MATLAB: I have data workspace 1x617struc 1 field, every row has 1×1 struc with 4 fields, How to extract the 4th field of data for 617? thanks

{YourStruct.NameOf4thField}

A cell array is needed because the 4th field is not guaranteed to be consistent size or data type.

In the case where the 4th field is a numeric row vector of consistent size, then

   vertcat(YourStruct.NameOf4thField)

would give you a 617 x something numeric array

A = [Getval.pval];

struct fieldnames must be valid MATLAB identifiers, so spaces and brackets are not permitted.

The characters are permitted in the names of Variables in table() objects.

To add a new field at a particular location, the easiest way is to add the new field and then to use orderfields() to change the order.