How to replace variable names in a mat file

Hi, I want to change the naming conventions of a matfile variables. Ex: Original name: CAN_<XXX>_BUS To be changed to: W_YYY_<XXX>_BUS

I am looking for a m script that can read and replace the variables? I prepared a excel sheet with both the namings in a separate column, so that script will search for the existing name and find the name to be replaced. Can anybody help me to do this?

regards, Joseph

Answer 1

[Adam]

If you load the mat file into a struct (i.e. the load option with output argument), then your variables become fields of that struct which allows you to rename them (renaming variables themselves is not a fun task). You can then save the struct back out to the mat file with the '-struct' flag.

e.g.

varStruct = load( matFile );

...

save( matFile, '-struct', 'varStruct' );

As far as code goes to actually do the structure field renaming though I don't have time personally to do that, but someone else probably will and it should be simple string manipulation with functions such as strrep.

Bear in mind you can access a field name of a struct using a dynamic string as:

myFieldName = getFieldNameStringFromSomewhere();
myStruct.( myFieldName );

rather than having to hard-code the fieldname.

Answer 2

[CAM]

Adam's answer is the correct algorithm.

Additions:

Use the fieldnames command to get a cell array of field names from the structure. Use strrep to create new field names using the new convention. Finally, create a new structure using the new field names and save it.

% Air code, so please double-check all syntax
fn_old = fieldnames(varStruct);
fn_new = strrep(fn_old, oldStringPart, newStringPart); 
for z = 1:length(fn_old)
  varStruct_output.(fn_new{z}) = varStruct.(fn_old{z});  % Note the dot-parens notation
end

Hope that helps

[Joseph Stalin]

Thanks for the quick reply. Things start moving from my side.

Answer 3

[Khalid CHOUA]

Thank you so much @Adam & @CAM for your answers !