CodexBloom - Programming Q&A Platform

Getting 'Index exceeds matrix dimensions' scenarios when trying to access elements in a nested struct array in MATLAB

👀 Views: 23 đŸ’Ŧ Answers: 1 📅 Created: 2025-06-14
matlab structs error-handling MATLAB

I'm migrating some code and I keep running into I'm working with an 'Index exceeds matrix dimensions' behavior when trying to access elements in a nested struct array in MATLAB. I have a struct array called `data` that looks like this: ```matlab data(1).values = [1, 2, 3]; data(1).meta = 'First'; data(2).values = [4, 5]; data(2).meta = 'Second'; ``` I want to loop through the `data` struct and access the `values` array of each struct to perform some calculations. However, when I attempt to access the `values` for the second element, I run into this scenario: ```matlab for i = 1:length(data) currentValues = data(i).values; % Perform some calculations result(i) = sum(currentValues); end ``` This code throws the behavior: ``` Index exceeds matrix dimensions. ``` I have verified that `data` contains two elements, and I believe the scenario arises when trying to access `currentValues` in the loop. I tried adding checks to ensure the `values` array exists before accessing it, like so: ```matlab for i = 1:length(data) if isfield(data(i), 'values') && ~isempty(data(i).values) currentValues = data(i).values; result(i) = sum(currentValues); end end ``` But I still receive the same behavior. I suspect it might have to do with how the `values` are structured when they have different lengths. I need to find a way to handle cases where `values` might not be present or have varying lengths without working with this behavior. Any suggestions on how to resolve this scenario or best practices for working with nested structs in MATLAB would be greatly appreciated. I'm coming from a different tech stack and learning Matlab. How would you solve this? The stack includes Matlab and several other technologies. Thanks in advance!