Simple Vector Indexing Question

Say I have a vector called Vector that is roughly a 6000x50 double.

I want to pull out certain indexes from that double, deleting the rows that are not in the following start - stop table, like this:

Random Example below:

Start Stop

540 1238

1423 2144

2403 3280

3485 4385

4573 5152

So I want all the data from rows 540 -1238, rows 1423-2144, 2403-3280, 3485-4385, and 4573-5152. I want to delete the rows before 540, after 5152, and in between these windows (i.e. 1238 to 1434).

There must be a simple way to do this, I have been making it way too complicated.

activeVector = Vector ([540:1238]; [1423:2144]; ... etc.

Please let me know if you can help!

[Walter Roberson]

In MATLAB terminology, "vector" is always 1 x something or something x 1. Something that is 6000 x 50 would be called either a "matrix" or an "array"

Answer 1

[Star Strider]

Put all the indices inside one set of square brackets —

Vector = 1:20;
activeVector = Vector([3:7 10:15])

activeVector = 1×11

3 4 5 6 7 10 11 12 13 14 15

This is a simplified version of what you want to do.

EDIT — (4 Oct 2023 at 17:52)

To delete rows from a matrix, this works similarly —

Matrix = Vector(:)*ones(1,10)

Matrix = 20×10

1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 10 10 10 10 10 10 10 10 10 10

activeMatrix = Matrix([3:7 10:15],:)

activeMatrix = 11×10

3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 10 10 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 12 13 13 13 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 14

.

Answer 2

[Voss]

M = rand(6000,5);

rows = [
    540  	1238
    1423	2144
    2403	3280
    3485	4385
    4573	5152];

idx = arrayfun(@colon,rows(:,1),rows(:,2),'UniformOutput',false);

M = M([idx{:}],:);