How I use fprintf to acess a struct?

I have defined the struct written down.

SATS_Hour = struct('SATS_H0',[],'SATS_H1',[],'SATS_H2',[],'SATS_H3',[],...
                   'SATS_H4',[],'SATS_H5',[],'SATS_H6',[],'SATS_H7',[],...
                 'SATS_H8',[],'SATS_H9',[],'SATS_H10',[],'SATS_H11',[],...
               'SATS_H12',[],'SATS_H13',[],'SATS_H14',[],'SATS_H15',[],...
               'SATS_H16',[],'SATS_H17',[],'SATS_H18',[],'SATS_H19',[],...
               'SATS_H20',[],'SATS_H21',[],'SATS_H22',[],'SATS_H23',[]);

I have to access a struct to write on each individual SATS_Hour.SATS_H0 for the first time of my loop, it contains 48 loops. The number after the letter H, of each variable, must change up to the last one 47.

How can I do this?

Using fprintf or other Matlab command?

Thanks for the help.

Gilberto Fernandes

Answer 1

[Guillaume]

Numbering variables or structure fields is a bad idea. Any time you start naming things sequentially you need to think of using an array instead. Here, for example you'd be better off using a cell array. I.e use:

SATS_Hour = cell(23, 1);  %instead of a structure
for idx = 1:23
   SATS_Hour{idx} = ...
end

Indexing is always easier than awkward name construction via sprintf. If you're hell bent on using a structure:

for idx = 1:23
   SATS_Hour.(sprintf('SATS_H%d', idx)) = ...
end

As you see, it's more complicated, less readable, and probably slower.

[Gilberto Santos]

The size of each fields in cell´s case may be different?

[Guillaume]

Behing the scenes, cell arrays and structures are identical. The only difference is that you access each element of a cell by indexing whereas for a structure it's by its name.

Each element of a cell array can be different size and type. Same as for a structure.

[Stephen23]

"If you're hell bent on using a structure" use a non-scalar structure:

for k = 1:23
    SATS_Hour(k).SATS_H = ...
end

[Guillaume]

I don't see how a structure array with just one field is any better than a cell array. Seems to add a level of indirection for no reason.

Answer 2

[Gilberto Santos]

Thanks a lot. I am running the main program when it finishes I will run the function with your code suggestion.

I will keep you informed ASAP.

Best Regards,

Gilberto Fernandes

Answer 3

[Gilberto Santos]

Thanks you All. It worked. I have accepted the advice of using a cell array.

Best Regards to All,

Gilberto Fernandes