Remove structs from an array of structs

I have a 1x1 struct A with 13 fields. One of these field, B, is a 15x1 cell, each cell is a 1x1 struct with 5 fields. How can I remove some of these structures contained in the cell with particular value in the field called 'name'? I've tried in this way:

for k = 1 : length(A.B) if A.B{k,1}.name = 'relax' A.B{k,1} = [] end end

The error is:

Error: File: xxx.m Line: 5 Column: 45 The expression to the left of the equals sign is not a valid target for an assignment.

Answer 1

[Guillaume]

= is for assignment, == is for comparison. However, == does not work with strings, you use strcmp for that:

for cellidx = 1 : numel(A.B)  %numel is a lot safer than length
   if strcmp(A.B{cellidx}.name, 'relax')
      A.B{cellidx} = [];
   end
end

[Bartolomeo Ruotolo]

Thank you very much, Sir. Now to remove the empty rows, can I use reshape?

[Guillaume]

reshape will never remove any element. If you wanted to get rid of the cells of B instead of filling them with empty, this is what you should have done:

for cellidx = 1 : numel(A.B)  %numel is a lot safer than length
 if strcmp(A.B{cellidx}.name, 'relax')
    A.B(cellidx) = [];  %note the use of () instead of {}
 end
end

{} refers to the content of a cell, therefore when you do B{x} = []; you put empty in cell x.

() referes to the cell itself, therefore when you do B(x) = []; you remove the cell x itself.

If you've already set the cells content to empty, to delete those cells you'd do:

A.B(cellfun(@isempty, A.B)) = [];