【发布时间】:2015-03-27 21:45:46
【问题描述】:
我正在 pyqtgraph 中绘制通过 UDP 接收的实时数据。每次更新 2048 点时,一切都很好,但是在 4096 或 8k 点时,只要我尝试调整大小或放大,绘图就会冻结。如果我切换 logY 比例,更新会恢复。我已验证 UDP 流中没有间隙。也试过用
# p.setDownsampling(auto=True)
# p.setClipToView(True)
选项,但它们没有帮助
我读到 pyqtgraph 可以处理比这更多的数据,所以我有点困惑。问题可以看这里:https://www.youtube.com/watch?v=iL-WHEbSx-w
这里是代码,我直接从示例中获取了它,只是做了一些小的改动
from pyqtgraph.Qt import QtGui, QtCore
import numpy as np
import pyqtgraph as pg
from pyqtgraph.ptime import time
from struct import pack, unpack
from socket import *
app = QtGui.QApplication([])
data = []
p = pg.plot(fillLevel=20)
p.setWindowTitle('pyqtgraph example: PlotSpeedTest')
p.setRange(QtCore.QRectF(0, 0, 30720000, 10 ))
p.setLabel('bottom', 'Frequency', units='Hz')
p.showGrid(True, True)
fScale = np.linspace(0, 30720000, 8192)
# p.setDownsampling(auto=True)
# p.setClipToView(True)
curve = p.plot()
# Receive UDP packets transmitted by a broadcasting service
sock = socket(AF_INET, SOCK_DGRAM)
try:
sock.bind(('', 1234))
except:
print "Error connecting to the UDP stream."
quit
ptr = 0
lastTime = time()
fps = None
def update():
global sock, fScale
global curve, data, ptr, p, lastTime, fps
stream = sock.recv(16384)
if (len(stream) == 16384):
data_float16 = np.fromstring(stream, dtype=np.float16)
data = data_float16.astype(np.float32)
print "got data", lastTime, "\n"
# print data
curve.setData(fScale,data,_callSync='off')
# curve.setData(data,_callSync='off')
now = time()
dt = now - lastTime
lastTime = now
if fps is None:
fps = 1.0/dt
else:
s = np.clip(dt*3., 0, 1)
fps = fps * (1-s) + (1.0/dt) * s
p.setTitle('%0.2f fps' % fps)
app.processEvents() ## force complete redraw for every plot
timer = QtCore.QTimer()
timer.timeout.connect(update)
timer.start(0)
## Start Qt event loop unless running in interactive mode.
if __name__ == '__main__':
import sys
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
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