Returns an array of the sample times in seconds for each point in the
        FID.

        :return: an array of the sample times in seconds for each point in the FID.

def time_axis(self):
        """
        Returns an array of the sample times in seconds for each point in the
        FID.

        :return: an array of the sample times in seconds for each point in the FID.
        """
        return numpy.arange(0.0, self.dt * self.np, self.dt)