Logistic_Regressor.py 文件源码

def gradient(x0, X, y, alpha):
    # gradient of the logistic loss

    w, c = x0[1:137], x0[0]

    #print("c is " + str(c))
    z = X.dot(w) + c
    z = phi(y * z)
    z0 = (z - 1) * y
    grad_w = np.matmul(z0,X) / X.shape[0] + alpha * w
    grad_c = z0.sum() / X.shape[0]

    grad_c = np.array(grad_c)
    #print(grad_w[0,1:5])
    return np.c_[([grad_c], grad_w)]


##### Stochastic Gradient Descent Optimiser ######