求助大神，在使用spdep包和spatialreg包时，想利用do_ldet函数，具体如何使用没问题。现在我想查看do_ldet函数使用的具体方法（如下面do_ldet函数源码中加粗函数），但所有加粗函数都找不到帮助文档。既然没有帮助文档，也找不到关于这些函数的任何信息，那do_ldet函数是如何使用这些函数的呢？能否认为R中就不存在这些加粗函数？或者应该从哪里找这些函数呢？

备注：
每一个加粗函数都是一种计算雅各比行列式的方法

【代码】：
library(spdep)
library(spatialreg)
do_ldet       #查看do_ldet函数时显示的函数源码

【do_ldet函数源码】
function (coef, env, which = 1)
{
    .Deprecated("spatialreg::do_ldet", msg = "Function do_ldet moved to the spatialreg package")
    if (requireNamespace("spatialreg", quietly = TRUE)) {
        return(spatialreg::do_ldet(coef = coef, env = env, which = which))
    }
    warning("install the spatialreg package")
    method <- get("method", envir = env)
    if (get("family", envir = env) == "SMA") {
        ldet <- eigen_sma_ldet(coef, env, which = which)
    }
    else {
        switch(method, eigen = {
            ldet <- eigen_ldet(coef, env, which = which)
        }, spam = {
            ldet <- spam_ldet(coef, env, which = which)
        }, spam_update = {
            ldet <- spam_update_ldet(coef, env, which = which)
        }, Matrix = {
            ldet <- Matrix_ldet(coef, env, which = which)
        }, Matrix_J = {
            ldet <- Matrix_J_ldet(coef, env, which = which)
        }, Chebyshev = {
            ldet <- cheb_ldet(coef, env, which = which)
        }, MC = {
            ldet <- mcdet_ldet(coef, env, which = which)
        }, LU = {
            ldet <- LU_ldet(coef, env, which = which)
        }, LU_prepermutate = {
            ldet <- LU_prepermutate_ldet(coef, env, which = which)
        }, moments = {
            ldet <- moments_ldet(coef, env, which = which)
        }, SE_classic = {
            ldet <- SE_classic_ldet(coef, env, which = which)
        }, SE_whichMin = {
            ldet <- SE_whichMin_ldet(coef, env, which = which)
        }, SE_interp = {
            ldet <- SE_interp_ldet(coef, env, which = which)
        }, stop("...\n\nUnknown method\n"))
    }
    ldet
}
<bytecode: 0x000000001ac00180>
<environment: namespace:spdep>