Add field to input struct array in Mex

Dear All,

I would like to add and populate a new field in an existing struct array.

(Context: I just want to distribute the columns of a matrix into the struct array as vectors, but am seeing performance issues with the usual num2cell -> deal approach)

I had thought to try this in a Mex file, but didn't find any documentation/examples for .c, rather just warnings about input structure/cell arrays being read-only.

Is there a way to do this in a C-based Mex file? Or in a C++-based one? I would prefer to generate the field inside the Mex function, but I guess adding a placeholder for the field in an intermediate m-file function would also be fine.

Regards, MT

[James Tursa]

Please post a small example showing all inputs and desired output. I should warn you, however, that there is no official way to do this efficiently in a mex routine. To do it efficiently in a mex routine requires unofficial hacking into the mxArray structure to create reference copies. Doable, but probably not what you wanted.

Answer 1

[Swaraj]

In order to add a new field to the struct Array in Mex, you can use “mxAddField” function.

Please go through the following documentation for further details.

Add field to structure array - MATLAB (mathworks.com)