gtsrb-find-learning-rate.py

def plot_loss_change(sched, sma=1, n_skip=20, y_lim=(-0.01,0.01)):
    """
    Plots rate of change of the loss function.
    Parameters:
        sched - learning rate scheduler, an instance of LR_Finder class.
        sma - number of batches for simple moving average to smooth out the curve.
        n_skip - number of batches to skip on the left.
        y_lim - limits for the y axis.
    """
    derivatives = [0] * (sma + 1)
    for i in range(1 + sma, len(sched.lrs)):
        derivative = (sched.losses[i] - sched.losses[i - sma]) / sma
        derivatives.append(derivative)
        
    plt.ylabel("d/loss")
    plt.xlabel("learning rate (log scale)")
    plt.plot(sched.lrs[n_skip:], derivatives[n_skip:])
    plt.xscale('log')
    plt.ylim(y_lim)
    
learn.lr_find()
plot_loss_change(learn.sched, sma=20, n_skip=20, y_lim=(-0.02, 0.01))