请看mle.tools
包。例如,在正态分布中,
library(mle.tools)
## Normal distribution
pdf <- quote(1 / (sqrt(2 * pi) * sigma) * exp(-0.5 / sigma ^ 2 * (x - mu) ^ 2))
lpdf <- quote(-log(sigma) - 0.5 / sigma ^ 2 * (x - mu) ^ 2)
x <- rnorm(n = 100, mean = 0.0, sd = 1.0)
expected.varcov(density = pdf, logdensity = lpdf, n = length(x), parms = c("mu", "sigma"),
mle = c(mean(x), sd(x)), lower = '-Inf', upper = 'Inf')
$mle
mu sigma
-0.01889498 0.96256386
$varcov
mu sigma
mu 9.265292e-03 -6.989460e-13
sigma -6.989460e-13 4.632646e-03
##Normal distribution
lpdf <- quote(-log(sigma) - 0.5 / sigma ^ 2 * (x - mu) ^ 2)
x <- rnorm(n = 100, mean = 0.0, sd = 1.0)
observed.varcov(logdensity = lpdf, X = x, parms = c("mu", "sigma"),
mle = c(mean(x), sd(x)))
$mle
mu sigma
0.02476464 1.12332365
$varcov
mu sigma
mu 1.261856e-02 2.617048e-19
sigma 2.617048e-19 6.405360e-03
更多详细信息,请参见mle.tools.pdf
。
g
未给出,pi
也未给出等等。如果您想要海森矩阵,在假定了g
之后,您将需要通过EM估计pi
向量,然后可以使用mle.tools
包来计算I。 - Onyambu