Table/categorical arrays and the <undefined> category

4 次查看（过去 30 天）

显示更早的评论

Phillip 2014-6-3

2
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/132262-table-categorical-arrays-and-the-undefined-category

评论： dpb 2014-6-4

在 MATLAB Online 中打开

I create a table with different data. Some of the data I set as categorical arrays as such:

table.field = categorical(table.field);

This works fine. When there are NaNs or empty strings within table.field matlab automatically assigns '<undefined>' to those. Also not a problem. However, when I do a unique on them, each '<undefined>' is seen as unique instead of the same. The only way I see around this is to do something like:

table.field(isundefined(table.field)) = 'None';

That seems like a hack. Surely is must be possible to specify what the undefined "label" is in the syntax call?

Hope I'm missing something, Regards, Phil

3 个评论
显示 1更早的评论隐藏 1更早的评论

Phillip 2014-6-4

Thanks for pointing that out. I did miss that function. Although it seems that it does the opposite to what I want. It takes non-standard inputs and changes it into the standard missing variables which is undefined etc. Still wouldn't solve my uniqueness problem.

dpb 2014-6-4

I may have misinterpreted--my thought was perhaps one could use the function to force the missing value and that internally that might just cause the symptom to go away.

I still recommend this be submitted to "official" support for resolution of whether it is intended behavior or not--it seems wrong-headed if so on the face of it. Perhaps TMW has a reason we're not seeing, but I'd guess it's a fignewton of an implementation detail and isn't really thought out as of yet.

请先登录，再进行评论。

请先登录，再回答此问题。