regress函数进行回归分析,主要进行线性回归,一元和多元分析。
使用步骤:
1.输入x和y的数据x和y均为行向量,回归分析时需要使用x'和y'转化为列向量。
x1=[66.165,71.25,70.135,65.125,69.99,65.765,67.29,67.71,66.525,67.13,69.505,56.775,66.01,67.97,62.9,66.1,64.51,68.385,66.205,65.77,67.065,63.605,64.305,60.485,70.29,69.345,68.415,66.495,65.765,63.28,62.84]'
x2=[12857,24495,24250,10060,29931,18243,10763,9907,13255,9088,33772,8744,11494,20461,5382,19070,10935,22007,13594,11474,14335,7898,17717,15205,70622,47319,40643,11781,10658,11578,9725]'
Y=[71.54,73.92,73.27,71.20,73.91,72.54,70.66,71.85,71.08,71.29,74.70,65.49,68.95,73.34,65.96,72.37,70.07,72.55,71.65,71.73,73.10,67.47,69.87,67.41,78.14,76.10,74.91,72.91,70.17,66.03,64.37]'
2.转换x
x=[ones(size(x1)),x1,x2]
3.使用regress函数进行回归分析
[b,bint,r,rint,stats]=regress(Y,x)
注!!:b:回归系数 bint:回归系数的区间估计 r:残差
rint:置信空间 stats:检验回归模型的统计量:依次为判定系数、F统计量观测值、检验的p值、误差方差的估计。
4.绘制残差分析图(残差:观测值与预测值之间的差)
rcoplot(r,rint)