Fastest way to cycle through a structure for a number
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
Will Kinsman
am 1 Aug. 2016
Kommentiert: Stephen23
am 2 Aug. 2016
given: a structure and a double
return: the index of a structure that has that number
data:
structure(1).val = 50
structure(2).val = 47
structure(3).val = 22
given: structure, 50
return: 1
given: structure, 22
return: 3
% my attempt
function y = return_struct_index(structure,inputval)
for i = 1:length(structure)
if structure(i).val==inputval
y = i;
return
end
end
y = [];
This is rather slow and comes in at about 2.5 seconds for 1000 iterations for my code. I know for a fact there is a faster way to do this but haven't been able to track it down. Obviously I haven't vectored my function. I have also tried converting the structure to a cell array and then vectoring the solution, but the conversion makes it even slower.
Help greatly appreciated!!
Will
1 Kommentar
Stephen23
am 2 Aug. 2016
If there are non-scalar arrays in the field val:
S(1).val = 50;
S(2).val = 47;
S(3).val = [23,5];
fun = @(n)find(arrayfun(@(s)any(s.val(:)==n),S));
>> fun(22)
ans =
Empty matrix: 1-by-0
>> fun(23)
ans =
3
Akzeptierte Antwort
James Tursa
am 1 Aug. 2016
Bearbeitet: James Tursa
am 1 Aug. 2016
result = find([structure.val]==value);
E.g.,
>> structure(1).val = 50;
>> structure(2).val = 47;
>> structure(3).val = 22;
>> find([structure.val]==50)
ans =
1
>> find([structure.val]==47)
ans =
2
>> find([structure.val]==22)
ans =
3
>> find([structure.val]==99)
ans =
Empty matrix: 1-by-0
1 Kommentar
Weitere Antworten (1)
Azzi Abdelmalek
am 1 Aug. 2016
s(1).val = 50
s(2).val = 47
s(3).val = 22
find([s(:).val]==50)
0 Kommentare
Siehe auch
Kategorien
Mehr zu Characters and Strings finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!