1、96 144 194 276 383 466 554 652 747 832 972111 169 235 400 459 565 695 805 881 1011 1139151 238 335 425 541 641 739 866 975 1087 1238164 263 376 531 600 711 913 1038 1173 1296 1497182 318 445 576 708 856 1000 1145 1292 1435 1667216 361 504 642 818 979 1142 1305 1479 1644 1920241 404 584 741 923 1114
2、1298 1492 1684 1885 2218试根据这些历史数据建立预测评估模型，评估2003年SARS疫情给该市商品零售业、旅游业和综合服务业所造成的影响。 月份1234预测值相对误差8379.878.185.191.98110.095696.94840.139285.85820.022193.08160.0162102.24430.1089106.46790.066195.92180.0281102.21450.012113.65270.0824116.9220.0698107.16510.0053112.24350.0324126.33410.0931128.40260.0085119
3、.72620.0226123.25650.01140.43040.0213141.01060.0422133.75960.0057135.35010.0146567886.688.290.386.794.00140.006495.34070.008999.46710.021298.64190.0086104.90410.0136105.48860.0027109.62530.0011108.95520.0022117.07140.0045116.71660.0109120.8210.0072120.34680.0139130.650.0372129.13980.0127133.160.0399
4、132.92950.0058145.80350.021142.88520.0091146.75910.027146.82770.0032910111293.392.590.996.999.17750.0482100.27170.0198103.71770.0269119.6310.0313110.9968112.63040.0129113.57470.0668126.0587124.22470.0335126.51240.0101124.36840.0211132.83170.0897139.02890.0163142.10530.0231136.1880.0508139.96860.0469
5、155.59750.0251159.62020.0153149.13080.0285147.48910.054SARS疫情对商品的零售额的影响情况如表1：月份 实际值163.2159.7158.4145.2124144.1156.0996154.8565149.4379148.6303162.7145158.09360.0435070.0303290.0565790.0236250.3122140.09711157162.6171.8180.7173.5176.5161.7471162.179174.1406179.2938163.3038155.41350.0302360.0025890.0
6、136240.0077820.0587680.11947表1. 2003年商品的零售额的实际值域预测值SARS疫情对接待海外旅游人数的影响情况如表月份15.417.123.511.61.782.6114.482839.44425.053831.992133.950432.39630.0595581.3066670.0661191.7579418.0732611.412388.816.220.124.926.521.829.115835.419133.751333.291230.730925.06452.3086141.1863640.6791690.3369960.1596570.149748
7、表2. 2003年接待海外旅游人数的实际值域预测值SARS疫情对综合服务业累计数额影响情况如表241404584741923111412981492168418852218279.5609434.9344608.102732.6269938.3021120.41299.31474.81685.51855.32189.40.1600040.076570.0412710.01130.0165790.0057450.0010020.0115280.0008910.0157560.012894程序如下：clc,clearx0=90.3 97.4 109.5 121.7 138.7 142.9;n=le
8、ngth（x0）;exp（-2/（n+1） exp（2/（n+1）;%级比范围x0=x0+800;lamda=x0（1:n-1）./x0（2:n）%落入级比范围range=minmax（lamda）x1=cumsum（x0）;%做一次累加for i=2:nz（i）=0.5*（x1（i）+x1（i-1）;%均值生成endB=-z（2:n）,ones（n-1,1）;Y=x0（2:;u=BYx=dsolve（Dx+a*x=b,x（0）=x0）;x=subs（x,abx0,u（1）,u（2）,x1（1）;yuce1=subs（x,t,0:n-1）;digits（6）,y=vpa（x） %为提高预测精度
9、，先计算预测值，再显示微分方程的解yuce=x0（1）,diff（yuce1）epsilon=x0-yuce %计算残差delta=abs（epsilon./x0） %计算相对误差rho=1-（1-0.5*u（1）/（1+0.5*u（1）*lamda %计算级比偏差值yuce=yuce-800%还原数值y1=156.0996 154.8565 149.4379 148.6303 162.7145 158.0936 161.7471 162.179 174.1406 179.2938 163.3038 155.4135;y2=163.2 159.7 158.4 145.2 124.0 144.1 157.0 162.6 171.8 180.7 173.5 176.5;x=1:12;plot（x,y2,-*,x,y1,-ro）legend（出现SARS疫情后商品的零售额正常情况下商品的零售额
