RVineLogLik(VineCopula)
RVineLogLik()所属R语言包:VineCopula
Log-likelihood of an R-vine copula model
R-藤Copula模型的对数似然
译者:生物统计家园网 机器人LoveR
描述----------Description----------
This function calculates the log-likelihood of a d-dimensional R-vine copula model for a given copula data set.
此功能对于一个给定的Copula函数数据集的一个d维的R-藤copula模型计算对数似然。
用法----------Usage----------
RVineLogLik(data, RVM, par=RVM$par, par2=RVM$par2, separate=FALSE)
参数----------Arguments----------
参数:data
An N x d data matrix (with uniform margins).
一个N×d数据矩阵(均匀的利润)。
参数:RVM
An RVineMatrix object including the structure and the pair-copula families and parameters.
RVineMatrix对象的结构和对Copula的家庭,和参数。
参数:par
A d x d matrix with the pair-copula parameters (optional; default: par = RVM$par).
DXD一个矩阵,对Copula函数的参数(可选,默认:par = RVM$par)。
参数:par2
A d x d matrix with the second parameters of pair-copula families with two parameters (optional; default: par2 = RVM$par2).
一个DXD矩阵的对Copula的家庭的第二个参数有两个参数(可选;默认:par2 = RVM$par2“)。
参数:separate
Logical; whether log-likelihoods are returned pointwisely (default: separate = FALSE).
逻辑;数似然性是否会返回取点(默认:separate = FALSE)。
Details
详细信息----------Details----------
For observations \boldsymbol{u}=(\boldsymbol{u}_1^\prime,...,\boldsymbol{u}_N^\prime)^\prime the log-likelihood of a d-dimensional R-vine copula with d-1 trees and corresponding edge sets E_1,...,E_{d-1} is given by
的观测\boldsymbol{u}=(\boldsymbol{u}_1^\prime,...,\boldsymbol{u}_N^\prime)^\prime的R-d维藤Copula的d-1树木和相应的边缘设置的对数似然E_1,...,E_{d-1}是由
where \boldsymbol{u}_i=(u_{i,1},...,u_{i,d})^\prime\in[0,1]^d,\ i=1,...,N. Further c_{j(e),k(e)|D(e)} denotes a bivariate copula density associated to an edge e and with parameter(s) \boldsymbol{θ}_{j(e),k(e)|D(e)}. Conditional distribution functions such as F(u_{i,j(e)}|\boldsymbol{u}_{i,D(e)}) are obtained recursively using the relationship
\boldsymbol{u}_i=(u_{i,1},...,u_{i,d})^\prime\in[0,1]^d,\ i=1,...,N。进一步c_{j(e),k(e)|D(e)}表示一个二元Copula的密度相关联的边缘e与参数(s)\boldsymbol{θ}_{j(e),k(e)|D(e)}。条件分布函数如F(u_{i,j(e)}|\boldsymbol{u}_{i,D(e)})递归使用的关系
where C_{uv_j|\boldsymbol{v}_{-j}} is a bivariate copula distribution function with parameter(s) θ and \boldsymbol{v}_{-j} denotes a vector with the j-th component v_j removed. The notation of h-functions is introduced for convenience. For more details see Dissmann et al. (2011).
C_{uv_j|\boldsymbol{v}_{-j}}是一个二元Copula函数的分布函数参数(S)θ和\boldsymbol{v}_{-j}表示向量个j组件v_j删除。为方便起见,引入的h-函数的符号。有关详细信息,请参阅Dissmann等。 (2011年)。
值----------Value----------
参数:loglik
The calculated log-likelihood value of the R-vine copula model.
所计算出的对数似然值的R-藤copula模型。
参数:V
The stored transformations (h-functions and log-likelihoods of each pair-copula) which may be used for posterior updates (three matrices: direct, indirect and value).
存储的变换式(h-函数和对数似然性的每对系词)可被用于后更新(三个矩阵:direct,indirect和value)。
(作者)----------Author(s)----------
Ulf Schepsmeier, Jeffrey Dissmann, Jakob Stoeber
参考文献----------References----------
Selecting and estimating regular vine copulae and application to financial returns. Submitted for publication. http://mediatum.ub.tum.de/node?id=1079277
参见----------See Also----------
BiCopHfunc, RVineMatrix, RVineMLE, RVineAIC, RVineBIC
BiCopHfunc,RVineMatrix,RVineMLE,RVineAIC,RVineBIC
实例----------Examples----------
# define 5-dimensional R-vine tree structure matrix[定义5维的R-葡萄树结构矩阵]
Matrix = c(5,2,3,1,4,0,2,3,4,1,0,0,3,4,1,0,0,0,4,1,0,0,0,0,1)
Matrix = matrix(Matrix,5,5)
# define R-vine pair-copula family matrix[定义R-藤对Copula的家庭矩阵]
family = c(0,1,3,4,4,0,0,3,4,1,0,0,0,4,1,0,0,0,0,3,0,0,0,0,0)
family = matrix(family,5,5)
# define R-vine pair-copula parameter matrix[定义R-藤对Copula函数的参数矩阵]
par = c(0,0.2,0.9,1.5,3.9,0,0,1.1,1.6,0.9,0,0,0,1.9,0.5,
0,0,0,0,4.8,0,0,0,0,0)
par = matrix(par,5,5)
# define second R-vine pair-copula parameter matrix[定义第二个R-藤对Copula函数的参数矩阵]
par2 = matrix(0,5,5)
# define RVineMatrix object[定义RVineMatrix对象]
RVM = RVineMatrix(Matrix=Matrix,family=family,par=par,par2=par2,
names=c("V1","V2","V3","V4","V5"))
# simulate a sample of size 300 from the R-vine copula model[从R-藤copula模型,模拟样品的尺寸为300]
simdata = RVineSim(300,RVM)
# compute the log-likelihood[计算对数似然]
ll = RVineLogLik(simdata,RVM,separate=FALSE)
ll$loglik
# compute the pointwise log-likelihoods[计算逐点对数似然度]
ll = RVineLogLik(simdata,RVM,separate=TRUE)
ll$loglik
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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