Table 2. Comparison of the Experimental Results of Different Optimization Algorithms for the GRU Model.

model	running time/s	MSE of the training set	MSE of the test set
SGD	3	0.000899	0.000836
SGDM	3	0.000470	0.000435
NAG	4	0.000469	0.000433
RMSProp	3	0.000459	0.000421
AdaGrad	4	0.000478	0.000439
AdaDelta	4	0.000474	0.000436
Adam	4	0.000463	0.000432
Adamax	4	0.000458	0.000423