600)
c2.draw()
c2.show()
timer = QtCore.QTimer()
timer.setSingleShot(True)
timer.timeout.connect(second_plot)
timer.start(1000)
app.exec()
I'm trying to draw a region of interest on a color map that is embedded in a pyqt5 gui. This is an example of what I want.
import sys
from PyQt5.QtWidgets import (QWidget, QPushButton,
QHBoxLayout, QVBoxLayout, QApplication)
from PyQt5 import QtCore
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
import ROI_class as roi # ROI_class.py
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
self.drawButton.clicked.connect(self.draw_map_Callback)
self.roiButton.clicked.connect(self.choose_roi)
def initUI(self):
self.drawButton = QPushButton("draw map")
self.roiButton = QPushButton("roi")
self.hbox = QHBoxLayout()
self.hbox.addStretch(1)
self.hbox.addWidget(self.drawButton)
self.hbox.addWidget(self.roiButton)
self.vbox = QVBoxLayout()
self.vbox.addStretch(1)
self.vbox.addLayout(self.hbox)
self.setLayout(self.vbox)
self.setGeometry(500, 500, 500, 500)
self.setWindowTitle('ROI')
self.show()
def draw_map_Callback(self):
img = np.ones((100, 100)) * range(0, 100)
fig, ax1 = plt.subplots()
self.con_canvas = FigureCanvas(plt.figure(tight_layout=True))
self.con_canvas.setFocusPolicy(QtCore.Qt.ClickFocus)
self.con_canvas.setFocus()
self.con_toolbar = NavigationToolbar(self.con_canvas, self)
self.vbox.addWidget(self.con_toolbar)
self.vbox.addWidget(self.con_canvas)
self._con_ax = self.con_canvas.figure.subplots()
self.con_img = self._con_ax.imshow(img, cmap ='jet')
self._con_ax.set_xlabel('xlabel')
self._con_ax.set_ylabel('ylabel')
self.con_cbar = self.con_canvas.figure.colorbar(self.con_img)
self._con_ax.set_aspect('equal')
def choose_roi(self):
y = roi.new_ROI(self.con_img)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
It will draw a colormap when I click "draw map". Then I want it to allow me to draw a region of interest with my mouse and get a mask using the code on this link below.
https://github.com/martindurant/misc/blob/master/ROI.py
The "ROI_class" that is imported is just a copy and paste of the code in the link above.
I can successfully draw the plot on the GUI but when I click "roi", it doesn't allow me to draw the region of interest.
When I mad a new file and paste the code in the link above with something like
fig, ax1 = plt.subplots()
s = ax1.imshow(img, cmap ='jet')
ax1.set_xlabel('subcolor')
ax1.set_ylabel('ylabel')
y = new_ROI(s)
at the end of the code, it worked just fine and I was able to draw the region of interest and get the mask of it.
But when I try to do this in the GUI, it wouldn't let me draw the region of interest. I'm very confused why this isn't working.
The problem is that picker (the variable "y") is a local variable that gets destroyed instantly causing the desired behavior not to be executed. The solution is to make it an attribute of the class:
self.y = roi.new_ROI(self.con_img)
I am not an experienced programmer and i am trying to create a sort of datalogger program in python using Qt for python (PySide2) to build the GUI. I was able to create a gui using Designer and the load it inside python. The gui is only a blank window for now. Then i created a function that launch MatplotLib in a window showing a graph, and i updtate data in each loop of the main program, using a Qt timer.
Everithing works, but the redraw time of MatPlotLib slow down the gui refresh too much. So I tried to put MatPlotLib inside a separe Thread, and after a lot of trials i understood it cannot run in a separate Thread..
At the end i decided to try with Multiprocessing. Now the MatPlotLib runs fine in a separate Process ( i use queue to send data to MatPlotLib) and exit properly after the process is finished, but when i close the main window the program newer close completely, and also typing Ctrl+C the prompt is blocked.
This is my code:
#!/usr/bin/env python3
import sys
from PySide2.QtUiTools import QUiLoader
from PySide2.QtWidgets import QApplication, QWidget
from PySide2.QtCore import QFile, QTimer
import matplotlib.pyplot as plt
from multiprocessing import Process, Queue, freeze_support
import random
class DSL(QWidget):
def __init__(self):
# LOAD HMI
QWidget.__init__(self)
designer_file = QFile('userInterface.ui')
designer_file.open(QFile.ReadOnly)
loader = QUiLoader()
self.ui = loader.load(designer_file, self)
designer_file.close()
self.ui.show()
# Data to be visualized
self.data = []
def mainLoop(self):
self.data = []
for i in range(10):
self.data.append(random.randint(0, 10))
# Send data to graph process
queue.put(self.data)
# LOOP repeater
QTimer.singleShot(10, self.mainLoop)
def graphProcess(queue):
for i in range(10):
# Get data
data = queue.get()
# MatPlotLib
plt.ion()
plt.clf()
plt.plot(data)
plt.show()
plt.pause(0.1)
print('process end')
if __name__ == '__main__':
# MatPlotLib Process
queue = Queue()
freeze_support()
p = Process(target=graphProcess, args=(queue,))
p.daemon = True
p.start()
# PySide2 Process
app = QApplication(sys.argv)
dsl = DSL()
dsl.mainLoop()
sys.exit(app.exec_())
Instead of using matplotlib in a secondary process it is better to embed a canvas in a QWidget that allows it to run in the same PySide2 processes:
#!/usr/bin/env python3
import sys
from PySide2.QtCore import QFile, QObject, Signal, Slot, QTimer
from PySide2.QtWidgets import QApplication, QVBoxLayout, QWidget
from PySide2.QtUiTools import QUiLoader
import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
import random
class DSL(QObject):
dataChanged = Signal(list)
def __init__(self, parent=None):
# LOAD HMI
super().__init__(parent)
designer_file = QFile("userInterface.ui")
if designer_file.open(QFile.ReadOnly):
loader = QUiLoader()
self.ui = loader.load(designer_file)
designer_file.close()
self.ui.show()
# Data to be visualized
self.data = []
def mainLoop(self):
self.data = []
for i in range(10):
self.data.append(random.randint(0, 10))
# Send data to graph
self.dataChanged.emit(self.data)
# LOOP repeater
QTimer.singleShot(10, self.mainLoop)
class MatplotlibWidget(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
fig = Figure(figsize=(7, 5), dpi=65, facecolor=(1, 1, 1), edgecolor=(0, 0, 0))
self.canvas = FigureCanvas(fig)
self.toolbar = NavigationToolbar(self.canvas, self)
lay = QVBoxLayout(self)
lay.addWidget(self.toolbar)
lay.addWidget(self.canvas)
self.ax = fig.add_subplot(111)
self.line, *_ = self.ax.plot([])
#Slot(list)
def update_plot(self, data):
self.line.set_data(range(len(data)), data)
self.ax.set_xlim(0, len(data))
self.ax.set_ylim(min(data), max(data))
self.canvas.draw()
if __name__ == "__main__":
app = QApplication(sys.argv)
dsl = DSL()
dsl.mainLoop()
matplotlib_widget = MatplotlibWidget()
matplotlib_widget.show()
dsl.dataChanged.connect(matplotlib_widget.update_plot)
sys.exit(app.exec_())
My goal is to identify which subplot has been clicked on by the user. More precisely in the matplotlib class, I can identify the subplot using event.inaxes. Great. But I cannot get that event in the Qt widget class.
I am definitely missing something ...
Here is the code with my latest "awkward" attempt. Any suggestion on how to procceed ?
I am no Python expert. Python 2.7 has to be used (no choice)
from __future__ import print_function
from __future__ import division
import sys
from PyQt4 import QtGui
from PyQt4 import QtCore
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from matplotlib.figure import Figure
from matplotlib.backend_bases import key_press_handler
from matplotlib.backend_bases import Event
from matplotlib.backends.backend_qt4agg import (
FigureCanvasQTAgg as FigureCanvas,
NavigationToolbar2QT as NavigationToolbar)
#Connect InventoryChartsWidget to ChartFigure: QT
class TheConnector(QtCore.QObject):
selecteddataregion=pyqtSignal(name='selecteddataregion')
def emitsignal(self,xmin,xmax,ymin,ymax):
self.selecteddataregion.emit()
#Chart including events: MATPLOTLIB
class ChartFigure(Figure):
def onclick(self,event):
#MAIN ISSUE
#HOW TO RETURN THE subplot axes to class InventoryChartsWidget?
if event.button==1 :
self.ConnSbPlt.emitsignal(1.0,1.0,2.0,2.0)
print('OK: Axes is ... ', event.inaxes)
def __init__(self,Conn):
#Init the Matplotlib
Figure.__init__(self) #initialize the orginal class, see also super()
super(ChartFigure, self).__init__()
self.canvas=FigureCanvas(self)
self.ConnSbPlt=Conn
#Chart including events: QT
class InventoryChartsWidget(QtGui.QDialog):
def __init__(self, parent=None,xlimlow=0,xlimhigh=100,ylimlow=0,ylimhigh=100, G_array=[], N_array=[], ddom_array=[], hdom_array=[], speciesDict={}):
QMainWindow.__init__(self, parent)
#Fake stupid data
self.mG_array = [2] * 10
self.mHdom_array = [0.5] * 10
#jte to make sur I have it
self.xdata_start=-1.0
#fake plot to get a member of type subplot: UGLY!
#Attempt to create a member object "axes"
self.tabFake = QtGui.QWidget()
self.tabFake = self.create_tab(self.tabFake)
self.tabFake.plots = []
self.subPlotFake = self.tabFake.fig.add_subplot(111)
print("here is OK; it exists ...", self.subPlotFake)
self.create_main_frame()
self.setModal(False)
self.setVisible(True)
self.show()
def create_main_frame(self):
#Associate a Qwidget with the InventoryChartsWidget widget
print("OK here too; it exists ... ",self.subPlotFake)
self.main_frame = QtGui.QWidget()
LesTabs = QtGui.QTabWidget()
self.tabG = QtGui.QWidget()
#Fill the tab with Matplotlib object and draw the charts
self.tabG=self.create_tab(self.tabG)
self.on_draw_G(self.tabG)
self.tabG.fig.subplots_adjust(left=0.02,bottom=0.05,right=1,top=0.95,wspace=0.2,hspace=0.2)
LesTabs.addTab(self.tabG,"Chart")
grid = QGridLayout()
grid.addWidget(LesTabs, 0, 0)
self.main_frame.setLayout(grid)
self.setLayout(grid)
self.layout().addWidget(self.main_frame)
def UpdatePlot_DataSelection(self):
#SLOT
print("Get connected here process the data in the subplot XX...")
def on_draw_G(self,tab):
#Juts one subplot for test purpose
tab.fig.clear()
tab.plots = []
subPlot = tab.fig.add_subplot(111)
subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
subPlot = tab.fig.add_subplot(122)
subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
tab.canvas.draw()
def create_tab(self,tab):
#Create the tab widget, associated with Matplotlib plot
print("OK member exists ... ", self.xdata_start)
print("OK member exists ",self.tabFake)
#ISSUE HERE: don't understand
#print("NOT OK !!! member does not exist Why ? ",self.subPlotFake)
Conn=TheConnector()
#MATPLOTLIB
tab.fig = ChartFigure(Conn)
tab.canvas = FigureCanvas(tab.fig)
tab.canvas.setParent(tab)
tab.canvas.setFocusPolicy(Qt.StrongFocus)
tab.canvas.setFocus()
#connect signal to slot
Conn.selecteddataregion.connect(self.UpdatePlot_DataSelection)
tab.mpl_toolbar = NavigationToolbar(tab.canvas, tab)
vbox = QVBoxLayout()
vbox.addWidget(tab.canvas)
vbox.addWidget(tab.mpl_toolbar)
tab.setLayout(vbox)
tab.canvas.mpl_connect('button_press_event', tab.fig.onclick)
return tab
def on_key_press(self, event):
#Keyboard input: standard mpl key press
key_press_handler(event, self.canvas, self.mpl_toolbar)
def PlotData_G(self, plot, G_array, hdom_array):
# Plot G
plot.hold(False)
plot.scatter(x=hdom_array, y=G_array, marker='+',linewidths=1.5)
plot.set_autoscaley_on(True)
plot.tick_params(labelsize=8)
def main():
app = QApplication(sys.argv)
form = InventoryChartsWidget(xlimlow=0,xlimhigh=60,ylimlow=0,ylimhigh=80)
form.show()
app.exec_()
if __name__ == "__main__":
main()
There are 3 classes:
TheConnector is a Signal/Slot QT class
ChartFigure is matplotlib class (including the desired mouse Event)
InventoryChartsWidget is the main widget (Qt; here I need the ID of the subplot)
Any help would be greatly appreciated. Thank you.
Here is a working solution. The true limit was my thinking in python (to be more specific the lack of properly declared variables ... can't get use to it)
from __future__ import print_function
from __future__ import division
import sys
from PyQt4 import QtGui
from PyQt4 import QtCore
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from matplotlib.figure import Figure
from matplotlib.backend_bases import key_press_handler
from matplotlib.backend_bases import Event
from matplotlib.backends.backend_qt4agg import (
FigureCanvasQTAgg as FigureCanvas,
NavigationToolbar2QT as NavigationToolbar)
#Connect InventoryChartsWidget to ChartFigure: QT
class TheConnector(QtCore.QObject):
selecteddataregionARG=pyqtSignal(object,name='selecteddataregionIN')
def emitsignalEvent(self,TheEvent):
self.selecteddataregionARG.emit(TheEvent)
#Chart including events: MATPLOTLIB
class ChartFigure(Figure):
def onclick(self,event):
#MAIN ISSUE
#HOW TO RETURN THE subplot axes to class InventoryChartsWidget class?
if event.button==1 :
print('Event: Axes is ... ', event.inaxes)
self.ConnSbPlt.emitsignalEvent(event.inaxes)
def __init__(self,Conn):
#Init the Matplotlib
Figure.__init__(self) #initialize the orginal class, see also super()
super(ChartFigure, self).__init__()
self.canvas=FigureCanvas(self)
self.ConnSbPlt=Conn
#Chart including events: QT
class InventoryChartsWidget(QtGui.QDialog):
def __init__(self, parent=None,xlimlow=0,xlimhigh=100,ylimlow=0,ylimhigh=100, G_array=[], N_array=[], ddom_array=[], hdom_array=[], speciesDict={}):
QMainWindow.__init__(self, parent)
#Fake stupid data
self.mG_array = [2] * 10
self.mHdom_array = [0.5] * 10
#jte to make sur I have it
self.xdata_start=-1.0
self.create_main_frame()
self.setModal(False)
self.setVisible(True)
self.show()
def create_main_frame(self):
#Associate a Qwidget with the InventoryChartsWidget widget
self.main_frame = QtGui.QWidget()
LesTabs = QtGui.QTabWidget()
self.tabG = QtGui.QWidget()
#Fill the tab with Matplotlib object and draw the charts
self.tabG=self.create_tab(self.tabG)
self.on_draw_G(self.tabG)
self.tabG.fig.subplots_adjust(left=0.02,bottom=0.05,right=1,top=0.95,wspace=0.2,hspace=0.2)
LesTabs.addTab(self.tabG,"Chart")
grid = QGridLayout()
grid.addWidget(LesTabs, 0, 0)
self.main_frame.setLayout(grid)
self.setLayout(grid)
self.layout().addWidget(self.main_frame)
def UpdatePlot_DataSelection_withArg(self,TheEvent):
#SLOT
print("WITH ARG : Get connected here process the data in the subplot XX...",TheEvent)
def on_draw_G(self,tab):
#Juts one subplot for test purpose
tab.fig.clear()
tab.plots = []
subPlot = tab.fig.add_subplot(111)
subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
subPlot = tab.fig.add_subplot(122)
subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
tab.canvas.draw()
def create_tab(self,tab):
#Create the tab widget, associated with Matplotlib plot
Conn=TheConnector()
#MATPLOTLIB
tab.fig = ChartFigure(Conn)
tab.canvas = FigureCanvas(tab.fig)
tab.canvas.setParent(tab)
tab.canvas.setFocusPolicy(Qt.StrongFocus)
tab.canvas.setFocus()
#connect signal to slot
Conn.selecteddataregionARG.connect(lambda who="Three": self.UpdatePlot_DataSelection_withArg(who))
tab.mpl_toolbar = NavigationToolbar(tab.canvas, tab)
vbox = QVBoxLayout()
vbox.addWidget(tab.canvas)
vbox.addWidget(tab.mpl_toolbar)
tab.setLayout(vbox)
tab.canvas.mpl_connect('button_press_event', tab.fig.onclick)
return tab
def on_key_press(self, event):
#Keyboard input: standard mpl key press
key_press_handler(event, self.canvas, self.mpl_toolbar)
def PlotData_G(self, plot, G_array, hdom_array):
# Plot G
plot.hold(False)
plot.scatter(x=hdom_array, y=G_array, marker='+',linewidths=1.5)
plot.set_autoscaley_on(True)
def main():
app = QApplication(sys.argv)
form = InventoryChartsWidget(xlimlow=0,xlimhigh=60,ylimlow=0,ylimhigh=80)
form.show()
app.exec_()
if __name__ == "__main__":
main()
Maybe it can help someone ...
We can of course argue if the 3 classes make sense but this is another topic.
Here is how you could transfer the event to the main class:
from __future__ import print_function
from __future__ import division
import sys
from PyQt4 import QtGui
from PyQt4 import QtCore
from matplotlib.figure import Figure
from matplotlib.backend_bases import key_press_handler
from matplotlib.backends.backend_qt4agg import (
FigureCanvasQTAgg as FigureCanvas,
NavigationToolbar2QT as NavigationToolbar)
#Connect InventoryChartsWidget to ChartFigure: QT
class TheConnector(QtCore.QObject):
selecteddataregion=QtCore.pyqtSignal(object, name='selecteddataregion')
def emitsignal(self,xmin,xmax,ymin,ymax, event):
self.selecteddataregion.emit((xmin,xmax,ymin,ymax, event))
#Chart including events: MATPLOTLIB
class ChartFigure(Figure):
def onclick(self,event):
#MAIN ISSUE
#HOW TO RETURN THE subplot axes to class InventoryChartsWidget?
if event.button==1 :
print('OK: Axes is ... ', event.inaxes)
self.ConnSbPlt.emitsignal(1.0,1.0,2.0,2.0, event)
def __init__(self,Conn):
#Init the Matplotlib
Figure.__init__(self) #initialize the orginal class, see also super()
super(ChartFigure, self).__init__()
self.canvas=FigureCanvas(self)
self.ConnSbPlt=Conn
#Chart including events: QT
class InventoryChartsWidget(QtGui.QDialog):
def __init__(self, parent=None,xlimlow=0,xlimhigh=100,ylimlow=0,ylimhigh=100, G_array=[], N_array=[], ddom_array=[], hdom_array=[], speciesDict={}):
QtGui.QMainWindow.__init__(self, parent)
#Fake stupid data
self.mG_array = [2] * 10
self.mHdom_array = [0.5] * 10
#jte to make sur I have it
self.xdata_start=-1.0
#fake plot to get a member of type subplot: UGLY!
#Attempt to create a member object "axes"
self.tabFake = QtGui.QWidget()
self.tabFake = self.create_tab(self.tabFake)
self.tabFake.plots = []
self.subPlotFake = self.tabFake.fig.add_subplot(111)
print("here is OK; it exists ...", self.subPlotFake)
self.create_main_frame()
self.setModal(False)
self.setVisible(True)
self.show()
def create_main_frame(self):
#Associate a Qwidget with the InventoryChartsWidget widget
print("OK here too; it exists ... ",self.subPlotFake)
self.main_frame = QtGui.QWidget()
LesTabs = QtGui.QTabWidget()
self.tabG = QtGui.QWidget()
#Fill the tab with Matplotlib object and draw the charts
self.tabG=self.create_tab(self.tabG)
self.on_draw_G(self.tabG)
self.tabG.fig.subplots_adjust(left=0.02,bottom=0.05,right=1,top=0.95,wspace=0.2,hspace=0.2)
LesTabs.addTab(self.tabG,"Chart")
grid = QtGui.QGridLayout()
grid.addWidget(LesTabs, 0, 0)
self.main_frame.setLayout(grid)
self.setLayout(grid)
self.layout().addWidget(self.main_frame)
def UpdatePlot_DataSelection(self, transfer_object):
#SLOT
xmin,xmax,ymin,ymax, event = transfer_object
print ("Axes are now in the InventoryChartsWidget: ", event.inaxes)
def on_draw_G(self,tab):
#Juts one subplot for test purpose
tab.fig.clear()
tab.plots = []
subPlot = tab.fig.add_subplot(111)
#subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
subPlot = tab.fig.add_subplot(122)
#subPlot.hold(False)
tab.plots.append(subPlot)
self.PlotData_G(subPlot,self.mG_array,self.mHdom_array)
tab.canvas.draw()
def create_tab(self,tab):
#Create the tab widget, associated with Matplotlib plot
print("OK member exists ... ", self.xdata_start)
print("OK member exists ",self.tabFake)
#ISSUE HERE: don't understand
#print("NOT OK !!! member does not exist Why ? ",self.subPlotFake)
# reason: self.subPlotFake does not yet exist
Conn=TheConnector()
#MATPLOTLIB
tab.fig = ChartFigure(Conn)
tab.canvas = FigureCanvas(tab.fig)
tab.canvas.setParent(tab)
tab.canvas.setFocusPolicy(QtCore.Qt.StrongFocus)
tab.canvas.setFocus()
#connect signal to slot
Conn.selecteddataregion.connect(self.UpdatePlot_DataSelection)
tab.mpl_toolbar = NavigationToolbar(tab.canvas, tab)
vbox = QtGui.QVBoxLayout()
vbox.addWidget(tab.canvas)
vbox.addWidget(tab.mpl_toolbar)
tab.setLayout(vbox)
tab.canvas.mpl_connect('button_press_event', tab.fig.onclick)
return tab
def on_key_press(self, event):
#Keyboard input: standard mpl key press
key_press_handler(event, self.canvas, self.mpl_toolbar)
def PlotData_G(self, plot, G_array, hdom_array):
# Plot G
#plot.hold(False) #axes.hold is deprecated.
plot.scatter(x=hdom_array, y=G_array, marker='+',linewidths=1.5)
plot.set_autoscaley_on(True)
plot.tick_params(labelsize=8)
def main():
app = QtGui.QApplication(sys.argv)
form = InventoryChartsWidget(xlimlow=0,xlimhigh=60,ylimlow=0,ylimhigh=80)
form.show()
app.exec_()
if __name__ == "__main__":
main()
Starting with the working Matplotlib animation code shown below, my goal is to embed this animation (which is just a circle moving across the screen) within a PyQT4 GUI.
import matplotlib.pyplot as plt
from matplotlib.patches import Circle
from matplotlib import animation
fig,ax = plt.subplots()
ax.set_aspect('equal','box')
circle = Circle((0,0), 1.0)
ax.add_artist(circle)
ax.set_xlim([0,10])
ax.set_ylim([-2,2])
def animate(i):
circle.center=(i,0)
return circle,
anim = animation.FuncAnimation(fig,animate,frames=10,interval=100,repeat=False,blit=True)
plt.show()
I am able to accomplish this using the following code, but there is one hitch: I cannot get blitting to work.
import sys
from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.patches import Circle
from matplotlib import animation
class Window(QtGui.QDialog): #or QtGui.QWidget ???
def __init__(self):
super(Window, self).__init__()
self.fig = Figure(figsize=(5,4),dpi=100)
self.canvas = FigureCanvas(self.fig)
self.ax = self.fig.add_subplot(111) # create an axis
self.ax.hold(False) # discards the old graph
self.ax.set_aspect('equal','box')
self.circle = Circle((0,0), 1.0)
self.ax.add_artist(self.circle)
self.ax.set_xlim([0,10])
self.ax.set_ylim([-2,2])
self.button = QtGui.QPushButton('Animate')
self.button.clicked.connect(self.animate)
# set the layout
layout = QtGui.QVBoxLayout()
layout.addWidget(self.canvas)
layout.addWidget(self.button)
self.setLayout(layout)
def animate(self):
self.anim = animation.FuncAnimation(self.fig,self.animate_loop,frames=10,interval=100,repeat=False,blit=False)
self.canvas.draw()
def animate_loop(self,i):
self.circle.center=(i,0)
return self.circle,
def main():
app = QtGui.QApplication(sys.argv)
ex = Window()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
When I set blit=True, after pressing the Animate button I get the following error:
a.figure.canvas.restore_region(bg_cache[a])
KeyError: matplotlib.axes._subplots.AxesSubplot object at 0x00000000095F1D30
In searching this error, I find many posts about how blitting does not work on Macs, but I am using Windows 7. I have tried replacing self.canvas.draw() with self.canvas.update(), but this does not work.
After looking at the source code of the animation module, I realized that there is an error in the Animation class (the dictionary bg_cache is empty, when it is accessed for the first time with blitting switched on).
This is fixed in the git version of matplotlib; however, in the most recent stable version 1.5.1, the bug is still present. You can either fix the bug in the matplotlib code itself or you can make a subclass to FuncAnimation. I chose that way, because it should still work after updating matplotlib.
from matplotlib import animation
class MyFuncAnimation(animation.FuncAnimation):
"""
Unfortunately, it seems that the _blit_clear method of the Animation
class contains an error in several matplotlib verions
That's why, I fork it here and insert the latest git version of
the function.
"""
def _blit_clear(self, artists, bg_cache):
# Get a list of the axes that need clearing from the artists that
# have been drawn. Grab the appropriate saved background from the
# cache and restore.
axes = set(a.axes for a in artists)
for a in axes:
if a in bg_cache: # this is the previously missing line
a.figure.canvas.restore_region(bg_cache[a])
Then, simpy use MyFuncAnimation instead of animation.FuncAnimation.
Took me a while to figure it out, but I hope it helps anybody.
After some time I managed to recreate the animation by using the underlying functions directly and not using the animation wrapper:
import sys
from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.patches import Circle
from matplotlib import animation
from time import sleep
class Window(QtGui.QDialog): #or QtGui.QWidget ???
def __init__(self):
super(Window, self).__init__()
self.fig = Figure(figsize=(5, 4), dpi=100)
self.canvas = FigureCanvas(self.fig)
self.ax = self.fig.add_subplot(111) # create an axis
self.ax.hold(False) # discards the old graph
self.ax.set_aspect('equal', 'box')
self.circle = Circle((0,0), 1.0, animated=True)
self.ax.add_artist(self.circle)
self.ax.set_xlim([0, 10])
self.ax.set_ylim([-2, 2])
self.button = QtGui.QPushButton('Animate')
self.button.clicked.connect(self.animate)
# set the layout
layout = QtGui.QVBoxLayout()
layout.addWidget(self.canvas)
layout.addWidget(self.button)
self.setLayout(layout)
self.canvas.draw()
self.ax_background = self.canvas.copy_from_bbox(self.ax.bbox)
def animate(self):
self.animate_loop(0)
def animate_loop(self,begin):
for i in range(begin,10):
self.canvas.restore_region(self.ax_background)
self.circle.center=(i,0)
self.ax.draw_artist(self.circle)
self.canvas.blit(self.ax.bbox)
self.canvas.flush_events()
sleep(0.1)
def main():
app = QtGui.QApplication(sys.argv)
ex = Window()
ex.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
Maybe this will be of use to you.