How do you get rid of the VariableNamingRule warning when you do want it set to modify ?

Hi, I have the following code:

opts = detectImportOptions(fullfile(file_B_path, file_B_name)); % Detects import of table
opts = setvartype(opts, 'ID', 'string'); % Sets ID to string datatype
opts = setvartype(opts, 'RvCCompliance', 'string'); % Sets RvC Compliance to string datatype
---> opts.VariableNamingRule = 'modify'; 
file_B = readtable(fullfile(file_B_path, file_B_name),opts); % Imports table

and I keep getting the following warning:

Warning: Column headers from the file were modified to make them valid MATLAB identifiers before 
creating variable names for the table. The original column headers are saved in the VariableDescriptions property.
Set 'VariableNamingRule' to 'preserve' to use the original column headers as table variable names.

I know that variablenamingrule is set to modify, in fact, I want it to be set to modify. Why wont adding the line with the pointer get rid of this messege ?

Answer 1

[dpb]

It's annoying to be constantly nagged, agreed. But, setting it explicitly doesn't affect whether it is generated or not as you've discovered.

But, while a pain to have to do every time use readtable, it's relatively simple to fix...

opts = detectImportOptions(fullfile(file_B_path, file_B_name)); % Detects import of table
opts = setvartype(opts, 'ID', 'string');                        % Sets ID to string datatype
opts = setvartype(opts, 'RvCCompliance', 'string');             % Sets RvC Compliance to string datatype
w=warning('off','MATLAB:table:ModifiedAndSavedVarnames');       % turn off annoying warning, save state
file_B = readtable(fullfile(file_B_path, file_B_name),opts);    % Imports table
warning(w);                                                     % reset warning level

Since 'modify' is the default state for the name preservation property, it doesn't need to be set in the options struct and makes no difference if it is (as you've seen).

[dpb]

"But, while a pain to have to do every time use readtable, ..."

One COULD turn it off and leave it off, of course, instead of resetting it. I've not yet gone to that point.

[Santiago Chazaro]

Thank you so much!

[Peter Perkins]

Santiago, this warning is a known issue that is left over from the days before VariableNamingRule. For now, the work-around is what dpb suggests.