dynamic plotting inside wx

[nbancajas]

hello everyone, i need some help regarding my python code.

it is a medical plotter/display program with wxagg backend. it reads 3 kinds of data from a text file: ecg, heart rate, and oxygen saturation. ecg data is plotted by embedding matplotlib inside wx, while the other two is wxStaticText. to differentiate them, a buffer character was introduced before each reading and parsed accordingly.

my PROBLEM is i want to make the program work without using wxYield. i've read somewhere that as much as possible it should be avoided. im thinking maybe use threading but i cant make it work like it should be. if i comment out the wxYield line the plot is updated, but the other two readings won't.

here is my code and the input textfile(truncated version of 'data.txt').

it requires wxpython,pyserial, and matplotlib modules.

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# generated by wxGlade 0.4.1 on Thu Aug 16 11:20:21 2007
 
from matplotlib.numerix import arange
import matplotlib
 
# uncomment the following to use wx rather than wxagg
#matplotlib.use('WX')
#from matplotlib.backends.backend_wx import FigureCanvasWx as FigureCanvas
 
# comment out the following to use wx rather than wxagg
matplotlib.use('WXAgg')
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
from matplotlib.backends.backend_wxagg import NavigationToolbar2WxAgg,Toolbar
 
from matplotlib.figure import Figure
 
import wx
import serial
 
class MyFrame(wx.Frame):    
 
    count = 1000     # this is the number of samples to display at a time
    t = arange(0.0,count,1)
    data = [0.3 for i in range(count)]  # storage for ECG graph data
    #ser = serial.Serial(port = '/dev/ttyUSB0', baudrate = 57600)  # for COM 1: port = 0, etc
    #ser = serial.Serial(port = 'COM2', baudrate = 57600)  # for COM 1: port = 0, etc
    txtfile = open('data.txt','r')  
 
    def __init__(self, *args, **kwds):
        # begin wxGlade: MyFrame.__init__
        kwds["style"] = wx.DEFAULT_FRAME_STYLE
        wx.Frame.__init__(self, *args, **kwds)
        self.sizer_8_staticbox = wx.StaticBox(self, -1, "")
        self.sizer_7_staticbox = wx.StaticBox(self, -1, "")
 
        self.spo2_display = wx.StaticText(self, -1, "0")
        self.spo2_statictxt = wx.StaticText(self, -1, "% Sp02")
        self.spo2_header = wx.StaticText(self, -1, "blood-oxygen saturation")
        self.bpm_display = wx.StaticText(self, -1, "0")
        self.bpm_statictxt = wx.StaticText(self, -1, "bpm")    
        self.bpm_header = wx.StaticText(self, -1, "heart rate")
 
        # Menu Bar
        # File menu
        self.Main_Menu = wx.MenuBar()
        self.SetMenuBar(self.Main_Menu)
        self.File = wx.Menu()
        self.Start_Display = wx.MenuItem(self.File, wx.NewId(), "Start Display", "", wx.ITEM_NORMAL)
        self.File.AppendItem(self.Start_Display)
        self.Exit = wx.MenuItem(self.File, wx.NewId(), "Exit", "", wx.ITEM_NORMAL)
        self.File.AppendItem(self.Exit)
        self.Main_Menu.Append(self.File, "File")
        # Edit menu
        self.Edit = wx.Menu()
        self.Options = wx.MenuItem(self.Edit,wx.NewId(),"Options","",wx.ITEM_NORMAL)
        self.Edit.AppendItem(self.Options)
        self.Main_Menu.Append(self.Edit,"Edit")
        # Help menu
        self.Help = wx.Menu()
        self.About = wx.MenuItem(self.Help,wx.NewId(),"About","",wx.ITEM_NORMAL)
        self.Help.AppendItem(self.About)
        self.Main_Menu.Append(self.Help,"Help")
        # Menu Bar end
 
        # Status bar
        self.Telemed_statusbar = self.CreateStatusBar(1, 0)
 
        # embed matplotlib
        self.figure = Figure()
        self.axes = self.figure.add_subplot(111)    # 111 means 1 row, 1 column on subplot #1
 
        #self.line, = self.axes.plot(self.t, self.data, 'r', linewidth = 3.0,color='#FF523A')
        self.line, = self.axes.plot(self.t, self.data, 'r', linewidth = 3.0,color='#FF351A')
 
 
        self.canvas = FigureCanvas(self, -1, self.figure)
        self.axes.set_title('ECG Waveform')
        #self.axes.set_ylim(0,3.3)
        self.axes.set_ylim(0.4,2.2)
        #self.axes.set_ylim(0,2.5)
        self.axes.grid(True)
        #self.sizer_1.Add(self.canvas, 0, wx.LEFT | wx.TOP | wx.GROW)
 
        # Toolbar for matplotlib canvas
        #self.toolbar = NavigationToolbar2WxAgg(self.canvas)
        self.toolbar = Toolbar(self.canvas)
        self.toolbar.Realize()
        if wx.Platform == '__WXMAC__':
            # Mac platform (OSX 10.3, MacPython) does not seem to cope with
            # having a toolbar in a sizer. This work-around gets the buttons
            # back, but at the expense of having the toolbar at the top
            self.SetToolBar(self.toolbar)
        else:
            # On Windows platform, default window size is incorrect, so set
            # toolbar width to figure width.
            tw, th = self.toolbar.GetSizeTuple()
            fw, fh = self.canvas.GetSizeTuple()
            # By adding toolbar in sizer, we are able to put it at the bottom
            # of the frame - so appearance is closer to GTK version.
            # As noted above, doesn't work for Mac.
            #self.toolbar.SetSize(wx.Size(fw, th))
            self.toolbar.SetSize(wx.Size(1000, th))
 
 
        self.toolbar.update()
 
        self.__set_properties()
        self.__do_layout()
        self.__bind_events()
        # end wxGlade
 
    def __set_properties(self):
        # begin wxGlade: MyFrame.__set_properties
        self.SetTitle("Telemed")
        self.SetSize((1280, 700))
 
        self.canvas.SetMinSize((1000, 501))
        self.canvas.SetPosition((40,40))
 
        self.spo2_header.SetFont(wx.Font(12, wx.DEFAULT, wx.NORMAL, wx.NORMAL, 0, "Sans"))
        self.spo2_header.SetForegroundColour(wx.Colour(35, 142, 35))
        self.spo2_display.SetMinSize((130, 78))
        self.spo2_display.SetBackgroundColour(wx.Colour(255, 255, 255))
        self.spo2_display.SetFont(wx.Font(45, wx.MODERN, wx.NORMAL, wx.BOLD, 0, "Sans"))
        self.spo2_display.SetForegroundColour(wx.Colour(35, 142, 35))
        self.spo2_statictxt.SetMinSize((103, 60))
        self.spo2_statictxt.SetFont(wx.Font(20, wx.MODERN, wx.ITALIC, wx.NORMAL, 0, "Sans"))
        self.spo2_statictxt.SetForegroundColour(wx.Colour(35, 142, 35))
 
        self.bpm_header.SetFont(wx.Font(12, wx.DEFAULT, wx.NORMAL, wx.NORMAL, 0, "Sans"))
        self.bpm_header.SetForegroundColour(wx.Colour(50, 50, 204))
        self.bpm_display.SetMinSize((130, 78))
        self.bpm_display.SetFont(wx.Font(45, wx.MODERN, wx.NORMAL, wx.BOLD, 0, "Sans"))
        self.bpm_display.SetForegroundColour(wx.Colour(50, 50, 204))
        self.bpm_statictxt.SetMinSize((60, 60))
        self.bpm_statictxt.SetFont(wx.Font(20, wx.MODERN, wx.ITALIC, wx.NORMAL, 0, "Sans"))       
        self.bpm_statictxt.SetForegroundColour(wx.Colour(50, 50, 204))
        #self.bpm_statictxt.SetBackgroundColour(wx.Colour(50, 50, 204))
 
 
 
        #self.canvas.SetBackgroundColour(wx.Colour(239, 235, 231))
 
        self.Telemed_statusbar.SetStatusWidths([-1])
        # statusbar fields
        Telemed_statusbar_fields = ["Ready"]
        for i in range(len(Telemed_statusbar_fields)):
            self.Telemed_statusbar.SetStatusText(Telemed_statusbar_fields[i], i)
        # end wxGlade
 
    def __do_layout(self):
        # begin wxGlade: MyFrame.__do_layout
        sizer_1 = wx.BoxSizer(wx.VERTICAL)
        sizer_2 = wx.BoxSizer(wx.HORIZONTAL)
        sizer_6 = wx.BoxSizer(wx.VERTICAL)
        sizer_8 = wx.StaticBoxSizer(self.sizer_8_staticbox, wx.HORIZONTAL)
        sizer_7 = wx.StaticBoxSizer(self.sizer_7_staticbox, wx.HORIZONTAL)
        #sizer_2.Add(self.panel_7, 1, wx.EXPAND, 0)
        #sizer_2.Add(self.toolbar, 0, wx.LEFT | wx.EXPAND)
        sizer_2.Add(self.canvas, 0, wx.LEFT | wx.TOP | wx.GROW | wx.EXPAND)
 
        sizer_6.Add(self.spo2_header, 0, wx.ALIGN_CENTER_HORIZONTAL|wx.ADJUST_MINSIZE, 0)
        sizer_7.Add(self.spo2_display, 0, wx.ALIGN_CENTER_VERTICAL|wx.ADJUST_MINSIZE, 1)
        sizer_7.Add(self.spo2_statictxt, 0, wx.ALIGN_CENTER_VERTICAL|wx.ADJUST_MINSIZE, 2)
        sizer_6.Add(sizer_7, 1, wx.EXPAND, 0)
 
        sizer_6.Add(self.bpm_header, 0, wx.ALIGN_CENTER_HORIZONTAL|wx.ADJUST_MINSIZE, 0)
        sizer_8.Add(self.bpm_display, 0, wx.ALIGN_CENTER_VERTICAL|wx.ADJUST_MINSIZE, 1)
        sizer_8.Add(self.bpm_statictxt, 0, wx.ALIGN_CENTER_VERTICAL|wx.ADJUST_MINSIZE, 2)
        sizer_6.Add(sizer_8, 1, wx.EXPAND, 0)
        sizer_6.Add((20, 80), 0, wx.ADJUST_MINSIZE, 0)
        sizer_6.Add((20, 80), 0, wx.ADJUST_MINSIZE, 0)
        sizer_6.Add((20, 80), 0, wx.ADJUST_MINSIZE, 0)
        sizer_2.Add(sizer_6, 1, wx.EXPAND, 0)
        sizer_1.Add(sizer_2, 1, wx.EXPAND, 0)
        self.SetAutoLayout(True)
        self.SetSizer(sizer_1)
        self.Layout()
        # end wxGlade
 
    def __bind_events(self):
        self.Bind(wx.EVT_MENU, self.startPlot, self.Start_Display)
        self.Bind(wx.EVT_MENU, self.onExit, self.Exit)
        #self.Bind(wx.EVT_MENU, self.onAbout, self.About)
 
    def onExit(self, event): # wxGlade: MyFrame.<event_handler>
        #self.ser.close()
        self.txtfile.close()
        self.Close()
 
    def startPlot(self, event): # wxGlade: MyFrame.<event_handler>
 
        #self.ser.flushInput()
        print 'ok here'
        buf = 30    #number of samples to take before redrawing ecg graph
 
        while 1:
            #input = self.ser.readline().strip('\r\n')
            input = self.txtfile.readline().strip('\r\n')
            #self.txtfile.write(input + '\n')
            #print input
            # check if input is from pulse ox or from ECG
            if input[0] == '-':
                if input.count('.') != 0:
                    continue
                if input.count('-') != 1:
                    continue
                if input.count('+') != 0:
                    continue
                self.spo2_display.SetLabel(input.strip('-'))
                #wx.Yield()
            elif input[0] == '+':
                if input.count('.') != 0:
                    continue
                if input.count('-') != 0:
                    continue
                if input.count('+') != 1:
                    continue
                self.bpm_display.SetLabel(input.strip('+'))
                #wx.Yield()
            elif input[0] == '.':
                if input.count('.') != 2:
                    continue
                if input.count('-') != 0:
                    continue
                if input.count('+') != 0:
                    continue
                del self.data[0]
                self.data.append(input.strip('.'))
                buf-= 1
                if buf <= 0:
                    buf = 30
                    self.line.set_data(self.t, self.data)
                    self.canvas.draw()
                    #wx.Yield()
 
    def OnPaint(self, event):
        self.canvas.draw()
 
# end of class MyFrame
 
 
class MyApp(wx.PySimpleApp):
    """Application class."""
    def OnInit(self):
        wx.InitAllImageHandlers()
        self.frame=MyFrame(None,-1,"")
        self.frame.Show()
        self.SetTopWindow(self.frame)
        return True
 
def main():
    app = MyApp()
    app.MainLoop()
 
if __name__ == "__main__":
    main()
 

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