Error when introducing dummy variables in a regression

7 ビュー (過去 30 日間)
Maria 2014 年 8 月 27 日
コメント済み: Maria 2014 年 8 月 27 日
I am running the following regressions in Matlab:
tbl1=table(Y1,X1);
mdl1=fitlm(tbl1,'Y1~X1');
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)=; %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)=;
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');
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);
I have been trying different options like changing the type of variable or adding for example
tbl1.D1=nominal(D1;
but it always gives error. I guess it must be related to the way I 'introduce' the dummy groups.
2 件のコメント表示非表示 1 件の古いコメント
Maria 2014 年 8 月 27 日
EDU>> whos D1 Name Size Bytes Class Attributes
D1 31982x48 12281088 double

サインインしてコメントする。

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!