Nickel Price Forecast Based on the LSTM Neural Network Optimized by the Improved PSO Algorithm

Table 7

The comparison of relative errors of the six models.

	PSO-LSTM11 (%)	PSO-LSTM12 (%)	PSO-LSTM21 (%)	PSO-LSTM22 (%)	LSTM (%)	ARIMA (%)
Maximum value	9.31	9.25	9.18	9.05	9.55	13.07
Minimum value	0.46	0.33	0.32	0.18	0.62	0.67