How do I add a value to a field in each element of a struct array?

88 views (last 30 days)
Brandon Kuczenski
Brandon Kuczenski on 29 Apr 2014
Commented: Image Analyst on 29 Apr 2014
Say I have a struct array with a numeric field:
>> a=struct('bar',{47 52})
I want to increment that field across each element of the array, something like the following:
>> [] = [] + 1; % this fails
The nearest I can figure out is the following, which is cumbersome:
>> inc = num2cell([]+1);
>> [] = inc{:};
Is there a way to do this without creating an intermediate variable? Thanks in advance.

Answers (1)

Image Analyst
Image Analyst on 29 Apr 2014
Well why are you messing around with cell arrays? Why make it way more complicated than it needs to be??? I don't see any reason for a cell array. I think you need to read the FAQ:
Try using just regular numerical arrays:
% Create structure.
a=struct('bar',[47 52]) % Report to command window.
% Add 1 = % Report to command window.
In the command window:
a =
bar: [47 52]
ans =
47 52
a =
bar: [48 53]
ans =
48 53
Image Analyst
Image Analyst on 29 Apr 2014
Sorry, I misunderstood. A fast, straightforward and intuitive solution is to simply use a for loop:
for k = 1:length(a)
a(k).bar = a(k).bar+1;
Don't believe the hype about a for loop being slow. It's not. Assuming you have less than several million structures in the array, it should be very fast.

Sign in to comment.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!