Example #1
0
    def _compute_cross_correlation(self, small_ts, input_ts_h5):
        """
        Cross-correlate two one-dimensional arrays. Return a CrossCorrelation datatype with result.
        """
        # (tpts, nodes, nodes, state-variables, modes)
        result_shape = self._result_shape(small_ts.data.shape)
        self.log.info("result shape will be: %s" % str(result_shape))

        result = numpy.zeros(result_shape)

        # TODO: For region level, 4s, 2000Hz, this takes ~3hours...(which makes node_coherence seem positively speedy
        # Probably best to add a keyword for offsets, so we just compute +- some "small" range...
        # One inter-node correlation, across offsets, for each state-var & mode.
        for mode in range(result_shape[4]):
            for var in range(result_shape[3]):
                data = input_ts_h5.data[:, var, :, mode]
                data = data - data.mean(axis=0)[numpy.newaxis, :]
                # TODO: Work out a way around the 4 level loop:
                for n1 in range(result_shape[1]):
                    for n2 in range(result_shape[2]):
                        result[:, n1, n2, var, mode] = correlate(data[:, n1], data[:, n2], mode="same")

        self.log.debug("result")
        self.log.debug(narray_describe(result))

        offset = (small_ts.sample_period *
                  numpy.arange(-numpy.floor(result_shape[0] / 2.0), numpy.ceil(result_shape[0] / 2.0)))

        cross_corr = CrossCorrelation(source=small_ts, array_data=result, time=offset)

        return cross_corr
Example #2
0
def find_delta_with_xcorr(signal1, signal2):
    if signal1.std() == 0 or signal2.std() == 0:
        return True, None, None
    signal1 -= signal1.mean()
    signal2 -= signal2.mean()
    signal1 /= signal1.std()
    signal2 /= signal2.std()
    nsamples = signal1.shape[0]

    xcorr = signaltools.correlate(signal1, signal2)
    # print(xcorr)
    dt = np.arange(1 - nsamples, nsamples)
    filtered_xcorr = xcorr[len(xcorr) // 2 - 20:len(xcorr) // 2 + 20]
    recovered_time_shift = dt[len(xcorr) // 2 - 20 + filtered_xcorr.argmax()]
    return False, xcorr, recovered_time_shift
Example #3
0
    def evaluate(self):
        """
        Cross-correlate two one-dimensional arrays.
        """
        cls_attr_name = self.__class__.__name__ + ".time_series"
        self.time_series.trait["data"].log_debug(owner=cls_attr_name)

        #(tpts, nodes, nodes, state-variables, modes)
        result_shape = self.result_shape(self.time_series.data.shape)
        LOG.info("result shape will be: %s" % str(result_shape))

        result = numpy.zeros(result_shape)

        #TODO: For region level, 4s, 2000Hz, this takes ~3hours...(which makes node_coherence seem positively speedy...)
        # Probably best to add a keyword for offsets, so we just compute +- some "small" range...
        # One inter-node correlation, across offsets, for each state-var & mode.
        for mode in range(result_shape[4]):
            for var in range(result_shape[3]):
                data = self.time_series.data[:, var, :, mode]
                data = data - data.mean(axis=0)[numpy.newaxis, :]
                #TODO: Work out a way around the 4 level loop:
                for n1 in range(result_shape[1]):
                    for n2 in range(result_shape[2]):
                        result[:, n1, n2, var, mode] = correlate(data[:, n1],
                                                                 data[:, n2],
                                                                 mode="same")

        util.log_debug_array(LOG, result, "result")

        offset = (self.time_series.sample_period *
                  numpy.arange(-numpy.floor(result_shape[0] / 2.0),
                               numpy.ceil(result_shape[0] / 2.0)))

        cross_corr = temporal_correlations.CrossCorrelation(
            source=self.time_series,
            array_data=result,
            time=offset,
            use_storage=False)

        return cross_corr
 def evaluate(self):
     """
     Cross-correlate two one-dimensional arrays.
     """
     cls_attr_name = self.__class__.__name__+".time_series"
     self.time_series.trait["data"].log_debug(owner = cls_attr_name)
     
     #(tpts, nodes, nodes, state-variables, modes)
     result_shape = self.result_shape(self.time_series.data.shape)
     LOG.info("result shape will be: %s" % str(result_shape))
     
     result = numpy.zeros(result_shape)
     
     #TODO: For region level, 4s, 2000Hz, this takes ~3hours... (which makes node_coherence seem positively speedy...)
     #TODO: Probably best to add a keyword for offsets, so we just compute +- some "small" range...
     #One inter-node correllation, across offsets, for each state-var & mode.
     for mode in range(result_shape[4]):
         for var in range(result_shape[3]):
             data = self.time_series.data[:, var, :, mode]
             data = data - data.mean(axis=0)[numpy.newaxis, :]
             #TODO: Work out a way around the 4 level loop,
             for n1 in range(result_shape[1]):
                 for n2 in range(result_shape[2]):
                     result[:, n1, n2, var, mode] = correlate(data[:, n1],
                                                              data[:, n2],
                                                              mode="same")
     
     util.log_debug_array(LOG, result, "result")
     
     offset = (self.time_series.sample_period *
               numpy.arange(-(numpy.floor(result_shape[0] / 2.0)),
                            numpy.ceil(result_shape[0] / 2.0)))
     
     cross_corr = temporal_correlations.CrossCorrelation(
         source = self.time_series,
         array_data = result,
         time = offset,
         use_storage = False)
     
     return cross_corr
Example #5
0
def center_signal(sig, shift=0.0):
    '''
    Given a signal on a periodic domain with a dominant 
    sine component, remove the phase shift from the signal 
    and return it.
    
    DEV: This function seems to cause the direction to randomly
    switch sides
    '''
    theta_vals = linspace(0, 2 * pi, len(sig))
    sig0 = sin(theta_vals)
    sig0 = heaviside(theta_vals - pi)
    mdpt = int(len(sig) / 2)

    max_ind = argmax(abs(correlate(sig, sig0)))
    max_ind = mod(max_ind, len(sig))

    out_sig = hstack((sig[max_ind:], sig[:max_ind]))

    # this is a pretty shaky way to get this phase shift
    if sum(out_sig[:mdpt]) > sum(out_sig[mdpt:]):
        out_sig = hstack((out_sig[mdpt:], out_sig[:mdpt]))

    return out_sig
Example #6
0
             for val in data[x][y]:
                 theta = mt.atan(val[1]/val[0]) if val[0] != 0 else (mt.pi/2 if val[1] > 0 else 1.5*mt.pi)
                 if lastTheta is not None and abs(theta - lastTheta) > 1:
                     theta = theta + mt.pi
                 lastTheta = theta
                 polarData[x][y].append([mt.sqrt(val[0]**2 + val[1]**2), theta])
     
     # print(polarData)
     plt.clf()
     wave1 = fft([theta[1] for theta in polarData[0][0]])
     wave2 = fft([theta[1] for theta in polarData[0][1]])
     wave1 = wave1[3:len(wave1)-2]
     wave2 = wave2[3:len(wave2)-2]
     plt.plot(wave1)
     plt.plot(wave2)
     xcor = np.argmax(correlate(wave1, wave2))
     theta = theta*(1-BETA) + xcor*BETA
     print(theta)
     # plt.polar(0, 500)
     # plt.polar(theta, np.mean([dat[0] for dat in polarData[0][0]]), marker='o')
     # plt.plot([theta[1] for theta in polarData[1][0]])
     # plt.plot([theta[1] for theta in polarData[1][1]])
     plt.draw()
     plt.pause(0.0001)
     # Reset
     data = [[[], []], [[], []]]
 elif line.find("#Receiving") != -1:
     # This is the beginning, let's set defaults
     ready = True
     data = [[[], []], [[], []]] # [Antenna0rx, Antenna1rx] each with [Antenna0tx, Antenna1tx]
     plt.ion()