How to run if and exist ?

Question

Luca 2021-5-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/825600-how-to-run-if-and-exist

评论： Luca 2021-5-15

Hi,

I'm trying to run this loop.

for year= 1962:2016
        for id=10000:93436          
                sub_regress = subsetPCA(subsetPCA.ID ==id & subsetPCA.years==year,:);
                if size(sub_regress,1) ~= 0
                        [~, IDPCA1, yearsPCA1]= findgroups(sub_regress.ID, sub_regress.years);
                        [~, IDPCAd, datesPCA1] = findgroups(sub_regress.ID, sub_regress.dates);
                        modeltest = fitlm(sub_regress, 'RET~PC1+PC2+PC3+PC4+PC5');
                        RES_PCA = modeltest.Residuals.Raw;
                        RES_PCAtbl= table(IDPCAd,datesPCA1, RES_PCA);
                        RES_PCAtbl.Properties.VariableNames([1 2])  = {'ID' 'dates'};
                        if exist final_residuals 
                                final_residuals =[final_residuals; RES_PCA];
                        else
                                final_residuals = RES_PCA;
                        end
                        
                end
        end
end

For some reason it is not acepting final_residual in the if exist function with if statement? Does someone know how what the problem is?

Thank you in advance

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Jonas 2021-5-9

try running it using bracket like

a=5;
exist('a','var')

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Answer 1

VBBV 2021-5-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/825600-how-to-run-if-and-exist#answer_695435

编辑：VBBV 2021-5-9

final_residuals = []
for year= 1962:2016
        for id=10000:93436          
                sub_regress = subsetPCA(subsetPCA.ID ==id & subsetPCA.years==year,:);
                if size(sub_regress,1) ~= 0
                        [~, IDPCA1, yearsPCA1]= findgroups(sub_regress.ID, sub_regress.years);
                        [~, IDPCAd, datesPCA1] = findgroups(sub_regress.ID, sub_regress.dates);
                        modeltest = fitlm(sub_regress, 'RET~PC1+PC2+PC3+PC4+PC5');
                        RES_PCA = modeltest.Residuals.Raw;
                        RES_PCAtbl= table(IDPCAd,datesPCA1, RES_PCA);
                        RES_PCAtbl.Properties.VariableNames([1 2])  = {'ID' 'dates'};
                        A = exist('final_residuals')
                        if A
                                final_residuals =[final_residuals; RES_PCA];
                        else
                                final_residuals = RES_PCA;
                        end
                        
                end
        end
end