may i ask how to sort the row of matrix in large data?

may i ask how to sort the row of matrix in large data? For example, there are 28694 rows... how I arrange the rows according my own number?

a=[a0, a1,................,a28694]

Let say I want arrange in

b=[a4,a5,a28694,.......,a2,a56,a34]

is that possible arrange like this?

[CS Researcher]

How do you define your own numbers? Is it random? Is there a pattern?

[loong seow li]

it is a array from other data...

Answer 1

[Azzi Abdelmalek]

a=[10 20 4 5]
idx=[2 1 3 4]
out=a(idx)

[loong seow li]

if is large value? For example I have column 1 until column 100.. how I rearrange the order of column?

[Azzi Abdelmalek]

You have to define the new order.

[loong seow li]

thanks a lot