Refer to structure names

Hi,

Suppose I have a structure A with a, b, c, d tables inside. My aim is to use names of tables within structure A (a, b, c, d) to create new tables in structure B. I tied to do this in the following way, however it does not work. Any ideas how to corect it?

B.(fieldnames(A)'){1} = table1
B.(fieldnames(A)'){2} = table2
....

Answer 1

[Stephen23]

F = fieldnames(A);
B.(F{1}) = table1
B.(F{2}) = table2

https://www.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html

[Joanna Przeworska]

Yes, I used this idea before and it worked, however, was wondering how to omit the first line, and link this part of code with the subsequent lines. Is it possible?

[Stephen23]

"Is it possible?"

Yes, but I would not recommend it:

A = struct('abc',123,'xyz',456)

A = struct with fields:
    abc: 123
    xyz: 456

X = 2; % 2nd fieldname
B.(subsref(fieldnames(A),substruct('{}',{X}))) = 789

B = struct with fields:
    xyz: 789

[Joanna Przeworska]

Could you explain why it is not recommended?

[Walter Roberson]

... because it is hard to read?

[Stephen23]

"Could you explain why it is not recommended?"

Because it is more complex. More complex code is more difficult to understand, more difficult to maintain, obfuscates the code intent, is more liable to bugs, and is more difficult to debug. It is also likely to be less efficient, as it requires multiple calls to fieldnames.

[Joanna Przeworska]

I see your point. Thank you for your help and clarifications.

Best regards, JP

Answer 2

[Matt J]

args = [fieldnames(A).'; {table1, table2, table3,...}]
    
B=struct(args{:})

[Joanna Przeworska]

Dear Matt,

Thank you for your response, whowever this is not exactly what I wanted to receive.

Answer 3

[Image Analyst]

"Suppose I have a structure A with a, b, c, d tables inside. My aim is to use names of tables within structure A (a, b, c, d) to create new tables in structure B."

So, why does this not work?

B = A;

New structure B will have all the same fields (a, b, c, and d) as existing structure A with the same names. Each field in the structure will have the same table as in A, which is what it seemed like you were trying to do when you assigned the tables. This also means that all the columns names of the tables of structure B will match the column names from the tables of structure A.

[Joanna Przeworska]

In my exercise, my goal is to dynamically refer to the field names of structure A in order to store the calculation in a different structure B, but with a name taken from structure A.

I don't know if I made it clear what I mean.