How to sum the values of a fieldname of struct

Hello! I have a struct 'STC_ORE', and I want to calculate the values of fieldname' ORE_TON', so I want a code, but there are some errors. Therefore, could you please give me some solutions to deal with it, thanks!

for ii = 1:size(rock_code,1)
if ~isempty(STC_ORE(ii).ORE_TON)
A=sum([STC_ORE(:).ORE_TON]);
end
end

Answer 1

[Image Analyst]

You need to add the sum onto the prior value of the sum:

theSum = 0; % Initialize
for ii = 1:size(rock_code,1)
	if ~isempty(STC_ORE(ii).ORE_TON)
		theSum =  theSum + sum([STC_ORE(:).ORE_TON]); % Add onto running total.
	end
end

If you need more help, or that doesn't work, attach STC_ORE in a .mat file.

[Chao Zhang]

theSum = theSum + sum([STC_ORE(ii).ORE_TON]) might works well

[Image Analyst]

Yeah, but it's not a bad idea to check like you did. Sometimes doing math on null/empty or NaN values will throw an error or make the whole thing be NaN.