li_ma_snr#

jinwu.lightcurve.li_ma_snr(n_on: float, n_off: float, alpha: float, *, signed: bool = True) → float[source]#

Compute Li & Ma significance (Eq. 17 in Li & Ma 1983).

Parameters:

  • n_on (float) – Total counts in ON region.

  • n_off (float) – Total counts in OFF region (reference background).

  • alpha (float) – Exposure/area scaling: alpha = (A_on/A_off) * (t_on/t_off).

  • signed (bool) – If True (default), return a signed significance — positive for source excess, negative for background deficit. Pass signed=False to get the unsigned magnitude (deviation from background hypothesis regardless of direction).

Returns:

Li & Ma significance. Returns 0.0 for degenerate inputs.

Return type:

float