grads = K.gradients(loss, model.input)[0]
grads /= K.maximum(K.mean(K.abs(grads)), 1e-7)
outputs = [loss, grads]
fetch_loss_and_grads = K.function([model.input], outputs)

def eval_loss_and_grads(x):
    outs = fetch_loss_and_grads([x])
    loss_value = outs[0]
    grad_values = outs[1]
    return loss_value, grad_values
