plotLoss

plt.figure(figsize=(8,6))

epochs = range(1, 21)

plt.plot(epochs, val_loss_values1, 'b', linewidth=5, label='Validation loss, ReLU, 16 neurons')
plt.plot(epochs, val_loss_values2, 'r', linewidth=5, label='Validation loss, Sigmoid, 16 neurons')
plt.plot(epochs, val_loss_values3, 'c', linewidth=5, label='Validation loss, ReLU, 64 neurons')
plt.plot(epochs, val_loss_values4, 'k', linewidth=5, label='Validation loss, Sigmoid, 64 neurons')

plt.title('Training and validation loss',fontsize=22)
plt.xlabel('Epochs',fontsize=18)
plt.ylabel('Loss',fontsize=18)

plt.tick_params(axis='both', which='major', direction='inout', length=15, labelsize=20)

plt.legend(fontsize=16,frameon=False)