Exemplo n.º 1
0
def logistic_logg(v, theta):
    (logH, logmH, dlogH, dlogmH) = logistic_logh(np.asarray(range(1, v
            + 1)), theta)

    logg = np.zeros((v, ))
    dlogg = np.zeros_like(dlogH)

    for ii in range(v):
        if ii == 0:
            logg[ii] = logH[ii]
            dlogg[ii, :] = dlogH[ii, :]
        else:
            logg[ii] = logmH[:ii].sum() + logH[ii]
            dlogg[ii, :] = dlogmH[:ii, :].sum(axis=0) + dlogH[ii, :]

    # exp(logmG) = 1 - G = 1 - cumsum(g) = 1 - cumsum(exp(logg)), but this is a much
    # more numerically stable way to do it that won't underflow for G close to 1.

    logmG = np.cumsum(logmH)
    dlogmG = np.cumsum(dlogmH, axis=0)

    return (logg, logmG, dlogg, dlogmG)
Exemplo n.º 2
0
    def evaluate(self,v):
        hazard = logistic_logh(self.hazard_params)
        (logH, logmH, dlogH, dlogmH) = hazard.evaluate(asarray(range(1,v+1)))

        logg  = zeros((v, ))
        dlogg = zeros_like(dlogH)

        for ii in range(v):
            if ii == 0:
                logg[ii]    = logH[ii]
                dlogg[ii,:] = dlogH[ii,:]
            else:
                logg[ii]    = logmH[:ii].sum() + logH[ii]
                dlogg[ii,:] = dlogmH[:ii,:].sum(axis=0) + dlogH[ii,:]

        # exp(logmG) = 1 - G = 1 - cumsum(g) = 1 - cumsum(exp(logg)), but this is a much
        # more numerically stable way to do it that won't underflow for G close to 1.

        logmG  = cumsum(logmH)
        dlogmG = cumsum(dlogmH, axis=0)

        return (logg, logmG, dlogg, dlogmG)
Exemplo n.º 3
0
def logistic_logg(v, theta):
    (logH, logmH, dlogH, dlogmH) = logistic_logh(np.asarray(range(1, v + 1)),
                                                 theta)

    logg = np.zeros((v, ))
    dlogg = np.zeros_like(dlogH)

    for ii in range(v):
        if ii == 0:
            logg[ii] = logH[ii]
            dlogg[ii, :] = dlogH[ii, :]
        else:
            logg[ii] = logmH[:ii].sum() + logH[ii]
            dlogg[ii, :] = dlogmH[:ii, :].sum(axis=0) + dlogH[ii, :]

    # exp(logmG) = 1 - G = 1 - cumsum(g) = 1 - cumsum(exp(logg)), but this is a much
    # more numerically stable way to do it that won't underflow for G close to 1.

    logmG = np.cumsum(logmH)
    dlogmG = np.cumsum(dlogmH, axis=0)

    return (logg, logmG, dlogg, dlogmG)