bootstrap <var >标签有什么用
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解决时间 2021-03-19 21:05
- 提问者网友:爱了却不能说
- 2021-03-19 07:06
bootstrap <var >标签有什么用
最佳答案
- 五星知识达人网友:纵马山川剑自提
- 2021-03-19 07:55
全局样式 1 Bootstrap 中用到一些 HTML元素和CSS属性需要将页面设置为 HTML5 文档类型,即在页面顶部添加“
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- 1楼网友:人间朝暮
- 2021-03-19 08:17
"garchm" <- function(rtn,type=1){
# estimation of a gaussian garch(1,1)-m model.
##### the program uses garch(1,1) results as initial values.
# rtn: return series
# type = 1 for variance-in-mean
# = 2 for volatility-in-mean
# = 3 for log(variance)-in-mean
#
if(is.matrix(rtn))rtn=c(rtn[,1])
garchmdata <<- rtn
# obtain initial estimates
m1=garch11fit(garchmdata)
est=as.numeric(m1separ);ht=m1coefficients[1])
gam=as.numeric(m2coefficients[2])
params=c(mu=cnst,gamma=gam, omega=cc, alpha=ar,beta=ma)
lowbounds=c(mu=mean-4*semean,gamma=-10*abs(gam), omega=cc-2*secc, alpha=s, beta=ma-2*sema)
uppbounds=c(mu=mean+4*semean,gamma=10*abs(gam), omega=cc+2*secc ,alpha=ar+2*sear,beta=1-s)
vtmp <<- c(type,v1[1])
#
fit=nlminb(start = params, objective= glkm, lower=lowbounds, upper=uppbounds,
control=list(trace=3,rel.tol=1e-5))
epsilon = 0.0001 * fitpar
npar=length(params)
hessian = matrix(0, ncol = npar, nrow = npar)
for (i in 1:npar) {
for (j in 1:npar) {
x1 = x2 = x3 = x4 = fitpar
x1[i] = x1[i] + epsilon[i]; x1[j] = x1[j] + epsilon[j]
x2[i] = x2[i] + epsilon[i]; x2[j] = x2[j] - epsilon[j]
x3[i] = x3[i] - epsilon[i]; x3[j] = x3[j] + epsilon[j]
x4[i] = x4[i] - epsilon[i]; x4[j] = x4[j] - epsilon[j]
hessian[i, j] = (glkm(x1)-glkm(x2)-glkm(x3)+glkm(x4))/
(4*epsilon[i]*epsilon[j])
}
}
cat("maximized log-likehood: ",glkm(fitpar),"\n")
# step 6: create and print summary report:
se.coef = sqrt(diag(solve(hessian)))
tval = fitpar, se.coef, tval, 2*(1-pnorm(abs(tval))))
dimnames(matcoef) = list(names(tval), c(" estimate",
" std. error", " t value", "pr(>|t|)"))
cat("\ncoefficient(s):\n")
printcoefmat(matcoef, digits = 6, signif.stars = true)
m3=resivol(fitresiduals,sigma.t=m3sigma.t)
}
glkm = function(pars){
rtn <- garchmdata
mu=pars[1]; gamma=pars[2]; omega=pars[3]; alpha=pars[4]; beta=pars[5]
type=vtmp[1]
t=length(rtn)
# use conditional variance
if(type==1){
ht=vtmp[2]
et=rtn[1]-mu-gamma*ht
at=c(et)
for (i in 2:t){
sig2t=omega+alpha*at[i-1]^2+beta*ht[i-1]
ept = rtn[i]-mu-gamma**sig2t
at=c(at,ept)
ht=c(ht,sig2t)
}
}
# use volatility
if(type==2){
ht=vtmp[2]^2
et=rtn[1]-mu-gamma*vtmp[2]
at=c(et)
for (i in 2:t){
sig2t=omega+alpha*at[i-1]^2+beta*ht[i-1]
ept=rtn[i]-mu-gamma*sqrt(sig2t)
at=c(at,ept)
ht=c(ht,sig2t)
}
}
# use log(variance)
if(type==3){
ht=exp(vtmp[2])
et=rtn[1]-mu-gamma*vtmp[2]
at=c(et)
for (i in 2:t){
sig2t=omega+alpha*at[i-1]+beta*ht[i-1]
ept=rtn[i]-mu-gamma*log(abs(sig2t))
at=c(at,ept)
ht=c(ht,sig2t)
}
}
#
hh=sqrt(abs(ht))
glk=-sum(log(dnorm(x=at/hh)/hh))
glk
}
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