Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Library: times
See also: roblm lobrob gph lo kpss rvlm pgram

Quantlet: robwhittle
Description: Semiparametric Gaussian estimator of the degree of long memory of a time series, based on the Whittle estimator. The first argument is the series, the second argument is the vector of bandwidths, i.e., the number of frequencies after zero that are considered. By default, the bandwidth vector m = n/4, n/8, n/16, where n is the sample size. This quantlet displays the estimated parameter d, with the number of frequencies considered.

Reference(s):

Usage: d = robwhittle(x{,bdvec})
Input:
x vector
bdvec vector of bandwidths
Output:
d vector

Example:
;nonparametric estimation of degree of long-memory in volatility
;Since no vector of bandwidths is provided, the default vector of
;bandwidth parameter is used.
library("times")
x = read("dmus58.dat")
x=x[1:1000]
y = abs(tdiff(x))
d = robwhittle(y)
d

Result:
Contents of d

[1,] "     d     Bandwidth"
[2,] "_____________________"
[3,] ""
[4,] "  0.0982      250"
[5,] "  0.1200      125"
[6,] "  0.0805       62"
Example:
;nonparametric estimation of degree of long-memory in volatility
;In this case, the vector of bandwidths m is provided
library("times")
x = read("dmus58.dat")
x=x[1:1000]
y = abs(tdiff(x))
m = #(50,100,150)
d = robwhittle(y,m)
d

Result:
Contents of d

[1,] "     d     Bandwidth"
[2,] "_____________________"
[3,] ""
[4,] "  0.0669       50"
[5,] "  0.0940      100"
[6,] "  0.1269      150"



Author: G. Teyssiere, 19981210 license MD*Tech
(C) MD*TECH Method and Data Technologies, 05.02.2006