ra_fftsink.py

这是用python语言写的一个数字广播的信号处理工具包。利用它

        x = max(abs(self.ra_fftsink.sample_rate), abs(self.ra_fftsink.baseband_freq))
        if x >= 1e9:
            sf = 1e-9
            units = "GHz"
        elif x >= 1e6:
            sf = 1e-6
            units = "MHz"
        elif x >= 1e3:
            sf = 1e-3
            units = "kHz"
        else:
            sf = 1.0
            units = "Hz"

        if self.ra_fftsink.input_is_real:     # only plot 1/2 the points
            x_vals = ((numpy.arange (L/2)
                       * (self.ra_fftsink.sample_rate * sf / L))
                      + self.ra_fftsink.baseband_freq * sf)
            points = numpy.zeros((len(x_vals), 2), numpy.float64)
            points[:,0] = x_vals
            points[:,1] = dB[0:L/2]
        else:
            # the "negative freqs" are in the second half of the array
            x_vals = ((numpy.arange(-L/2, L/2)
                       * (self.ra_fftsink.sample_rate * sf / L))
                      + self.ra_fftsink.baseband_freq * sf)
            points = numpy.zeros((len(x_vals), 2), numpy.float64)
            points[:,0] = x_vals
            points[:,1] = numpy.concatenate ((dB[L/2:], dB[0:L/2]))

        lines = plot.PolyLine (points, colour='BLUE')
        graphics = plot.PlotGraphics ([lines],
                                      title=self.ra_fftsink.title,
                                      xLabel = units, yLabel = "dB")

        self.Draw (graphics, xAxis=None, yAxis=self.y_range)
        d = calc_max - calc_min
        d = d * 0.1
        if self.ra_fftsink.autoscale == True:
            self.y_range = self._axisInterval ('min', calc_min-d, calc_max+d)
        else:
            self.update_y_range ()

    def set_peak_hold(self, enable):
        self.peak_hold = enable
        self.peak_vals = None

    def update_y_range (self):
        ymax = self.ra_fftsink.ref_level
        ymin = self.ra_fftsink.ref_level - self.ra_fftsink.y_per_div * self.ra_fftsink.y_divs
        self.y_range = self._axisInterval ('min', ymin, ymax)

    def on_average(self, evt):
        # print "on_average"
        self.ra_fftsink.set_average(evt.IsChecked())

    def on_peak_hold(self, evt):
        # print "on_peak_hold"
        self.ra_fftsink.set_peak_hold(evt.IsChecked())

    def on_autoscale(self, evt):
        self.ra_fftsink.set_autoscale(evt.IsChecked())

    def on_incr_ref_level(self, evt):
        # print "on_incr_ref_level"
        self.ra_fftsink.set_ref_level(self.ra_fftsink.ref_level
                                   + self.ra_fftsink.y_per_div)

    def on_decr_ref_level(self, evt):
        # print "on_decr_ref_level"
        self.ra_fftsink.set_ref_level(self.ra_fftsink.ref_level
                                   - self.ra_fftsink.y_per_div)

    def on_incr_y_per_div(self, evt):
        # print "on_incr_y_per_div"
        self.ra_fftsink.set_y_per_div(next_up(self.ra_fftsink.y_per_div, (0.5,1,2,5,10)))

    def on_decr_y_per_div(self, evt):
        # print "on_decr_y_per_div"
        self.ra_fftsink.set_y_per_div(next_down(self.ra_fftsink.y_per_div, (0.5,1,2,5,10)))

    def on_y_per_div(self, evt):
        # print "on_y_per_div"
        Id = evt.GetId()
        if Id == self.id_y_per_div_1:
            self.ra_fftsink.set_y_per_div(0.5)
        elif Id == self.id_y_per_div_2:
            self.ra_fftsink.set_y_per_div(1.0)
        elif Id == self.id_y_per_div_5:
            self.ra_fftsink.set_y_per_div(2.0)
        elif Id == self.id_y_per_div_10:
            self.ra_fftsink.set_y_per_div(5.0)
        elif Id == self.id_y_per_div_20:
            self.ra_fftsink.set_y_per_div(10)

        
    def on_right_click(self, event):
        menu = self.popup_menu
        for id, pred in self.checkmarks.items():
            item = menu.FindItemById(id)
            item.Check(pred())
        self.PopupMenu(menu, event.GetPosition())

    def on_motion(self, event):
        if not self.ra_fftsink.xydfunc == None:
            xy = self.GetXY(event)
            self.ra_fftsink.xydfunc (xy)

    def build_popup_menu(self):
        self.id_incr_ref_level = wx.NewId()
        self.id_decr_ref_level = wx.NewId()
        self.id_autoscale = wx.NewId()
        self.id_incr_y_per_div = wx.NewId()
        self.id_decr_y_per_div = wx.NewId()
        self.id_y_per_div_1 = wx.NewId()
        self.id_y_per_div_2 = wx.NewId()
        self.id_y_per_div_5 = wx.NewId()
        self.id_y_per_div_10 = wx.NewId()
        self.id_y_per_div_20 = wx.NewId()
        self.id_average = wx.NewId()
        self.id_peak_hold = wx.NewId()

        self.Bind(wx.EVT_MENU, self.on_average, id=self.id_average)
        self.Bind(wx.EVT_MENU, self.on_peak_hold, id=self.id_peak_hold)
        self.Bind(wx.EVT_MENU, self.on_autoscale, id=self.id_autoscale)
        self.Bind(wx.EVT_MENU, self.on_incr_ref_level, id=self.id_incr_ref_level)
        self.Bind(wx.EVT_MENU, self.on_decr_ref_level, id=self.id_decr_ref_level)
        self.Bind(wx.EVT_MENU, self.on_incr_y_per_div, id=self.id_incr_y_per_div)
        self.Bind(wx.EVT_MENU, self.on_decr_y_per_div, id=self.id_decr_y_per_div)
        self.Bind(wx.EVT_MENU, self.on_y_per_div, id=self.id_y_per_div_1)
        self.Bind(wx.EVT_MENU, self.on_y_per_div, id=self.id_y_per_div_2)
        self.Bind(wx.EVT_MENU, self.on_y_per_div, id=self.id_y_per_div_5)
        self.Bind(wx.EVT_MENU, self.on_y_per_div, id=self.id_y_per_div_10)
        self.Bind(wx.EVT_MENU, self.on_y_per_div, id=self.id_y_per_div_20)


        # make a menu
        menu = wx.Menu()
        self.popup_menu = menu
        menu.AppendCheckItem(self.id_average, "Average")
        menu.AppendCheckItem(self.id_peak_hold, "Peak Hold")
        menu.Append(self.id_incr_ref_level, "Incr Ref Level")
        menu.Append(self.id_decr_ref_level, "Decr Ref Level")
        # menu.Append(self.id_incr_y_per_div, "Incr dB/div")
        # menu.Append(self.id_decr_y_per_div, "Decr dB/div")
        menu.AppendSeparator()
        # we'd use RadioItems for these, but they're not supported on Mac
        menu.AppendCheckItem(self.id_autoscale, "Autoscale")
        menu.AppendCheckItem(self.id_y_per_div_1, "0.5 dB/div")
        menu.AppendCheckItem(self.id_y_per_div_2, "1.0 dB/div")
        menu.AppendCheckItem(self.id_y_per_div_5, "2.0 dB/div")
        menu.AppendCheckItem(self.id_y_per_div_10, "5.0 dB/div")
        menu.AppendCheckItem(self.id_y_per_div_20, "10.0 dB/div")

        self.checkmarks = {
            self.id_average : lambda : self.ra_fftsink.average,
            self.id_peak_hold : lambda : self.ra_fftsink.peak_hold,
            self.id_autoscale : lambda : self.ra_fftsink.autoscale,
            self.id_y_per_div_1 : lambda : self.ra_fftsink.y_per_div == 0.5,
            self.id_y_per_div_2 : lambda : self.ra_fftsink.y_per_div == 1.0,
            self.id_y_per_div_5 : lambda : self.ra_fftsink.y_per_div == 2.0,
            self.id_y_per_div_10 : lambda : self.ra_fftsink.y_per_div == 5.0,
            self.id_y_per_div_20 : lambda : self.ra_fftsink.y_per_div == 10.0,
            }


def next_up(v, seq):
    """
    Return the first item in seq that is > v.
    """
    for s in seq:
        if s > v:
            return s
    return v

def next_down(v, seq):
    """
    Return the last item in seq that is < v.
    """
    rseq = list(seq[:])
    rseq.reverse()

    for s in rseq:
        if s < v:
            return s
    return v


# ----------------------------------------------------------------
#          	      Deprecated interfaces
# ----------------------------------------------------------------

# returns (block, win).
#   block requires a single input stream of float
#   win is a subclass of wxWindow

def make_ra_fft_sink_f(fg, parent, title, fft_size, input_rate, ymin = 0, ymax=50):
    
    block = ra_fft_sink_f(fg, parent, title=title, fft_size=fft_size, sample_rate=input_rate,
                       y_per_div=(ymax - ymin)/8, ref_level=ymax)
    return (block, block.win)

# returns (block, win).
#   block requires a single input stream of gr_complex
#   win is a subclass of wxWindow

def make_ra_fft_sink_c(fg, parent, title, fft_size, input_rate, ymin=0, ymax=50):
    block = ra_fft_sink_c(fg, parent, title=title, fft_size=fft_size, sample_rate=input_rate,
                       y_per_div=(ymax - ymin)/8, ref_level=ymax)
    return (block, block.win)


# ----------------------------------------------------------------
# Standalone test app
# ----------------------------------------------------------------

class test_app_flow_graph (stdgui.gui_flow_graph):
    def __init__(self, frame, panel, vbox, argv):
        stdgui.gui_flow_graph.__init__ (self, frame, panel, vbox, argv)

        fft_size = 256

        # build our flow graph
        input_rate = 20.000e3

        # Generate a complex sinusoid
        src1 = gr.sig_source_c (input_rate, gr.GR_SIN_WAVE, 5.75e3, 1000)
        #src1 = gr.sig_source_c (input_rate, gr.GR_CONST_WAVE, 5.75e3, 1000)

        # We add these throttle blocks so that this demo doesn't
        # suck down all the CPU available.  Normally you wouldn't use these.
        thr1 = gr.throttle(gr.sizeof_gr_complex, input_rate)

        sink1 = ra_fft_sink_c (self, panel, title="Complex Data", fft_size=fft_size,
                            sample_rate=input_rate, baseband_freq=100e3,
                            ref_level=60, y_per_div=10)
        vbox.Add (sink1.win, 1, wx.EXPAND)
        self.connect (src1, thr1, sink1)

        src2 = gr.sig_source_f (input_rate, gr.GR_SIN_WAVE, 5.75e3, 1000)
        #src2 = gr.sig_source_f (input_rate, gr.GR_CONST_WAVE, 5.75e3, 1000)
        thr2 = gr.throttle(gr.sizeof_float, input_rate)
        sink2 = ra_fft_sink_f (self, panel, title="Real Data", fft_size=fft_size*2,
                            sample_rate=input_rate, baseband_freq=100e3,
                            ref_level=60, y_per_div=10)
        vbox.Add (sink2.win, 1, wx.EXPAND)
        self.connect (src2, thr2, sink2)

def main ():
    app = stdgui.stdapp (test_app_flow_graph,
                         "FFT Sink Test App")
    app.MainLoop ()

if __name__ == '__main__':
    main ()