Efficient way to change a struct of (mixed-type) arrays into a structure array?

Hi! Resulting from a DB query, I have a 6-field scalar struct consisting of 1522-element arrays, some cell, some numeric (if that matters); I want to convert it into a 1522x1 struct array with the same six fields--is there a non-for-loop way to do this?

[Jan]

Please provide example data in valid Matlab syntax. "6-field scalar struct consisting of 1522-element arrays, some cell, some numeric" does neither define the inputs nor the wanted output unequivocally. As you see in the given answers, forcing contributors to guess the details is no efficient method to get your problem solved.

Answer 1

[Walter Roberson]

I am not sure if there is a loop-less way to handle the situation if the field names are not known in advance. But perhaps the below is good enough, when "A" is your scalar struct:

B = [fieldnames(A).';cellfun(@num2cell,struct2cell(A).','un',0)]
C = struct(B{:}};

[David Goldsmith]

Same comment as below.

[Walter Roberson]

In my tests, the code works with cells as well. I have not tried with nested structures or objects, though.

Looking at the code for num2cell(), I can see that the code should work for any field which can be handle numel() and linear subscript referencing.

Answer 2

[Azzi Abdelmalek]

%  A contains multiple array (num, str,...)
 eval(sprintf('a.field%d=A(:,%d);',[1 :6;1:6]))

[Azzi Abdelmalek]

i have problems to format code

[David Goldsmith]

As I said in my post, the arrays in my scalar struct are of mixed type, i.e., some are numeric, some are cell (and not numeric-valued cell arrays). Thanks anyway.

[Azzi Abdelmalek]

it's just an example, the code is valid for your case

[Azzi Abdelmalek]

tell us what is the size of your cell array: size(A)

[Jan]

No, Azzi, do not use EVAL to access structs. "Dynamic fieldnames" are much more efficient and cleaner: a.(sprintf('field%d', i)). The topic EVAL has been discussed hundreds of times in this forum.