I'm not certain, but I believe you're running into this:
https://doc.qt.io/qt-5/threads-qobject.html#qobject-reentrancy
The following is a minor change from the code you have and it should work.
Instead of updating the PlotDataItem directly from the thread, emit a
signal from the thread and connect it to the PlotDataItem.setData method.
That would then run on the main thread so the object is kept alive.
import sys
import time
from PySide2 import QtGui, QtCore
import pyqtgraph as pg
import numpy as np
from PySide2.QtCore import QThread
app = QtGui.QApplication([])
w = pg.PlotWidget()
class Worker(QThread):
sigUpdated = QtCore.Signal(object)
def __init__(self, plotdata: pg.PlotDataItem):
QThread.__init__(self)
self.plotdata = plotdata
self.sigUpdated.connect(self.plotdata.setData)
self.raw_data = []
def run(self):
for i in range(1, 10001):
newdata = np.random.normal(loc=10,scale=2)
self.raw_data.append((time.time(),newdata))
data = np.array(self.raw_data)
self.sigUpdated.emit(data)
time.sleep(0.01)
plotdata = w.plot(x=[],y=[])
w.show()
worker = Worker(plotdata)
worker.start()
sys.exit(app.exec_())
On Thursday, March 26, 2020 at 7:56:32 AM UTC-7, Daniel Thiem wrote:
>
> Hi,
>
> I am running a plot in an Application where I add data regularly. After a
> certain time I get the following error:
>
> Traceback (most recent call last):
> File
> "D:\Programs\Miniconda3\envs\FreezingQtApp\lib\site-packages\pyqtgraph\graphicsItems\ViewBox\ViewBox.py"
> , line 75, in boundingRect
> return self.mapRectFromParent(self.parentItem().boundingRect())
> RuntimeError: Internal C++ object (ChildGroup) already deleted.
> Traceback (most recent call last):
> File "C:/Users/xxxx/.PyCharm2019.2/config/scratches/scratch.py", line 27
> , in run
> self.plotdata.setData(data)
> File
> "D:\Programs\Miniconda3\envs\FreezingQtApp\lib\site-packages\pyqtgraph\graphicsItems\PlotDataItem.py"
> , line 466, in setData
> self.updateItems()
> File
> "D:\Programs\Miniconda3\envs\FreezingQtApp\lib\site-packages\pyqtgraph\graphicsItems\PlotDataItem.py"
> , line 492, in updateItems
> self.curve.setData(x=x, y=y, **curveArgs)
> File
> "D:\Programs\Miniconda3\envs\FreezingQtApp\lib\site-packages\pyqtgraph\graphicsItems\PlotCurveItem.py"
> , line 335, in setData
> self.updateData(*args, **kargs)
> File
> "D:\Programs\Miniconda3\envs\FreezingQtApp\lib\site-packages\pyqtgraph\graphicsItems\PlotCurveItem.py"
> , line 369, in updateData
> self.prepareGeometryChange()
> RuntimeError: Internal C++ object (PlotCurveItem) already deleted.
>
> I've broken the code down to the minimal example:
>
> import sys
> import time
> from PySide2 import QtGui, QtCore
>
> import pyqtgraph as pg
> import numpy as np
>
> from PySide2.QtCore import QThread
>
>
>
> app = QtGui.QApplication([])
> w = pg.PlotWidget()
>
> class Worker(QThread):
>
> def __init__(self, plotdata: pg.PlotDataItem):
> QThread.__init__(self)
> self.plotdata = plotdata
> self.raw_data = []
>
> def run(self):
> for i in range(1, 10001):
> newdata = np.random.normal(loc=10,scale=2)
> self.raw_data.append((time.time(),newdata))
> data = np.array(self.raw_data)
> self.plotdata.setData(data)
> time.sleep(0.01)
>
> plotdata = w.plot(x=[],y=[])
> w.show()
>
> worker = Worker(plotdata)
> worker.start()
>
>
> sys.exit(app.exec_())
>
>
> I just don't know where I could have released an object that is now being
> deleted by the gc.
>
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