Effective Utilization of Data for Predicting COVID-19 Dynamics: An Exploration through Machine Learning Models

Table 9

RAE values of decision tree models for confirmed cases.

Forecast period (days)	Cumulative cases				Daily cases
	Germany	Japan	South Korea	Ukraine	Germany	Japan	South Korea	Ukraine
Train 3	0.013721	0.017121	0.012359	0.025513	0.249812	0.237307	0.22947	0.337549
Test 3	1.64074	3.008135	2.036247	2.242518	0.453807	1.99414	1.026396	1.397268
Train 7	0.024372	0.033182	0.023655	0.055279	0.252583	0.333357	0.250018	0.339791
Test 7	2.011061	2.101346	1.996374	1.767298	0.722817	0.856205	1.541001	1.202903
Train 14	0.047708	0.059617	0.044003	0.09951	0.326598	0.432997	0.432744	0.403959
Test 14	2.342152	2.110279	1.933691	1.848344	0.76622	1.046646	1.806664	1.176185
Train 21	0.070645	0.082996	0.063977	0.14188	0.3988	0.49228	0.614732	0.451253
Test 21	2.285203	2.112131	1.904707	1.813019	0.88611	1.043608	1.623965	1.232625
Train 30	0.106036	0.116719	0.093445	0.200639	0.408735	0.577086	0.789252	0.685385
Test 30	2.353681	2.07895	1.93567	1.908543	1.025704	1.073062	1.60721	1.124144