How to convert a structure int16 into a matrix?

I am opening a variable (VAR) which is a structure and it contains inside 3 field which column of numbers (a,b,c) and 4th column (c) with a structure 700x4. I would like to work with c(:, 3), but by using the code

struct2array(VAR.C(:,3));

I obtain the error: Undefined function 'struct2cell' for input arguments of type 'int16' How to solve it?

str2double

also does not work...

Answer 1

[Stephen23]

You don't need to do anything extra, because this is already the numeric data that you want:

VAR.C(:,3)

VAR is a structure, so you could apply struct2cell to this, but there is no point for what you are doing. The field of a structure can be any class: numeric, cell, struct, function handle, ... In your case the field C is numeric, with class int16, so you don't need to apply any other functions to make it numeric... it already is numeric!

str2double would only make sense to apply if you have a character vectors, a string array, or a cell array of char vectors. You don't appear to have any of those in your data.

You should revise the basic data types, and how to access structure data:

https://www.mathworks.com/help/matlab/matlab_prog/fundamental-matlab-classes.html

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-structure-array.html