Range intersection

Mathematical intersection of range composed of a union of intervals

Description

Purpose: Range/interval intersection

A and B two ranges of closed intervals written
as vectors [lowerbound1 upperbound1 lowerbound2 upperbound2]
or as matrix
[lowerbound1, lowerbound2, lowerboundn;
 upperbound1, upperbound2, upperboundn]
A and B have to be sorted in ascending order

out is the mathematical intersection A n B

EXAMPLE USAGE:
  >> out=range_intersection([1 3 5 9],[2 9])
    out = [2 3 5 9]
   >> out=range_intersection([40 44 55 58], [42 49 50 52])
   out = [42 44]

Acknowledgements

Interval Merging inspired this file.

• MATLAB release: MATLAB 7.8 (R2009a)

[Bruno Luong]

Good coding, fast

[Per]

Really useful for me.

[Xavier Xavier]

Yes, I wanted a fast code so the input should be correct. I don't check neither that AB are sorted in ascending order.

[Aurelien Queffurust]

One more test could be added:
x1 = [0 10 16 20 ]
x2 = [ 3 5 15 19 25]
-> out = 3 5 16 19

now if x1 has one more value :
x1 = [0 10 16 20 26]
you get :
Attempted to access first(2); index out of bounds because numel(first)=1.

Error in range_intersection (line 35)
if first(2)<second(1)

The test would be to check that the input vector are divisible by 2 ?

[Aurelien Queffurust]

Since the bug has been fixed on 30 May 2012 , I use range_intersection . It works like a charm and is definetely faster than other FEx MergeBrackets.m (Interval merging by Bruno Luong)

[Xavier Xavier]

The file has been modified to remove the bug. Now I make sure that 'first' is ahead 'second'.

[Shaohan Hu]

buggy? e.g. produces bad results on ([40 44 55 58], [42 49 50 52]); seems like you didn't make sure 'first' being ahead of 'second' for each iteration

[BD Knight]

 

[Xavier Xavier]

Yes you are right, I modified the comments

Thx

[Brian B]

Helpful function, but I believe the second form of the input should be
[lowerbound1, lowerbound2, lowerboundn;
upperbound1, upperbound2, upperboundn]
instead of what is shown in the comments.

Compare the following:
range_intersection([1 3 4 5],[3 4])
range_intersection([1 3; 4 5],[3 4])
range_intersection([1 3; 4 5]',[3 4])

Thanks for sharing this.

-b