"Access Elements of a Nonscalar Structure Array" issue
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Hello,
I try to access data stored in a structure of this type:
I would love to have access easily for exemple to all the masses of all the subsystems, but i cannot manage to do it , i tried : (I pasted the full code at the end)
systems(:).subsystem.mass
but it returned: Reference to non-existent field 'subsystem'.
The real problem has a lot more system than that, do you have an idea on how i could access to all the masses contained in all the subsystems?
Thank you for your help!
I tried to follow this MatLab tutorial but it doesn't seem to work in my case:
clear all
clc
%% creation of the structure
systems=struct();
system1.mass=1000;
system1.CG=[0,1,2];
system1.subsystem.mass=[0;10;100];
system1.subsystem.CG=[0,1,2;3,4,5;6,7,8];
systems.system1=system1;
system2.CG=[0,1,2];
system2.mass=1000;
system2.subsystem.mass=[0;10;100];
system2.subsystem.CG=[0,1,2;3,4,5;6,7,8];
systems.system2=system2;
systems.mass=5000;
systems.CG=[10,20,30];
clear system1
clear system2
%% access to data
systems(:).subsystem.mass
댓글 수: 2
Stephen23
2021년 6월 7일
편집: Stephen23
2021년 6월 7일
Why do you need to brutally CLEAR ALL cached functions from memory?
Is there a reason you cannot just use much more gentle CLEARVARS?
You did not create any non-scalar structures, so the documentation you linked to is not relevant:
isscalar(systems)
isscalar(systems.system1)
isscalar(systems.system2)
Possibly you are confusing the size of a structure with how many fields a structure has (whereas in fact these are totally independent from each other). The design of your scalar structures with multiuple fields does not offer any obvious trivial way to access the nested structures.
채택된 답변
Jan
2021년 6월 7일
You cannot access fields of deeply nested structs in Matlab. You need a loop to do this.
댓글 수: 2
Jan
2021년 6월 7일
Hiding an index in the fieldname as in "system1" is a bad idea. Deeply nested structs are inefficient also, if you need to access nested fields. So restructuring the data might be the best approach.
추가 답변 (1개)
Stephen23
2021년 6월 7일
편집: Stephen23
2021년 6월 7일
sys = fakedata()
fnm = regexp(fieldnames(sys),'^system\d+$','match');
fnm = [fnm{:}]
fun = @(f)sys.(f).subsystem.mass;
out = cellfun(fun,fnm,'uni',0)
Checking (tip for the future: using different values for fake data is a simple sanity check):
out{1}
out{2}
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