# sort vector elements under given restrictions

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oxy on 19 Mar 2014
Commented: zepp on 20 Mar 2014
Hi guys,
i have the vector v=[1 2 3 4 5]
wanna resort it so that v(3) and v(5) comes first:
v=[3 5 others] % 'others' has any order
How can i do that? The problem here is exactly this: how to write 1:5 but missing 3 and 5 .
Any idea? thx...
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PS: this question is related to
The point relating to this cited question is that i can find all combinations (just for-loop), but i cannot arrange the rest of the dimensions. Thus this present question.
Thx...

zepp on 19 Mar 2014
You can create a logical array (same length as v) with 1's for the positions you want (say, 3 and 5) and 0's for the rest and use that to refer to the indices.
v = [1 2 3 4 5]
ind = [0 0 1 0 1]
v = [v(ind==1) v(~ind==1)]

oxy on 20 Mar 2014
Edited: oxy on 20 Mar 2014
Great! Thx!
Just another question: This is the way I've been doing it on octave. I wander why it doesnt work in matlab!!! :-/
vector2sort= 1:6
n=length(vector2sort)
a=2; b=4 % i.e. I wanna the 2nd and 4th elements of vector2sort first
[a b (1:n)( (1:n)!=a & (1:n)!=b )] % this is how we sort it
Why it does not work in matlab?!! Is there a way to do it more simila?

#### 1 Comment

zepp on 20 Mar 2014
The concept is fine, but you can't reference array elements like that in Matlab.
Try this out:
v = 1:6;
a = 2; b = 4;
sortedv = [a b v(v~=a & v~=b)];