Matlab structure of struct

Hi!

I'd like to create structures and store them, but I don't know how to do it. For example, for a function, we write something like

function f=MyFunction(arg1,...,argN)

...

end

and then we write the different operations. This allows us to write MyValue=MyFunction(...). I'd like to do the same for structures, something like MyObject=MyStruct(...). Could someone give me a reference document which explains how to do this for structures please? So far, the only thing I found is how to create structures from the command window. Thanks!

[Jan]

Stucts can be defined in the code exactly as they are created in the command window. See:

doc struct
doc cell2struct
doc table2struct

[Florian Spicher]

I saw this doc. I might be wrong, but to create a structure like this we have to assign values to the fields right? Like stuct.field=sth. What I'd like is only have "a skeleton" of my struct, ie. only store its fields without any values assigned to them.

Answer 1

[Jan]

MyStruct = cell2struct(cell(2, 1), {'field1'; 'field2'})

MyStruct = struct with fields:
    field1: []
    field2: []

Now the fields exist, but contain empty matrices only.

[Florian Spicher]

Perfect! Thank you!

Answer 2

[Image Analyst]

Not sure what you mean. You can call the function whatever you want and it can take in and return whatever you want. If you want to create a custom structure, there is already a function called struct() to do that.

[Florian Spicher]

Oh ok! So I could write something like MyStuct=stuct('field1', 'field2',...) and just save it in a .m file? It would just be a one line file then?

[Image Analyst]

I believe so. Call repmat() if you want to create an array of those structs.

[Florian Spicher]

Could you elaborate a bit on that, please? It's probably basic but I started to use Matlab like a few weeks ago and I literally discoverd structures an hour ago. Things aren't straight forward for me yet.

[Image Analyst]

Looks like Jan showed you how to create one struct. If you want an array of them, call repmat():

MyStruct = cell2struct(cell(2, 1), {'field1'; 'field2'})
structArray = repmat(MyStruct, 5, 2	)

structArray will be a 5 by 2 array of structures.

If that helps, can you "Vote" for my answer?

[Florian Spicher]

Nice, it is definitely going to be useful to know that. Thanks a lot!

I already voted for your answer though!