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: armacls

Quantlet: armalik
Description: estimates an ARMA(1,1) process with mean zero by maximum likelihood using the innovation algorithm

Reference(s):

Usage: y = armalik(x)
Input:
x n-vector, the process
Output:
y list containing 1. the estimated parameters, 2. the corresponding asymptotic standard deviations, 3. the asymptotic covariance, and 4. the estimate of the white noise variance

Example:
library("times")                     ; Loads the quantlets from Times Library
randomize(0)                         ; Sets random seed
x = genarma(0.7,0.3,normal(100))     ; Generates ARMA(p,q) with White Noise
timeplot(x,100)                     ; Plots the ARMA process in a single display
{a, stderr, covp, s2} = armalik(x)   ; Estimation procedure for ARMA(1,1) process
z=(a)|(stderr)|(covp)|(s2)           ; Estimation output
z

Result:
Contents of z                        ; Vector of parameter Estimates
[1,]  0.87487                        ; AR(1)
[2,] -0.069252                       ; MA(1)
[3,]  0.056481                       ; Corresponding Standard Error
[4,]  0.11633                        ; Corresponding Standard Error
[5,] -0.0033796                      ; Corresponding Asymptotic Convariance
[6,]    1.023                        ; Estimate of White Noise Variance
"For reading convenience the graphical output has been omitted."
Example:
library("times")                     ; Loads the quantlets from Times Library
randomize(101)                       ; Sets random seed
dax=read("dax")                      ; monthly DAX 1979:1-2000:10
daxreturn=tdiff(log(dax))           ; generates the monthly return
timeplot(daxreturn,261)             ; Plots the monthly return series for DAX
{a, stderr, covp, s2} = armalik(daxreturn)   ; Estimation procedure for return process
z=(a)|(stderr)|(covp)|(s2)           ; Estimation output
z

Result:
Contents of z                        ; Vector of parameter Estimates
[1,] -0.066774                       ; AR(1)
[2,]  0.088562                       ; MA(1)
[3,]   2.8178                        ; Corresponding Standard Error
[4,]   2.8131                        ; Corresponding Standard Error
[5,]  -7.9248                        ; Corresponding Asymptotic Convariance
[6,]  0.0032548                      ; Estimate of White Noise Variance
"For reading convenience the graphical output has been omitted."



Author: C. Hafner, W. Haerdle, 19960906, G. Aydinli, 20010419 license MD*Tech
(C) MD*TECH Method and Data Technologies, 05.02.2006