Hi guys, I am starting to study about time-series analysis... I am now in the Pearson coefficient of autocorrelation... Is this the same with the ACF() function? I have the following from a manual, but I don't understand how they got the output (located at the bottom). Can you guys tell me how they got

Here are the details:

Function: acf()

Purpose Computes sample autocorrelations.

Format rk = acf(y,k,d);

y Nx1 vector, data.

k scalar, maximum number of autocorrelations to compute.

d scalar, order of differencing.

I have the following data:

x = { 20.80,

18.58,

23.39,

20.47,

21.78,

19.56,

19.58,

18.91,

20.08,

21.88 };

rk = acf(x,4,2);

print rk;

OUTPUT:

-0.74911771

0.48360914

-0.34229330

0.17461180

I would appreciate some help.