Reshaping nested struct array to cell array having elements with different sizes

Question

In MATLAB, I have a struct array of the following form:

a(1).b.c = rand(1,10);
a(1).b.cSize = length(a(1).b.c);
a(2).b.c = rand(1,11);
a(2).b.cSize = length(a(2).b.c);
a(3).b.c = rand(1,12);
a(3).b.cSize = length(a(3).b.c);
a(4).b.c = rand(1,13);
a(4).b.cSize = length(a(4).b.c);
a(5).b.c = rand(1,14);
a(5).b.cSize = length(a(5).b.c);
a(6).b.c = rand(1,15);
a(6).b.cSize = length(a(6).b.c);

I would like to create a cell array c that contains the differently sized fields a.b.c of the nested struct, without using for loops.

I tried the following:

c = {a.b.c}

which is not working and returns the following error message:

Expected one output from a curly brace or dot indexing expression, but there were 6 results.

The best solution I've found so far is the following

cellfun(@(x) x.c, {a.b}, 'UniformOutput', false)

Is there a faster solution without using cellfun? Maybe some reshape command?

rahnema1 rahnema1 · Accepted Answer · 2017-08-07T12:39:46

You can create a structrue array from a.b then extract the field c from the array.

ab = [a.b];
result = {ab.c}

Reshaping nested struct array to cell array having elements with different sizes

2 Answers