Exemple #1
0
    def to_timeseries(self, delta_t=None):
        """ Return the Fourier transform of this time series.

        Note that this assumes even length time series!

        Parameters
        ----------
        delta_t : {None, float}, optional
            The time resolution of the returned series. By default the
        resolution is determined by length and delta_f of this frequency
        series.

        Returns
        -------
        TimeSeries:
            The inverse fourier transform of this frequency series.
        """
        from pycbc.fft import ifft
        from pycbc.types import TimeSeries, real_same_precision_as
        nat_delta_t =  1.0 / ((len(self)-1)*2) / self.delta_f
        if not delta_t:
            delta_t = nat_delta_t

        # add 0.5 to round integer
        tlen  = int(1.0 / self.delta_f / delta_t + 0.5)
        flen = int(tlen / 2 + 1)

        if flen < len(self):
            raise ValueError("The value of delta_t (%s) would be "
                             "undersampled. Maximum delta_t "
                             "is %s." % (delta_t, nat_delta_t))
        if not delta_t:
            tmp = self
        else:
            tmp = FrequencySeries(zeros(flen, dtype=self.dtype),
                             delta_f=self.delta_f, epoch=self.epoch)
            tmp[:len(self)] = self[:]

        f = TimeSeries(zeros(tlen,
                           dtype=real_same_precision_as(self)),
                           delta_t=delta_t)
        ifft(tmp, f)
        f._delta_t = delta_t
        return f
Exemple #2
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    def to_timeseries(self, delta_t=None):
        """ Return the Fourier transform of this time series.

        Note that this assumes even length time series!
        
        Parameters
        ----------
        delta_t : {None, float}, optional
            The time resolution of the returned series. By default the 
        resolution is determined by length and delta_f of this frequency 
        series.
        
        Returns
        -------        
        TimeSeries: 
            The inverse fourier transform of this frequency series. 
        """
        from pycbc.fft import ifft
        from pycbc.types import TimeSeries, real_same_precision_as
        nat_delta_t =  1.0 / ((len(self)-1)*2) / self.delta_f
        if not delta_t:
            delta_t = nat_delta_t

        # add 0.5 to round integer
        tlen  = int(1.0 / self.delta_f / delta_t + 0.5)
        flen = tlen / 2 + 1
        
        if flen < len(self):
            raise ValueError("The value of delta_t (%s) would be "
                             "undersampled. Maximum delta_t "
                             "is %s." % (delta_t, nat_delta_t))
        if not delta_t:
            tmp = self
        else:
            tmp = FrequencySeries(zeros(flen, dtype=self.dtype), 
                             delta_f=self.delta_f, epoch=self.epoch)
            tmp[:len(self)] = self[:]
        
        f = TimeSeries(zeros(tlen, 
                           dtype=real_same_precision_as(self)),
                           delta_t=delta_t)
        ifft(tmp, f)
        return f
Exemple #3
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    def to_frequencyseries(self, delta_f=None):
        """ Return the Fourier transform of this time series

        Parameters
        ----------
        delta_f : {None, float}, optional
            The frequency resolution of the returned frequency series. By
        default the resolution is determined by the duration of the timeseries.

        Returns
        -------
        FrequencySeries:
            The fourier transform of this time series.
        """
        from pycbc.fft import fft
        if not delta_f:
            delta_f = 1.0 / self.duration

        # add 0.5 to round integer
        tlen = int(1.0 / delta_f / self.delta_t + 0.5)
        flen = int(tlen / 2 + 1)

        if tlen < len(self):
            raise ValueError("The value of delta_f (%s) would be "
                             "undersampled. Maximum delta_f "
                             "is %s." % (delta_f, 1.0 / self.duration))
        if not delta_f:
            tmp = self
        else:
            tmp = TimeSeries(zeros(tlen, dtype=self.dtype),
                             delta_t=self.delta_t,
                             epoch=self.start_time)
            tmp[:len(self)] = self[:]

        f = FrequencySeries(zeros(flen, dtype=complex_same_precision_as(self)),
                            delta_f=delta_f)
        fft(tmp, f)
        f._delta_f = delta_f
        return f
Exemple #4
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    def to_frequencyseries(self, delta_f=None):
        """ Return the Fourier transform of this time series

        Parameters
        ----------
        delta_f : {None, float}, optional
            The frequency resolution of the returned frequency series. By
        default the resolution is determined by the duration of the timeseries.

        Returns
        -------
        FrequencySeries:
            The fourier transform of this time series.
        """
        from pycbc.fft import fft
        if not delta_f:
            delta_f = 1.0 / self.duration

        # add 0.5 to round integer
        tlen  = int(1.0 / delta_f / self.delta_t + 0.5)
        flen = int(tlen / 2 + 1)

        if tlen < len(self):
            raise ValueError("The value of delta_f (%s) would be "
                             "undersampled. Maximum delta_f "
                             "is %s." % (delta_f, 1.0 / self.duration))
        if not delta_f:
            tmp = self
        else:
            tmp = TimeSeries(zeros(tlen, dtype=self.dtype),
                             delta_t=self.delta_t, epoch=self.start_time)
            tmp[:len(self)] = self[:]

        f = FrequencySeries(zeros(flen,
                           dtype=complex_same_precision_as(self)),
                           delta_f=delta_f)
        fft(tmp, f)
        return f