Remove rows from table with a column match and an undefined categorical

Question

Marcus Glover 2024-2-24

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2086218-remove-rows-from-table-with-a-column-match-and-an-undefined-categorical

评论： Voss 2024-2-24

I want to remove all rows from my table T that have a (or multiple) duplicate entries in T.Name and have a value that is undefined in the categorical variable T.Result.

T.Value should be preserved regardless.

%create result array with undefined categoricals
result = [string(missing);"PASS";string(missing);string(missing);"FAIL";"PASS"];
result = categorical(result);
%crreate original table
T=table(["Bill";"Steve";"Joe";"Steve";"Bob";"Steve"],[1;2;3;2;5;2],result,'VariableNames',["Name","Value","Result"]);
T.Result=char(T.Result) 
T = 6×3 table
     Name      Value      Result   
    _______    _____    ___________

    "Bill"       1      <undefined>
    "Steve"      2      PASS       
    "Joe"        3      <undefined>
    "Steve"      2      <undefined>
    "Bob"        5      FAIL       
    "Steve"      2      PASS       
%The solution would eliminate row 4 beacuse "Steve" has a match and T.Result is undefined
%Rows 1 and 3 stay because T.Name does not have a match. 
%Row 6 stays because T.Result is defined
solution=T([1:3 5:6],:)
solution = 5×3 table
     Name      Value      Result   
    _______    _____    ___________

    "Bill"       1      <undefined>
    "Steve"      2      PASS       
    "Joe"        3      <undefined>
    "Bob"        5      FAIL       
    "Steve"      2      PASS       

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Answer 1

Voss 2024-2-24

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2086218-remove-rows-from-table-with-a-column-match-and-an-undefined-categorical#answer_1415538

在 MATLAB Online 中打开

%create result array with undefined categoricals
result = [string(missing);"PASS";string(missing);string(missing);"FAIL";"PASS"];
result = categorical(result);
%crreate original table
T=table(["Bill";"Steve";"Joe";"Steve";"Bob";"Steve"],[1;2;3;2;5;2],result,'VariableNames',["Name","Value","Result"]);
T.Result=char(T.Result)
T = 6×3 table
     Name      Value      Result   
    _______    _____    ___________

    "Bill"       1      <undefined>
    "Steve"      2      PASS       
    "Joe"        3      <undefined>
    "Steve"      2      <undefined>
    "Bob"        5      FAIL       
    "Steve"      2      PASS       
% logical index by row of whether Name appears more than once in the table:
name_repeated = sum(T.Name.' == T.Name, 2) > 1;
% logical index by row of whether Result is '<undefined>':
result_missing = strcmp(strtrim(cellstr(T.Result)),'<undefined>');
% if you were to keep T.Result as categorical, you could use this expression instead:
% result_missing = ismissing(T.Result);
% rows to remove:
remove_row = name_repeated & result_missing;
% remove the rows:
T(remove_row,:) = []
T = 5×3 table
     Name      Value      Result   
    _______    _____    ___________

    "Bill"       1      <undefined>
    "Steve"      2      PASS       
    "Joe"        3      <undefined>
    "Bob"        5      FAIL       
    "Steve"      2      PASS       