def getzpos_cm(self):
     return meter2cm(self.zpos)
 def getypos_cm(self):
     return meter2cm(self.ypos)
 def estDistance(kappa, eta,rxpwr, txpwr, d0=1.0):
     return meter2cm(d0*np.exp((txpwr-rxpwr+kappa)/(10.0*eta)))
 def getxpos_cm(self):
     return meter2cm(self.xpos)
 def estDistance(kappa, eta, diffpwr, d0=1):
     return meter2cm(d0*np.exp((diffpwr+kappa)/(10.0*eta)))