| Version: | 0.7-5 | 
| Date: | 2022-04-27 | 
| Type: | Package | 
| Title: | Generalized Orthogonal GARCH (GO-GARCH) Models | 
| Description: | Provision of classes and methods for estimating generalized orthogonal GARCH models. This is an alternative approach to CC-GARCH models in the context of multivariate volatility modeling. | 
| Depends: | R (≥ 2.10.0), methods, stats, graphics, fGarch, fastICA | 
| License: | GPL-2 | GPL-3 [expanded from: GPL (≥ 2)] | 
| LazyLoad: | yes | 
| Author: | Bernhard Pfaff [aut, cre] | 
| Maintainer: | Bernhard Pfaff <bernhard@pfaffikus.de> | 
| Repository: | CRAN | 
| Repository/R-Forge/Project: | gogarch | 
| Repository/R-Forge/Revision: | 61 | 
| Repository/R-Forge/DateTimeStamp: | 2022-04-27 18:46:09 | 
| Date/Publication: | 2022-04-29 16:00:02 UTC | 
| NeedsCompilation: | no | 
| Packaged: | 2022-04-27 18:53:22 UTC; rforge | 
Dow Jones Industrial Average and Nasdaq stock indices
Description
Levels of the Dow Jones Industrial Average and NASDAQ stock indices for the period 03/23/1990 until 03/23/2000.
Usage
data(BVDW)Format
A data frame with 2610 observations on the following 3 variables.
- Date
- Date in the format YYYYMMDD. 
- DJIA
- Level of the DIJA. 
- NASDAQ
- Level of the NASDAQ. 
Details
This data set has been utilized in the source below and was kindly provided by Roy van der Weide.
Source
Boswijk, H. Peter and van der Weide, Roy (2006), Wake me up before you GO-GARCH, Tinbergen Institute Discussion Paper, TI 2006-079/4, University of Amsterdam and Tinbergen Institute.
See Also
Examples
data(BVDW)
str(BVDW)
Stock prices transportation sector, oil and kerosene prices
Description
This data frame contains the stock prices from American Airlines, South-West Airlines, Boeing and FedEx. In addition the spot prices for crude oil and kerosene are included. This data set was used in the article by Boswijk and van der Weide (2009). The data range is from July, 19 1993 until August, 12 2008.
Usage
data(BVDWAIR)Format
A data frame with 3791 observations on the following 7 variables.
- Date
- POSIXt: The dates of observations. 
- CrudeOil
- Crude oil price. 
- Kerosene
- Kerosene price. 
- AmericanAir
- Stock prices of American Airlines. 
- SouthWest
- Stock prices of South-West Airlines. 
- Boeing
- Stock prices of Boeing. 
- FedEx
- Stock prices of Boeing. 
Details
The stock price data was downloaded from Yahoo Finance and the price series for crude oil and kerosene were obtained from the U.S. Energy Information Administration (EIA).
Source
References
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
Examples
data(BVDWAIR)
str(BVDWAIR)
Sector indices of the EURO STOXX 600
Description
The data frame contains the following sector indices of the EURO STOXX 600 index: Automobiles \& Parts, Banks, Basic Resources, Chemicals, Construction and Materials, Financial Services, Food \& Beverages, Health Care, Industrial Goods \& Services, Insurance, Media, Oil \& Gas, Technology, Telecommunications and Utilities. The data range is from 31th December 1986 until 21st November 2008.
Usage
data(BVDWSTOXX)Format
A data frame with 5652 observations on the following 16 variables.
- Date
- POSIXt: The dates of observations. 
- AutoParts
- Sector index Automobiles \& Parts 
- Banks
- Sector index Banks 
- BasicRes
- Sector index Basic Resources 
- Chemicals
- Sector index Chemicals 
- ConstrMat
- Sector index Construction and Materials 
- FoodBeverage
- Sector index Food \& Beverages 
- FinService
- Sector index Financial Services 
- HealthCare
- Sector index Health Care 
- IndustrialGoods
- Sector index Industrial Goods \& Services 
- Insurance
- Sector index Insurance 
- Media
- Sector index Media 
- OilGas
- Sector index Oil \& Gas 
- Technology
- Sector index Technology 
- Telecom
- Sector index Telecommunications 
- Utilities
- Sector index Utilities 
Source
References
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
Examples
data(BVDWSTOXX)
str(BVDWSTOXX)
Class "GoGARCH": Estimated GO-GARCH Models
Description
This class defines the slots for estimated GO-GARCH models. It
contains the class Goinit. 
Objects from the Class
Objects can be created by calls of the form new("GoGARCH", ...). 
Slots
- Z:
- Object of class - "matrix": Transformation matrix.
- U:
- Object of class - "Orthom": Orthonormal matrix.
- Y:
- Object of class - "matrix": Extracted component matrix.
- H:
- Object of class - "list": List of conditional variance/covariance matrices.
- models:
- Object of class - "list": List of univariate GARCH model fits.
- estby:
- Object of class - "character": Estimation method.
- CALL:
- Object of class - "call": Result of- match.callin generating function.
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Extends
Class "Goinit", directly.
Methods
- cvar
- Returns the conditional variances as object with class attribute - "mts" "ts".
- ccov
- Returns the conditional co-variances as object with class attribute - "mts" "ts".
- ccor
- Returns the conditional correlationsas object with class attribute - "mts" "ts".
- coef
- Returns the coeffiecients of the component GARCH models. 
- converged
- Returns the convergence codes of the component GARCH models. 
- formula
- Returns the formula for the component GARCH models. 
- plot
- Plotting of the conditional correlations. 
- predict
- Returns the conditional covariances and mean forecasts and the forecasts of the component GARCH models, object is of class - Gopredict.
- residuals
- Returns the residuals of the GO-GARCH model. 
- show
- show-method for objects of class - GoGARCH.
- summary
- summary-method for objects of class - GoGARCH, object is of class- Gosum.
- update
- Updates an object of class - GoGARCH.
Author(s)
Bernhard Pfaff
See Also
Class "Goestica": GO-GARCH models estimated by fast ICA
Description
This class contains the GoGARCH class and has the mixing matrix
A as additional slot.
Objects from the Class
Objects can be created by calls of the form new("Goestmm", ...),
or with the function gogarch whereby method = "ica" has
been set.  
Slots
- ica:
- Object of class - "list": List object returned by- fastICA.
- Z:
- Object of class - "matrix": Transformation matrix.
- U:
- Object of class - "matrix": Orthogonal matrix.
- Y:
- Object of class - "matrix": Extracted component matrix.
- H:
- Object of class - "list": List of conditional variance/covariance matrices.
- models:
- Object of class - "list": List of univariate GARCH model fits.
- estby:
- Object of class - "character": Estimation method.
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Extends
Class "GoGARCH", directly.
Class "Goinit", by class "GoGARCH", distance 2.
Methods
- cvar
- Returns the conditional variances as object with class attribute - "mts" "ts".
- ccov
- Returns the conditional co-variances as object with class attribute - "mts" "ts".
- ccor
- Returns the conditional correlationsas object with class attribute - "mts" "ts".
- coef
- Returns the coeffiecients of the component GARCH models. 
- converged
- Returns the convergence codes of the component GARCH models. 
- formula
- Returns the formula for the component GARCH models. 
- goest
- Fast ICA estimation of Go-GARCH models. 
- plot
- Plotting of the conditional correlations. 
- predict
- Returns the conditional covariances and mean forecasts and the forecasts of the component GARCH models, object is of class - Gopredict.
- residuals
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- resid
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- show
- show-method for objects of class - Goestmm.
- summary
- summary-method for objects of class - Goestml, object is of class- Gosum.
- update
- Updates an object of class - Goestml.
Author(s)
Bernhard Pfaff
References
Broda, S.A. and Paolella, M.S. (2008): CHICAGO: A Fast and Accurate Method for Portfolio Risk Calculation, Swiss Finance Institute, Research Paper Series No. 08-08, Zuerich.
See Also
GoGARCH, Goinit,
Gosum, Gopredict,
goest-methods and gogarch
Class "Goestml": GO-GARCH models estimated by Maximum-Likelihood
Description
This class contains the GoGARCH class and has the
outcome of nlminb as an additional slot.
Objects from the Class
Objects can be created by calls of the form new("Goestml",
  ...), or with the function gogarch whereby method =
  "ml" has been set.  
Slots
- opt:
- Object of class - "list": List returned by- nlminb.
- Z:
- Object of class - "matrix": Transformation matrix.
- U:
- Object of class - "matrix": Orthogonal matrix.
- Y:
- Object of class - "matrix": Extracted component matrix.
- H:
- Object of class - "list": List of conditional variance/covariance matrices.
- models:
- Object of class - "list": List of univariate GARCH model fits.
- estby:
- Object of class - "character": Estimation method.
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Extends
Class "GoGARCH", directly.
Class "Goinit", by class "GoGARCH", distance 2.
Methods
- angles
- Returns the Eulerian angles. 
- cvar
- Returns the conditional variances as object with class attribute - "mts" "ts".
- ccov
- Returns the conditional co-variances as object with class attribute - "mts" "ts".
- ccor
- Returns the conditional correlations as object with class attribute - "mts" "ts".
- coef
- Returns the coeffiecients of the component GARCH models. 
- converged
- Returns the convergence codes of the component GARCH models. 
- formula
- Returns the formula for the component GARCH models. 
- goest
- ML-Estimation of Go-GARCH models. 
- logLik
- Returns the value of the log-Likelihood function. 
- plot
- Plotting of the conditional correlations. 
- predict
- Returns the conditional covariances and mean forecasts and the forecasts of the component GARCH models, object is of class - Gopredict.
- residuals
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- resid
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- show
- show-method for objects of class - Goestml.
- summary
- summary-method for objects of class - Goestml, object is of class- Gosum.
- update
- Updates an object of class - Goestml.
Author(s)
Bernhard Pfaff
See Also
GoGARCH, Goinit,
Gosum, Gopredict,
goest-methods
Class "Goestmm": Go-GARCH models estimated by Methods of Moments
Description
This class contains the GoGARCH class and has the weights
vector and the matched orthogonal matrices U as additional
slots.
Objects from the Class
Objects can be created by calls of the form new("Goestmm", ...),
or with the function gogarch whereby method = "mm" has
been set.  
Slots
- weights:
- Object of class - "numeric": Weights for aggregating the matched orthogonal matrices- U.
- Umatched:
- Object of class - "list": List of matched orthogonal matrices- U.
- Z:
- Object of class - "matrix": Transformation matrix.
- U:
- Object of class - "matrix": Orthogonal matrix.
- Y:
- Object of class - "matrix": Extracted component matrix.
- H:
- Object of class - "list": List of conditional variance/covariance matrices.
- models:
- Object of class - "list": List of univariate GARCH model fits.
- estby:
- Object of class - "character": Estimation method.
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Extends
Class "GoGARCH", directly.
Class "Goinit", by class "GoGARCH", distance 2.
Methods
- cvar
- Returns the conditional variances as object with class attribute - "mts" "ts".
- ccov
- Returns the conditional co-variances as object with class attribute - "mts" "ts".
- ccor
- Returns the conditional correlationsas object with class attribute - "mts" "ts".
- coef
- Returns the coeffiecients of the component GARCH models. 
- converged
- Returns the convergence codes of the component GARCH models. 
- formula
- Returns the formula for the component GARCH models. 
- goest
- Methods of moments estimation of Go-GARCH models. 
- plot
- Plotting of the conditional correlations. 
- predict
- Returns the conditional covariances and mean forecasts and the forecasts of the component GARCH models, object is of class - Gopredict.
- residuals
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- resid
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- show
- show-method for objects of class - Goestmm.
- summary
- summary-method for objects of class - Goestml, object is of class- Gosum.
- update
- Updates an object of class - Goestml.
Author(s)
Bernhard Pfaff
References
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
See Also
GoGARCH, Goinit,
Gosum, Gopredict,
goest-methods, gogarch,
Umatch
Class "Goestnls": GO-GARCH models estimated by Non-linear Least-Squares
Description
This class contains the GoGARCH class and has the
outcome of optim as an additional slot.
Objects from the Class
Objects can be created by calls of the form new("Goestnls", ...), 
or with the function gogarch whereby method = "nls" has
been set. 
Slots
- nls:
- Object of class - "list": List returned by- optim.
- Z:
- Object of class - "matrix": Transformation matrix.
- U:
- Object of class - "matrix": Orthogonal matrix.
- Y:
- Object of class - "matrix": Extracted component matrix.
- H:
- Object of class - "list": List of conditional variance/covariance matrices.
- models:
- Object of class - "list": List of univariate GARCH model fits.
- estby:
- Object of class - "character": Estimation method.
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Extends
Class "GoGARCH", directly.
Class "Goinit", by class "GoGARCH", distance 2.
Methods
- cvar
- Returns the conditional variances as object with class attribute - "mts" "ts".
- ccov
- Returns the conditional co-variances as object with class attribute - "mts" "ts".
- ccor
- Returns the conditional correlationsas object with class attribute - "mts" "ts".
- coef
- Returns the coeffiecients of the component GARCH models. 
- converged
- Returns the convergence codes of the component GARCH models. 
- formula
- Returns the formula for the component GARCH models. 
- goest
- NLS-Estimation of Go-GARCH models. 
- plot
- Plotting of the conditional correlations. 
- predict
- Returns the conditional covariances and mean forecasts and the forecasts of the component GARCH models, object is of class - Gopredict.
- residuals
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- resid
- Returns the residuals of the Go-GARCH model as object with class attribute - "mts" "ts".
- show
- show-method for objects of class - Goestnls.
- summary
- summary-method for objects of class - GoGARCH, object is of class- Gosum.
- update
- Updates an object of class - GoGARCH.
Author(s)
Bernhard Pfaff
See Also
GoGARCH, Goinit,
Gosum, Gopredict,
goest-methods, gogarch
Class "Goinit": Initialisation of GO-GARCH models
Description
This class defines the required slots for estimating GO-GARCH models.
Objects from the Class
Objects can be created by calls of the form new("Goinit", ...),
or more conveniently by goinit(). 
Slots
- X:
- Object of class - "matrix": The data matrix.
- V:
- Object of class - "matrix": Covariance matrix of- X.
- P:
- Object of class - "matrix": Left singular values of Var/Cov matrix of- X.
- Dsqr:
- Object of class - "matrix": Square roots of eigenvalues on diagonal, else zero.
- garchf:
- Object of class - "formula": Garch formula used for uncorrelated component GARCH models.
- name:
- Object of class - "character": The name of the original data object.
Methods
- show
- Prints the slots, whereby for - Xonly the head is displayed.
Author(s)
Bernhard Pfaff
See Also
Examples
showClass("Goinit")
Class "Gopredict": Prediction of GO-GARCH Models
Description
This class defines the slots for forecasts from a GO-GARCH model.
Objects from the Class
Objects can be created by calls of the form new("Gopredict",
  ...), or with the method predict of formal class objects
GoGARCH and Goestml.   
Slots
- Hf:
- Object of class - "list": The forecasted conditional covariances.
- Xf:
- Object of class - "matrix": The transformed forecasts of the component GARCH mean models.
- CGARCHF:
- Object of class - "list": The original forecasts of the component GARCH models.
Methods
- ccor
- Returns the forecasted conditional correlations. 
- ccov
- Returns the forecasted conditional co-variances. 
- cvar
- Returns the forecasted conditional variances. 
- show
- show-method for objects of class - Gopredict.
Note
In case more than 10 forecasts steps are computed, the
show-method displays only the head of the returned
objects. Furthermore, the show-method displays the forecasted
conditional variances only. The forecasted conditional co-variances
and/or the forecasted conditional correlations can be retrieved with
the methods ccov or ccor, respectively.
Author(s)
Bernhard Pfaff
See Also
Class "Gosum": Summary object of GO-GARCH model
Description
The formal summary class of GoGARCH objects or objects that
extend this class.
Objects from the Class
Objects can be created by calls of the form new("Gosum", ...)
or are set by the summary-method. 
Slots
- name:
- character: the name of the original data object.
- method:
- character: the estimation method.
- model:
- formula: The GARCH model formula for the component GARCH models.
- garchc:
- list: The elements are- matcoefmatrices generated by- garchFitfor the components.
- Zinv:
- matrix: The inverse of the linear map- X = Y Z.
Methods
- show
- show-method for objects of class - Gosum.
Author(s)
Bernhard Pfaff
See Also
Class "Orthom": Orthogonal matrices
Description
This class defines an orthogonal matrix, which is characterized by
det(M) = 1 and M M' = I.
Objects from the Class
Objects can be created by calls of the form new("Orthom",
  ...). In addition the function UprodR returns an object of
formal class Orthom.
Slots
- M:
- Object of class - "matrix".
Methods
- M
- Returns the slot - Mof class- Orthom.
- print-method for objects of class - Orthom.
- show
- show-method for objects of class - Orthom.
- t
- Transpose of - object@M.
Note
Objects are validated by validOrthomObject(). This function
is utilised by validObject().
Author(s)
Bernhard Pfaff
See Also
Examples
showClass("Orthom")
Rotation matrix, 2-dimensional
Description
Given an angle \theta whereby \theta \in [0, \pi/2) the
function Rd2 returns a 2-dimensional rotation matrix of Euler angles.  
Usage
Rd2(theta)
Arguments
| theta | Numeric, angle in the interval  | 
Value
| R | A 2-dimensional rotation matrix. | 
Author(s)
Bernhard Pfaff
See Also
Examples
Rd2(pi/3)
Matching of Orthogonal Matrices for Cayley transforms
Description
This function matches an orthogonal matrix to the importance of the columns of the matrix to which it should be matched.
Usage
Umatch(from, to)
Arguments
| from | Matrix: orthogonal | 
| to | Matrix: orthogonal | 
Value
| mat | Matched matrix. | 
Author(s)
Bernhard Pfaff
References
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
Liebeck, H. and Osborne, A. (1991), The Generation of All Rational Orthogonal Matrices, The American Mathematical Monthly, 98 (2) (Feb. 1991), 131 – 133.
See Also
Creation of an orthogonal matrix
Description
This function returns an orthogonal matrix which results of the matrix products of rotation matrices.
Usage
UprodR(theta)
Arguments
| theta | Vector, of angles of the rotation matrices. | 
Details
The length of theta must be equal to m * (m - 1) / 2,
where m is the dimension of the orthogonal matrix. The elements
of theta must lie in the interval [0, \pi/2). 
Value
| result | Object of class  | 
Author(s)
Bernhard Pfaff
References
Vilenkin, N. Ja. (1968), Special Functions and the Theory of Group Representations, Translations of Mathematical Monographs, 22, American Math. Soc., Providence, Rhode Island, USA.
See Also
Examples
theta <- c(pi/3, pi/5, pi/7)
U <- UprodR(theta)
U
Dow Jones Industrial Average and Nasdaq stock indices
Description
The daily (log) returns of the Dow Jones Industrial Average and the NASDAQ composite, respectively. The daily observations start at the first of January, 1990, and end in October 2001.
Usage
data(VDW)Format
A data frame with 3082 observations on the following 2 variables.
- DJIA
- Log-return of Dow Jones Industrial Average. 
- NASDAQ
- Log-return of NASDAQ. 
Details
This data set has been utilized in the source below and can be downloaded from the web-site of the Journal of Applied Econometrics (see link below).
Source
Van der Weide, Roy (2002), GO-GARCH: A Multivariate Generalized Orthogonal GARCH Model, Journal of Applied Econometrics, 17(5), 549 – 564.
References
http://qed.econ.queensu.ca/jae/2002-v17.5/van_der_weide/
See Also
Examples
data(VDW)
str(VDW)
Autocorrelations of a Matrix Process
Description
This function computes the autocorrelation matrix for a given lag. For instance, it is used for estimating GO-GARCH models whence the method of moments is utilized.
Usage
cora(SSI, lag = 1, standardize = TRUE)
Arguments
| SSI | Array with dimension  | 
| lag | Integer, the lag for which the autocorrelation is computed. | 
| standardize | Logical, if  | 
Details
This function computes the autocorrelation matrix according to:
    \hat{\Gamma}_k (s) = \frac{1}{n} \sum_{t = k + 1}^n S_t S_{t-k}
  
    \hat{\Phi}_k (s) = \hat{\Gamma}_0 (s)^{-1/2} \hat{\Gamma}_k (s)
    \hat{\Gamma}_0 (s)^{-1/2}
  
It is computationally assured that \hat{\Phi}_k (s) is symmetric
by setting it equal to: \hat{\Phi}_k (s) = \frac{1}{2}(\hat{\Phi}_k (s) +
  \hat{\Phi}_k (s)'). The standardization matrix \hat{\Gamma}_0
  (s)^{-1/2} is derived from the singular value decomposition of the
co-variance matrix at lag zero.   
Value
| cora | Matrix with dimension  | 
Author(s)
Bernhard Pfaff
References
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
See Also
Methods for Function goest
Description
These are methods for estimating GO-GARCH models. Currently only a method for estimating GO-GARCH models by Maximum-Likelihood is implemented.
Details
The declared estimation methods are called from function
gogarch.  
Methods
- goest
- signature(object = "Goestica")
- goest
- signature(object = "Goestmm")
- goest
- signature(object = "Goestml")
- goest
- signature(object = "Goestnls")
Author(s)
Bernhard Pfaff
See Also
garchFit, Goestica,
Goestml, Goestnls,
Goestmm, gogarch
Specification and estimation of GO-GARCH models
Description
This function steers the specification and estimation of GO-GARCH models.
Usage
gogarch(data, formula, scale = FALSE, estby = c("ica", "mm", "ml", "nls"),
  lag.max = 1, initial = NULL, garchlist = list(init.rec = "mci", delta
  = 2, skew = 1, shape = 4, cond.dist = "norm", include.mean = FALSE,
  include.delta = NULL, include.skew = NULL, include.shape = NULL,
  leverage = NULL, trace = FALSE, algorithm = "nlminb", hessian =
  "ropt", control = list(), title = NULL, description = NULL), ...) 
Arguments
| data | Matrix: the original data set. | 
| formula | Formula: valid formula for univariate GARCH models. | 
| scale | Logical, if  | 
| estby | Character: by fast ICA  | 
| initial | Numeric: starting values for optimization (used if
 | 
| lag.max | Integer: The number of used lags for computing the
matched orthogonal matrices  | 
| garchlist | List: Elements are passed to  | 
| ... | Ellipsis argument: is passed to the  | 
Details
The ellipsis argument is passed to the function fastICA if
estby = "ica" has been set, or to optim if estby
  = "nls" is employed or to nlminb if the GO-GARCH model is
estimated by maximum likelihood, i.e., estby = "ml". It
is not employed if the methods of moments estimator is chosen.
If the argument initial is left NULL, the starting
values are computed according seq(3.0, 0.1, length.out = l),
whereby l is the length of initial for estby =
  "ml" and are set to rep(0.1, d, whereby  for
method = "nls". This length must be equal to m * (m -
  1)/2 for estimation by Maximum-Likelihood and m * (m + 1)/2 for
estimation by non-linear least-Squares, whereby m is the number
of columns of data.   
Value
Dependent on the chosen estimation method either an object of class
Goestica or, Goestmm or Goestml or
Goestnls is returned. All of these classes extend the
GoGARCH class. 
Author(s)
Bernhard Pfaff
References
Van der Weide, Roy (2002), GO-GARCH: A Multivariate Generalized Orthogonal GARCH Model, Journal of Applied Econometrics, 17(5), 549 – 564.
Boswijk, H. Peter and van der Weide, Roy (2006), Wake me up before you GO-GARCH, Tinbergen Institute Discussion Paper, TI 2006-079/4, University of Amsterdam and Tinbergen Institute.
Boswijk, H. Peter and van der Weide, Roy (2009), Method of Moments Estimation of GO-GARCH Models, Working Paper, University of Amsterdam, Tinbergen Institute and World Bank.
Broda, S.A. and Paolella, M.S. (2008): CHICAGO: A Fast and Accurate Method for Portfolio Risk Calculation, Swiss Finance Institute, Research Paper Series No. 08-08, Zuerich.
See Also
GoGARCH, Goestica,
Goestmm, Goestnls,
Goestml, goest-methods
Examples
## Not run: 
library(vars)
## Boswijk / van der Weide (2009)
data(BVDWSTOXX)
BVDWSTOXX <- zoo(x = BVDWSTOXX[, -1], order.by = BVDWSTOXX[, 1])
BVDWSTOXX <- window(BVDWSTOXX, end = as.POSIXct("2007-12-31"))
BVDWSTOXX <- diff(log(BVDWSTOXX))
sectors <- BVDWSTOXX[, c("AutoParts", "Banks", "OilGas")]
sectors <- apply(sectors, 2, scale, scale = FALSE)
gogmm <- gogarch(sectors, formula = ~garch(1,1), estby = "mm",
         lag.max = 100)
gogmm
## Boswijk / van der Weide (2006)
data(BVDW)
BVDW <- zoo(x = BVDW[, -1], order.by = BVDW[, 1])
BVDW <- diff(log(BVDW)) * 100
gognls <- gogarch(BVDW, formula = ~garch(1,1), scale = TRUE,
          estby = "nls")
gognls
## van der Weide (2002)
data(VDW)
var1 <- VAR(scale(VDW), p = 1, type = "const")
resid <- residuals(var1)
gogml <- gogarch(resid, ~garch(1, 1), scale = TRUE,
         estby = "ml", control = list(iter.max = 1000))
gogml
solve(gogml@Z)
## End(Not run)
Constructor function for objects of class "Goinit"
Description
This function can be utilized to create objects of class
Goinit. These objects are the starting point for estimating
GO-GARCH models.
Usage
goinit(X, garchf = ~garch(1, 1), scale = FALSE)
Arguments
| X | Matrix: the data matrix. | 
| garchf | Formula: A formula object that will be used in the GARCH models of the uncorrelated components. | 
| scale | Logical, if  | 
Details
This function computes the variance/covariance matrix of
X. Next the singular value decomposition is applied and the
projection matrix as well as the diagonal matrix with the square roots
of the eigen values are computed.
Value
An object of class Goinit.
Author(s)
Bernhard Pfaff
See Also
Examples
## Not run: 
library(vars)
data(VDW)
var1 <- VAR(VDW, p = 1, type = "const")
resid <- resid(var1)
goinit(resid, scale = TRUE)
## End(Not run)
Log-Likelihood function of GO-GARCH models
Description
This function returns the negative of the log-Likelihood function for GO-GARCH models.
Usage
gollh(params, object, garchlist)
Arguments
| params | Vector of initial values for  | 
| object | An object of class  | 
| garchlist | List, elements are passed to  | 
Details
The log-Likelihood function of GO-GARCH models is given as:
    L_{\theta, \alpha, \beta} = - \frac{1}{2} \sum_{t=1}^T m \log(2\pi)
    + \log|Z_\theta Z_\theta '| + \log|H_t| + y' H_t^{-1}y_t
  
whereby Z = P \Delta^{\frac{1}{2}} U_0, y_t = Z^{-1}x_t and
H_t is the conditional variance matrix of the independent
components. 
Value
| negll | Scalar, the negative value of the log-Likelihood function. | 
Author(s)
Bernhard Pfaff
References
Van der Weide, Roy (2002), GO-GARCH: A Multivariate Generalized Orthogonal GARCH Model, Journal of Applied Econometrics, 17(5), 549 – 564.
See Also
Non-linear least-squares estimation of matrix B
Description
This is the target function for estimating the matrix B by
non-linear least-squares. It is used in the estimation method
goest if method = "nls" is chosen.
Usage
gonls(params, SSI)
Arguments
| params | The initial values of the  | 
| SSI | A list with two elements, each a list itself, containing
 | 
Details
Boswijk and van der Weiden (2006) proposed the following criterion function:
    S(A) = \frac{1}{n} \sum_{t = 1}^n tr([s_t s_t' - I_m - B(s_{t-1}
    s_{t-1}' - I_m)B]^2) = S^*(B)
  
for retrieving the matrix U. This matrix is the eigen vector
matrix of B. The linear map Z = P \Delta^{1/2} U and its
inverse can then be computed for calculating the component matrix
Y = X Z^{-1}.
Value
| f | 
 | 
Author(s)
Bernhard Pfaff
References
Boswijk, H. Peter and van der Weide, Roy (2006), Wake me up before you GO-GARCH, Tinbergen Institute Discussion Paper, TI 2006-079/4, University of Amsterdam and Tinbergen Institute.
See Also
Creates an object of class GoGARCH based on Euler angles
Description
This function returns an object of class GoGARCH based on an
input vector of Euler angles.
Usage
gotheta(theta, object, garchlist = list(init.rec = "mci", delta = 2,
skew = 1, shape = 4, cond.dist = "norm", include.mean = FALSE,
include.delta = NULL, include.skew = NULL, include.shape = NULL,
leverage = NULL, trace = FALSE, algorithm = "nlminb", hessian = "ropt",
control = list(), title = NULL, description = NULL))
Arguments
| theta | Vector of Euler angles. | 
| object | An object of formal class  | 
| garchlist | List with optional elements passed to  | 
Details
In a first step the orthogonal matrix U is computed as the
product of rotation matrices given the vector theta of Euler
angles with the function UprodR. The linear map Z is
computed next as Z = P D^{\frac{1}{2}} U'. The unobserved
components Y are calculated as Y = X Z^{-1}. These are
then utilized in the estimation of the univariate GARCH models
according to object@garchf. The conditional variance/covariance
matrices are calculated according to V_t = Z H_t Z' whereby
H_t signifies a matrix with the conditional variances of the
unvariate GARCH models on its diagonal.  
Value
Returns an object of class GoGARCH.
Author(s)
Bernhard Pfaff
References
Van der Weide, Roy (2002), GO-GARCH: A Multivariate Generalized Orthogonal GARCH Model, Journal of Applied Econometrics, 17(5), 549 – 564.
See Also
Goinit, GoGARCH,
Goestml, garchFit
Examples
## Not run: 
library(vars)
data(VDW)
var1 <- VAR(VDW, p = 1, type = "const")
resid <- resid(var1)
gin <- goinit(resid, scale = TRUE)
gotheta(0.5, gin)
## End(Not run)
Returns a symmetric matrix from a vector
Description
This function returns the symmetric matrix X from a vector that
resulted from v = vech(X).
Usage
unvech(v)
Arguments
| v | Vector, numeric. | 
Details
The vector v must have length equal to m * (m + 1) / 2,
whereby m is a dimension of the symmetric matrix X_{m
  \times m}. 
Value
| X | Matrix, symmetric of order  | 
Author(s)
Bernhard Pfaff
See Also
Examples
v <- c(1, 2, 3, 4, 5, 6)
unvech(v)
Validation function for objects of class Goinit
Description
This function validates objects of class Goinit.
Usage
validGoinitObject(object)
Arguments
| object | Object of class  | 
Details
This function is utilized by validObject(). It is tested
whether object@V, object@P, object@Dsqr are
square matrices; object@V coincides with the singular value
decomposition. 
Value
| TRUE | Logical,  | 
Author(s)
Bernhard Pfaff
See Also
Examples
data(VDW)
go <- goinit(VDW)
validObject(go)
Validation function for objects of class Orthom
Description
This function validates objects of class Orthom.
Usage
validOrthomObject(object)
Arguments
| object | Object of class  | 
Details
This function is utilized by validObject(). It is tested
whether object@M is a square matrix, has det(M) = 1 and
MM' = I. 
Value
| TRUE | Logical,  | 
Author(s)
Bernhard Pfaff
See Also
Examples
theta <- c(pi/3, pi/5, pi/7)
U <- UprodR(theta)
validObject(U)