D-W= ∑(Et-Et-1)^2/∑Et^2,Et是第t期的残差,Et-1是第t-1期的残差,∑是对t从第2期到第t期求和,^2表示闭裤平方.
在D-W小于等于2时,D-W检验法则规定:
如D-W>d U,认为ei无自相关;
有自相关.
如4-D-W<dL,认为ei存在负自相关;
如dL<4-D-W<dU,不能确定是否<span style="color: rgb(51, 51, 51)font-family: "&amp">
有自相关.例如:数据x,y导入matlab可以求出残差,时间序列为【1:1:20】,再利用Excel就可以求出DW,结合上面的喊态手DW检验判断ei是否具有自相关性。如果没有就是普通的线性回归,如果有,重新建立新的模型。
x =
1.0e+02 *
1.273000000000000
1.300000000000000
1.327000000000000
1.294000000000000
1.350000000000000
1.371000000000000
1.412000000000000
1.428000000000000
1.455000000000000
1.453000000000000
1.483000000000000
1.466000000000000
1.502000000000000
1.531000000000000
1.573000000000000
1.607000000000000
1.642000000000000
1.656000000000000
1.687000000000000
1.717000000000000
>>y
y =
20.960000000000001
21.399999999999999
21.960000000000001
21.520000000000000
22.390000000000001
22.760000000000002
23.480000000000000
23.660000000000000
24.100000000000001
24.010000000000002
24.539999999999999
24.300000000000001
25.000000000000000
25.640000000000001
26.359999999999999
26.980000000000000
27.520000000000000
27.780000000000001
28.239999999999998
28.780000000000001
>>k=polyfit(x,y,1)
>>A=k(1)
>>B=k(2)
>>scatter(x,y,'-')
>>hold on
>>A
A =
0.176290106553353
>>B
B =
-1.457589881004317
>>y1=A*x+B
y1
20.984140683237555
21.460123970931608
21.936107258625661
21.354349906999598
22.341574503698375
22.711783727460418
23.434573164329166
23.716637334814532
24.192620622508585
24.157362601197917
24.686232920857975
24.386539739717271
25.021184123309343
25.532425432314071
26.272843879838156
26.872230242119553
27.489245615056291
27.736051764230986
28.282551094546381
28.811421414206439
>>x
x =
1.0e+02 *
1.273000000000000
1.300000000000000
1.327000000000000
1.294000000000000
1.350000000000000
1.371000000000000
1.412000000000000
1.428000000000000
1.455000000000000
1.453000000000000
1.483000000000000
1.466000000000000
1.502000000000000
1.531000000000000
1.573000000000000
1.607000000000000
1.642000000000000
1.656000000000000
1.687000000000000
1.717000000000000
>>y
y =
20.960000000000001
21.399999999999999
21.960000000000001
21.520000000000000
22.390000000000001
22.760000000000002
23.480000000000000
23.660000000000000
24.100000000000001
24.010000000000002
24.539999999999999
24.300000000000001
25.000000000000000
25.640000000000001
26.359999999999999
26.980000000000000
27.520000000000000
27.780000000000001
28.239999999999998
28.780000000000001
>>x=[ones(20,1),x]
x =
1.0e+02 *
0.010000000000000 1.273000000000000
0.010000000000000 1.300000000000000
0.010000000000000 1.327000000000000
0.010000000000000 1.294000000000000
0.010000000000000 1.350000000000000
0.010000000000000 1.371000000000000
0.010000000000000 1.412000000000000
0.010000000000000 1.428000000000000
0.010000000000000 1.455000000000000
0.010000000000000 1.453000000000000
0.010000000000000 1.483000000000000
0.010000000000000 1.466000000000000
0.010000000000000 1.502000000000000
0.010000000000000 1.531000000000000
0.010000000000000 1.573000000000000
0.010000000000000 1.607000000000000
0.010000000000000 1.642000000000000
0.010000000000000 1.656000000000000
0.010000000000000 1.687000000000000
0.010000000000000 1.717000000000000
>>[b,bint,r,rint,stats]=regress(y,x,0.05)
b =
-1.457589881004317
0.176290106553353
bint =
-1.915783961023543 -0.999395800985091
0.173199098501920 0.179381114604787
r =
-0.024140683237555
-0.060123970931610
0.023892741374340
0.165650093000401
0.048425496301626
0.048216272539584
0.045426835670835
-0.056637334814532
-0.092620622508583
-0.147362601197916
-0.146232920857976
-0.086539739717271
-0.021184123309343
0.107574567685930
0.087156120161843
0.107769757880448
0.030754384943709
0.043948235769015
-0.042551094546383
-0.031421414206438
rint =
-0.197380214591832 0.149098848116723
-0.234089240235379 0.113841298372159
-0.154875657364706 0.202661140113385
0.011358385565306 0.319941800435497
-0.130852274009141 0.227703266612392
-0.132455310112963 0.228887855192131
-0.137385784544954 0.228239455886624
-0.239133423038235 0.125858753409171
-0.271758881008546 0.086517635991379
-0.316600686646691 0.021875484250859
-0.315878102151843 0.023412260435891
-0.266571280710952 0.093491801276411
-0.206112831653057 0.163744585034371
-0.068631104926293 0.283780240298153
-0.090160666136194 0.264472906459881
-0.064278724936611 0.279818240697506
-0.146265745654130 0.207774515541547
-0.130937032188002 0.218833503726033
-0.213963196628595 0.128861007535830
-0.199398817443354 0.136555989030478
stats =
1.0e+04 *
Columns 1 through 2
0.000099874786001 1.435738949226265
Columns 3 through 4
0.000000000000000 0.000000767910880
一致性检验能不能通过和RI矩阵有关系的,你这个检验要求更严格一些所以通过不了。我这有推荐的RI矩阵,你可以用逗册我的这个函数试试,应该没问题。或者你自己更改一下RI矩阵。山枣宏不过不能改的太大,如果要求太松了,检验就没有意义了。
function A=myjudge()disp('输岩宏入要判定的矩阵')
A=input('A=')
disp('特征值为:')
[V,D]=eig(A)
D1=diag(D)
D1=D1.'
disp('对应的特征向量为:')
V
disp('最大特征值为:')
m=max(D(:))
[n,z]=size(A)
CI=(m-n)/(n-1)
RI=[0 0 0.58 0.90 1.12 1.24 1.32 1.41 1.45 1.49 1.51]
ri=RI(n)
CR=CI/ri
disp('是否通过一致性检验?')
if(CR>0.1)
disp('not pass')
else
disp('pass')
[r,c]=find(m==D)
v=V(:,c)
disp('权向量为')
B=v./sum(v)
end
end
怎样用matlab进行列联表检验1、相关系数就用命令corrcoef
min(min(corrcoef(x1, x2))) 就滚昌是x1,x2之间的相关系数。
比如
t = (1:0.1:100)'
w = 2*pi
x1=sin(w*t)+randn(size(t))
x2=cos(w*t)+randn(size(t))
x3=sin(w*t)+randn(size(t))
x1_x2 = min(min(corrcoef(x1, x2)))
x1_x3 = min(min(corrcoef(x1, x3)))
2、用corrcoef函拦备清数
设a1,b1,c1,d1 ,a2,b2,c2,d2 分别为f(x)和g(x)的系简前数
x=[a1,b1,c1,d1]
y=[a2,b2,c2,d2]
z=corrcoef(x,y)
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