#example from s-plus:
module("finmetrics")
mod = garch(hp.s~1, ~garch(1,1),cond.dist="gaussian")
summary(mod)
#Estimated Coefficients:
#-------------------------------------------------
# Value Std.Error t value Pr(>|t|)
# C 0.00046317 4.646e-004 0.9969 3.189e-001
# A 0.00005141 8.978e-006 5.7255 1.188e-008
# ARCH(1) 0.10000000 8.115e-003 12.3228 0.000e+000
#GARCH(1) 0.80000000 2.172e-002 36.8356 0.000e+000
#if we obtain the hessian matrix then
#we can compute the Standard Errors
hessian=mod$cov$B
#observed Fisher information matrix=invert the Hessian
oi=solve( hessian)
se<-sqrt(diag(oi)) #Std.Error
se
#[1] 4.646089e-004 8.978495e-006 8.115018e-003 2.171813e-002
tvalue=as.vector(mod$coe/se) #t value
tvalue
#[1] 0.9968967 5.7255181 12.3228314 36.8355882
pvalue=(1-pnorm(abs(tvalue)))*2 #p value
pvalue
#[1] 3.188147e-001 1.031186e-008 0.000000e+000 0.000000e+000