Date: May 8, 2013 11:45 PM
Author: dpb
Subject: Re: Stupid question ;)
On 5/8/2013 10:10 PM, SK wrote:

> Hi,

>

> I have a simple question but I did not manage to find the solution.

> I am working on some block bootstrap resampling methods, and I need to

> take a vector x with some data and divide it into blocks and then

> resample these blocks.

>

> Let me show you one on simple example

>

> step 1 : I take x = [ 1:20 ]

> step 2 : I created a matlab function that give me these blocks from x;

> u =

>

> 1 4 7 10 13 16

> 2 5 8 11 14 17

> 3 6 9 12 15 18

>

> step 3: I want now to create a vector or a matrix named B with

> B(1)=u(:,1)

> B(2)=u(:,2)

> B(3)=u(:,3)

> B(4)=u(:,4)

> B(5)=u(:,5)

> B(6)=u(:,6)

>

> How to create B?

>

> When I will have B, I will just create a lot of resamples with

> replacement of these blocks

> for example X = [ B(1) B(1) B(6) B(4) B(3) B(1)]

Just like you wrote it---but there's really no need; just use

X = [u(:,randperm(size(u,2)))];

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