Limitations for table variable name

Question

Andrey Kazak 2015-10-22

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/250417-limitations-for-table-variable-name

评论： Steven Lord 2021-2-9

采纳的回答： Walter Roberson

在 MATLAB Online 中打开

Hello, dear community!

I try to name table variable with non-Latin character, for example Cyrillic:

>> a = table(zq, 'VariableNames', cellstr('я'));
Error using matlab.internal.tableUtils.makeValidName (line 36)
'я' is not a valid variable name.
Error in setVarNames (line 48)
[newnames,wasMadeValid] = matlab.internal.tableUtils.makeValidName(newnames,exceptionMode); % will warn if mods are made
Error in table (line 305)
            t = setVarNames(t,vnames); % error if invalid, duplicate, or empty

If I do the same, but with variable named using Latin characters, then everything works fine. What could cause this error? Is this normal behavior?

Thank you.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2015-10-22

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/250417-limitations-for-table-variable-name#answer_197010

Normal. The names have the same restrictions as matlab variable names. Latin letter to start, continue with digits or underscore or Latin letters

6 个评论
显示 4更早的评论隐藏 4更早的评论

Andrey Kazak 2015-10-28

Thank you, Walter. I made this in the following way:

Created a matrix with the data and added top row of NaN
xlswrite the matrix to a new XLSX file
Created cell array of text headers, which is basically a row of text cells
xlswrite the cell array to the same XLSX file

In the result I get with excel spreadsheet with header line and data.

In summary it seems not very convenient that MATLAB table column names are limited to MATLAB variable naming convention.

Walter Roberson 2015-10-28

If using xlswrite is acceptable, then use num2cell() to convert the numeric matrix to a cell array, add the headers to the top of that, and xlswrite() the whole thing out.

请先登录，再进行评论。

Answer 2

Vy Le 2021-2-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/250417-limitations-for-table-variable-name#answer_618607

Hi, why I write it and they said 'inifity norm of number c' is not a valid table variable name

Thank you.

names = {'inifity norm of condition number c','infinity norm of the residual r1'};

table(c,r1,'VariableNames',names)

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Steven Lord 2021-2-9

在 MATLAB Online 中打开

Prior to release R2019b table variable names were required to be valid MATLAB identifiers. In particular, that meant no spaces. That limitation was removed in release R2019b.

v = (1:5).';
A = table(v, v.^2, v.^3, 'VariableNames', ["v", "v squared", "v^3"])
A = 5x3 table
    v    v squared    v^3
    _    _________    ___

    1        1          1
    2        4          8
    3        9         27
    4       16         64
    5       25        125