Error when introducing dummy variables in a regression

Question

Maria 2014-8-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/152547-error-when-introducing-dummy-variables-in-a-regression

评论： Maria 2014-8-27

I am running the following regressions in Matlab:

tbl1=table(Y1,X1); 
mdl1=fitlm(tbl1,'Y1~X1'); 
mdl12=fitglm(tbl1,'Y1~X1','Distribution','binomial','link','probit'); 
mdl13=fitglm(tbl1,'Y1~X1','Distribution','binomial');

Y1 is my dependent variable, it’s binary, it only takes the values 0 or 1.
X1, the independent variable, is a 1-column logical variable. It is a dummy, it only takes the values of 1 and 0 too.

These 3 different models are working.

I alos built groups of dummies to control for different effects (e.g: year, industry, number of employees, etc) for example:

group1=cell2mat(A(:,5));
[~, ~, ugroup1] = unique(group1)
D1=dummyvar(ugroup1);
D1(:,1)=[0];                       %Define reference group
D1=logical(D1);

Or

group2=cell2mat(A(:,6));
x2 = [0 10 20 25 30 35 40 45 50 55 60 70 100 300];
[n2, idx2] = histc(group2, x2);
D2 = bsxfun(@eq, idx2, 1:length(x2)-1);
D2(:,1)=[0];

In total I have 94 dummies, grouped in 4 different logical arrays (D1-48 levels, D2-13 levels, D3- 6 levels and D4-27 levels).

What I am trying to do now is to add them to the regressions above:

tbl1=table(Y1,X1,D1,D2,D3,D4); 
mdl1=fitlm(tbl1,'Y1~X1+D1+D2+D3+D4'); 
mdl12=fitglm(tbl1,'Y1~X1+D1+D2+D3+D4','Distribution','binomial','link','probit'); 
mdl13=fitglm(tbl1,'Y1~X1+D1+D2+D3+D4','Distribution','binomial');

But I always get errors :

1.Error using classreg.regr.FitObject/selectVariables (line 402)
Predictor variables must be numeric vectors, numeric matrices, or categorical vectors.
2.Error in classreg.regr.TermsRegression/selectVariables (line 370)
            model = selectVariables@classreg.regr.ParametricRegression(model);
3.Error in classreg.regr.FitObject/doFit (line 217)
            model = selectVariables(model);