transform.py 文件源码

def test_time(res, off, t, signal):
    """Time domain analytical half-space solution.
    - Source at x = y = z = 0 m
    - Receiver at y = z = 0 m; x = off
    - Resistivity of halfspace res
    - Times t, t > 0 s
    - Impulse response if signal = 0
    - Switch-on response if signal = 1
    """
    tau = np.sqrt(mu_0*off**2/(res*t))
    fact1 = res/(2*np.pi*off**3)
    fact2 = tau/np.sqrt(np.pi)
    if signal == 0:
        return fact1*tau**3/(4*t*np.sqrt(np.pi))*np.exp(-tau**2/4)
    else:
        resp = fact1*(2 - special.erf(tau/2) + fact2*np.exp(-tau**2/4))
        if signal < 0:
            DC = test_time(res, off, 1000000, 1)
            resp = DC-resp
        return resp


# Time-domain solution