How to save output from iteration?
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i have an array a=[1;2;2;3;4;4;4;4]; when i type
for i=1:3
[~,col]=find(a==1)
end
it only results col=1, i wanna save all of the col, it's like
col=1
1
1
what should i do? thank you
2 Comments
Leah
on 22 Apr 2013
it's not clear what you are looping over since "i" does not appear inside the for loop. Also your desired output for col, doesn't really make sense since 1 only appears in the first entry of a. What do the three outputs for col mean?
Matt Kindig
on 22 Apr 2013
@Tara: For what it's worth, you can accomplish the same thing more efficiently by using ismember(), as:
[temp,locs]=ismember(a, 1:3);
% 'locs' will contain positions where 1,2,and 3 are found in 'a'
Answers (1)
Walter Roberson
on 22 Apr 2013
for i = 1 : 3
[~, col{i}] = find(a==1);
end
Notice the switch to cell arrays. This is needed because any given value might occur 0, 1, or many times instead of exactly once.
Also notice you are doing exactly the same "find" each time. Perhaps you wanted to find over a(i,:) ?
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