本文介紹了如何使用pyqtgraph TimeAxisItem使X軸時間動態刷新的處理方法，對大家解決問題具有一定的參考價值，需要的朋友們下面隨著小編來一起學習吧！
問題描述
我將根據一系列數據制作實時曲線.首先，我建立了一個數量字典，里面有 3 組數據.當前程序可以動態繪制曲線.X軸也可以顯示時間，也是實時更新的.但是，X 軸上不同點的時間始終是相同的值.
I'm going to make a real-time curve out of a sequence of data. First, I established a quantity dictionary, which has 3 groups of data. The current program can draw a curve dynamically. The X-axis can also show the time, which is also updated in real time. However, the time at different points in the X-axis is always the same value.
UNIX_EPOCH_naive = datetime.datetime(1970, 1, 1, 0, 0) #offset-naive datetime
UNIX_EPOCH_offset_aware = datetime.datetime(1970, 1, 1, 0, 0, tzinfo = pytz.utc) #offset-aware datetime
UNIX_EPOCH = UNIX_EPOCH_naive
TS_MULT_us = 1e6
def now_timestamp(ts_mult=TS_MULT_us, epoch=UNIX_EPOCH):
return(int((datetime.datetime.utcnow() - epoch).total_seconds()*ts_mult))
def int2dt(ts, ts_mult=TS_MULT_us):
tz = pytz.timezone('Asia/Shanghai')
user_ts = int(time.time())
d1 = datetime.datetime.fromtimestamp(float(user_ts))
d1x = tz.localize(d1)
return(d1x)
def dt2int(dt, ts_mult=TS_MULT_us, epoch=UNIX_EPOCH):
delta = dt - epoch
return(int(delta.total_seconds()*ts_mult))
def td2int(td, ts_mult=TS_MULT_us):
return(int(td.total_seconds()*ts_mult))
def int2td(ts, ts_mult=TS_MULT_us):
return(datetime.timedelta(seconds=float(ts)/ts_mult))
class TimeAxisItem(pg.AxisItem):
def __init__(self, *args, **kwargs):
super(TimeAxisItem, self).__init__(*args, **kwargs)
def tickStrings(self, values, scale, spacing):
return [int2dt(value).strftime("%H:%M:%S") for value in values]
p = win.addPlot(title="Data-Time Graph", axisItems={'bottom': TimeAxisItem(orientation='bottom')})
data_dict = {}
p.addLegend()
data_x=[]
def getDate():
......
.....
curve = p.plot(pen = color[len(data_dict)],name=name)
data_dict[name] = [curve] # dictionary: {key:[curve,[dadta1,data2,...]]}
data_dict[name].append([val])
def addToDisplay():
p.plot()
for i in data_dict.items():
data = i[1][1] #
curve = i[1][0] #
if(len(data) > data_frequency):#
data_y=data[- data_frequency:]
else:
data_y = data[:]
curve.setData(data_y)#
if __name__ == "__main__":
th= threading.Thread(target=getDate)#
th.start()
timer = pg.QtCore.QTimer()
timer.timeout.connect(addToDisplay)
timer.start(10)
我希望X軸是動態刷新的，右邊是最近的時間，左邊是過去的時間.
What I hope is that the X-axis is dynamically refreshed, with the latest time on the right side and the past time is on the left side.
推薦答案
我不完全確定您想要實現什么，因為您的代碼沒有運行，但您似乎正在嘗試創建時間戳圖.這是一個使用 TimeAxisItem 來跟蹤 X 軸上經過的時間的小部件.
I'm not entirely sure what you're trying to achieve since your code doesn't run but it seems you're trying to create a timestamp plot. Here's a widget that uses TimeAxisItem to keep track of elapsed time on the X-axis.
PyQt5
from PyQt5 import QtCore, QtGui, QtWidgets
from threading import Thread
from collections import deque
import pyqtgraph as pg
import numpy as np
import random
import sys
import time
"""Scrolling Timestamp Plot Widget Example"""
class TimeAxisItem(pg.AxisItem):
"""Internal timestamp for x-axis"""
def __init__(self, *args, **kwargs):
super(TimeAxisItem, self).__init__(*args, **kwargs)
def tickStrings(self, values, scale, spacing):
"""Function overloading the weak default version to provide timestamp"""
return [QtCore.QTime().currentTime().addMSecs(value).toString('mm:ss') for value in values]
class ScrollingTimestampPlot(QtGui.QWidget):
"""Scrolling plot widget with timestamp on x-axis and dynamic y-axis"""
def __init__(self, parent=None):
super(ScrollingTimestampPlot, self).__init__(parent)
# Internal timestamp for x-axis
self.timestamp = QtCore.QTime()
self.timestamp.start()
# Desired Frequency (Hz) = 1 / self.FREQUENCY
# USE FOR TIME.SLEEP (s)
self.FREQUENCY = 0.025
# Screen refresh rate to update plot (ms)
# self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE = 1 / Desired Frequency (Hz) * 1000
# USE FOR TIMER.TIMER (ms)
self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE = self.FREQUENCY * 1000
self.DATA_POINTS_TO_DISPLAY = 200
# Automatically pops from left if length is full
self.data = deque(maxlen=self.DATA_POINTS_TO_DISPLAY)
# Create Plot Widget
self.scrolling_timestamp_plot_widget = pg.PlotWidget(axisItems={'bottom': TimeAxisItem(orientation='bottom')})
# Enable/disable plot squeeze (Fixed axis movement)
self.scrolling_timestamp_plot_widget.plotItem.setMouseEnabled(x=False, y=False)
self.scrolling_timestamp_plot_widget.setTitle('Scrolling Timestamp Plot Example')
self.scrolling_timestamp_plot_widget.setLabel('left', 'Value')
self.scrolling_timestamp_plot_widget.setLabel('bottom', 'Time (s)')
self.scrolling_timestamp_plot = self.scrolling_timestamp_plot_widget.plot()
self.scrolling_timestamp_plot.setPen(246,212,255)
self.layout = QtGui.QGridLayout()
self.layout.addWidget(self.scrolling_timestamp_plot_widget)
self.read_position_thread()
self.start()
def start(self):
"""Update plot"""
self.position_update_timer = QtCore.QTimer()
self.position_update_timer.timeout.connect(self.plot_updater)
self.position_update_timer.start(self.get_scrolling_timestamp_plot_refresh_rate())
def read_position_thread(self):
"""Read in data using a thread"""
self.current_position_value = 0
self.position_update_thread = Thread(target=self.read_position, args=())
self.position_update_thread.daemon = True
self.position_update_thread.start()
def read_position(self):
frequency = self.get_scrolling_timestamp_plot_frequency()
while True:
self.current_position_value = random.randint(1,101)
time.sleep(frequency)
def plot_updater(self):
self.data_point = float(self.current_position_value)
self.data.append({'x': self.timestamp.elapsed(), 'y': self.data_point})
self.scrolling_timestamp_plot.setData(x=[item['x'] for item in self.data], y=[item['y'] for item in self.data])
def clear_scrolling_timestamp_plot(self):
self.data.clear()
def get_scrolling_timestamp_plot_frequency(self):
return self.FREQUENCY
def get_scrolling_timestamp_plot_refresh_rate(self):
return self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE
def get_scrolling_timestamp_plot_layout(self):
return self.layout
def get_current_position_value(self):
return self.current_position_value
def get_scrolling_timestamp_plot_widget(self):
return self.scrolling_timestamp_plot_widget
# Start Qt event loop unless running in interactive mode or using pyside
if __name__ == '__main__':
# Create main application window
app = QtWidgets.QApplication([])
app.setStyle(QtGui.QStyleFactory.create("Cleanlooks"))
mw = QtGui.QMainWindow()
mw.setWindowTitle('Scrolling Plot Example')
# Create scrolling plot
scrolling_timestamp_plot_widget = ScrollingTimestampPlot()
# Create and set widget layout
# Main widget container
cw = QtGui.QWidget()
ml = QtGui.QGridLayout()
cw.setLayout(ml)
mw.setCentralWidget(cw)
# Can use either to add plot to main layout
#ml.addWidget(scrolling_timestamp_plot_widget.get_scrolling_timestamp_plot_widget(),0,0)
ml.addLayout(scrolling_timestamp_plot_widget.get_scrolling_timestamp_plot_layout(),0,0)
mw.show()
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
PyQt4
from PyQt4 import QtCore, QtGui
from threading import Thread
from collections import deque
import pyqtgraph as pg
import numpy as np
import random
import sys
import time
"""Scrolling Timestamp Plot Widget Example"""
class TimeAxisItem(pg.AxisItem):
"""Internal timestamp for x-axis"""
def __init__(self, *args, **kwargs):
super(TimeAxisItem, self).__init__(*args, **kwargs)
def tickStrings(self, values, scale, spacing):
"""Function overloading the weak default version to provide timestamp"""
return [QtCore.QTime().addMSecs(value).toString('mm:ss') for value in values]
class ScrollingTimestampPlot(QtGui.QWidget):
"""Scrolling plot widget with timestamp on x-axis and dynamic y-axis"""
def __init__(self, parent=None):
super(ScrollingTimestampPlot, self).__init__(parent)
# Internal timestamp for x-axis
self.timestamp = QtCore.QTime()
self.timestamp.start()
# Desired Frequency (Hz) = 1 / self.FREQUENCY
# USE FOR TIME.SLEEP (s)
self.FREQUENCY = 0.025
# Screen refresh rate to update plot (ms)
# self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE = 1 / Desired Frequency (Hz) * 1000
# USE FOR TIMER.TIMER (ms)
self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE = self.FREQUENCY * 1000
self.DATA_POINTS_TO_DISPLAY = 200
# Automatically pops from left if length is full
self.data = deque(maxlen=self.DATA_POINTS_TO_DISPLAY)
# Create Plot Widget
self.scrolling_timestamp_plot_widget = pg.PlotWidget(axisItems={'bottom': TimeAxisItem(orientation='bottom')})
# Enable/disable plot squeeze (Fixed axis movement)
self.scrolling_timestamp_plot_widget.plotItem.setMouseEnabled(x=False, y=False)
self.scrolling_timestamp_plot_widget.setTitle('Scrolling Timestamp Plot Example')
self.scrolling_timestamp_plot_widget.setLabel('left', 'Value')
self.scrolling_timestamp_plot_widget.setLabel('bottom', 'Time (s)')
self.scrolling_timestamp_plot = self.scrolling_timestamp_plot_widget.plot()
self.scrolling_timestamp_plot.setPen(246,212,255)
self.layout = QtGui.QGridLayout()
self.layout.addWidget(self.scrolling_timestamp_plot_widget)
self.read_position_thread()
self.start()
def start(self):
"""Update plot"""
self.position_update_timer = QtCore.QTimer()
self.position_update_timer.timeout.connect(self.plot_updater)
self.position_update_timer.start(self.get_scrolling_timestamp_plot_refresh_rate())
def read_position_thread(self):
"""Read in data using a thread"""
self.current_position_value = 0
self.position_update_thread = Thread(target=self.read_position, args=())
self.position_update_thread.daemon = True
self.position_update_thread.start()
def read_position(self):
frequency = self.get_scrolling_timestamp_plot_frequency()
while True:
self.current_position_value = random.randint(1,101)
time.sleep(frequency)
def plot_updater(self):
self.data_point = float(self.current_position_value)
self.data.append({'x': self.timestamp.elapsed(), 'y': self.data_point})
self.scrolling_timestamp_plot.setData(x=[item['x'] for item in self.data], y=[item['y'] for item in self.data])
def clear_scrolling_timestamp_plot(self):
self.data.clear()
def get_scrolling_timestamp_plot_frequency(self):
return self.FREQUENCY
def get_scrolling_timestamp_plot_refresh_rate(self):
return self.SCROLLING_TIMESTAMP_PLOT_REFRESH_RATE
def get_scrolling_timestamp_plot_layout(self):
return self.layout
def get_current_position_value(self):
return self.current_position_value
def get_scrolling_timestamp_plot_widget(self):
return self.scrolling_timestamp_plot_widget
# Start Qt event loop unless running in interactive mode or using pyside
if __name__ == '__main__':
# Create main application window
app = QtGui.QApplication([])
app.setStyle(QtGui.QStyleFactory.create("Cleanlooks"))
mw = QtGui.QMainWindow()
mw.setWindowTitle('Scrolling Plot Example')
# Create scrolling plot
scrolling_timestamp_plot_widget = ScrollingTimestampPlot()
# Create and set widget layout
# Main widget container
cw = QtGui.QWidget()
ml = QtGui.QGridLayout()
cw.setLayout(ml)
mw.setCentralWidget(cw)
# Can use either to add plot to main layout
#ml.addWidget(scrolling_timestamp_plot_widget.get_scrolling_timestamp_plot_widget(),0,0)
ml.addLayout(scrolling_timestamp_plot_widget.get_scrolling_timestamp_plot_layout(),0,0)
mw.show()
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
這篇關于如何使用pyqtgraph TimeAxisItem使X軸時間動態刷新的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！
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