BP神经网络 预测 matlab代码

clear all;      %清除所有变量
close all;      %清图
clc;            %清屏
%%%%%原始数据%%%%
%前25天的imf1的值
 x1= [-4.6042	-1.7683	0.4888	2.214	3.4542	4.2564	4.6676	4.7348	4.5049	4.0249	3.3418	2.5026	1.5541	0.5435	-0.4875	-1.5173	-2.5256	-3.4767	-4.3251	-4.9869	-5.3089	-5.1219	-4.2571	-2.6267
];
x2=[-0.4686	1.8536	3.8464	5.2071	5.8714	5.8586	5.3301	4.468	3.3891	2.1883	0.9351	-0.3273	-1.5608	-2.7299	-3.8092	-4.7758	-5.6066	-6.2789	-6.7703	-7.0465	-7.0176	-6.5855	-5.6558	-4.154
];
x3=[-2.0836	0.4597	3.0897	5.3584	6.8413	7.2403	6.7433	5.6608	4.2902	2.8951	1.7297	0.7473	-0.162	-1.0345	-1.8684	-2.6572	-3.3943	-4.0811	-4.7315	-5.2812	-5.621	-5.6253	-5.1495	-4.1077
];
x4=[-2.6651	-1.0471	0.5305	1.8543	2.7468	3.226	3.4695	3.3029	2.3305	0.4301	-1.4918	-2.4136	-2.2199	-1.3834	-0.3989	0.528	1.2276	1.4985	1.