def write_constant(self, out_sac_path='./'):
""" Write constant component to SAC file.
:param out_sac_path: Output path, defaults to './'
:type out_sac_path: str, optional
"""
sac = SACTrace(data=self.harmonic_trans[0, :])
sac.b = self.tmin
sac.delta = self.rfsta.sampling
sac.user0 = 0.0
sac.user1 = self.rfsta.f0[0]
sac.stla = self.rfsta.stla
sac.stlo = self.rfsta.stlo
sac.stel = self.rfsta.stel
sac.write(
join(out_sac_path, '{}_constant_R.sac'.format(self.rfsta.staname)))
