How to remove sets of values from a column vector using two column vectors with the starting and stopping indeces for removal by row

Let's say that I have a column vector, x

x = (1:10)'

and two column vectors with the starting and stopping indeces, x_start and x_stop

x_start = [2; 7]
x_stop = [5; 8]

such that I want to remove the values 2->5 and 7->8.

I could use a simple for loop, such as the following:

for i = length(x_start):1
a = x_start(i)
b = x_stop(i)
x(a:b) = []
end

However, I would look to avoid using a for loop as my vector lengths are on the order of 10^5. Is there a more computationally efficient manner to build the indeces that I want to remove from my starting and stopping vectors?

[Fangjun Jiang]

There is a typo. Should be

for i = length(x_start):-1:1

[Shawn]

Ah yes, you are correct. Thanks for noting that.

Answer 1

[Fangjun Jiang]

This method uses string. Not sure if it is more efficient.

num=[x_start,x_stop]';
str=sprintf('%d:%d,',num(:));
x(str2num(str))=[];

[Shawn]

This is an interesting answer, but it does not seem to be working for length(x_start)~=2.

If I use x_start and x_stop with length 3 as:

x_start = [1,4,9]
x_stop = [2,7,10]

Then I return x = [5,6], but it should return x = [3,8] if I am removing 1->2, 4->7, and 9->10.

In this case, str = '1:4,9:2,7:10' rather than '1:2,4:7,7:10'. It does work on the length 2 case, but that was just pseudo-code to explain the problem. The actual vectors are much larger. Can this approach be expanded to account for that?

[Shawn]

I apologize, I forgot to transpose the x_start and x_stop vectors. The code seems to be running well. Thanks!