R/fmmcSemiParam_with_cor.R

Defines functions fmmcSemiParam_with_cor

fmmcSemiParam_with_cor = function (B = 1000, factor.ret, beta, alpha, resid.par, resids, resid.dist = c("normal",
                                                                       "Cornish-Fisher", "skew-t"), boot.method = c("random", "block"),
          seed = 123)
{
  if (missing(factor.ret)) {
    stop("Missing argument: factor.ret")
  }
  else {
    factor.ret <- na.omit(as.matrix(factor.ret))
    factor.names <- colnames(factor.ret)
    K = ncol(factor.ret)
    T = nrow(factor.ret)
  }
  if (missing(beta)) {
    stop("Missing argument: beta")
  }
  else {
    fund.names <- rownames(beta)
    N = nrow(beta)
    if (all(colnames(beta) != factor.names) || ncol(beta) !=
        length(factor.names)) {
      stop("Invalid argument: beta and factor.ret should correspond to the same \n           set of factors")
    }
  }
  resid.dist = resid.dist[1]
  switch(resid.dist, normal = {
    if (ncol(resid.par) != 1) {
      stop("Invalid argument: resid.par")
    }
  }, `Cornish-Fisher` = {
    if (ncol(resid.par) != 3) {
      stop("Invalid argument: resid.par")
    }
  }, `skew-t` = {
    if (ncol(resid.par) != 4) {
      stop("Invalid argument: resid.par")
    }
  }, stop("Invalid argument: resid.dist must be 'normal', 'Cornish-Fisher' or 'skew-t'"))
  boot.method = boot.method[1]
  if (!(boot.method %in% c("random", "block"))) {
    stop("Invalid argument: boot.method must be either 'random' or 'block'")
  }
  if (missing(alpha)) {
    alpha <- matrix(0, nrow(beta))
    rownames(alpha) = fund.names
  }
  if ((nrow(beta) != nrow(alpha)) || (nrow(beta) != nrow(resid.par))) {
    stop("Invalid argument: alpha, beta and resid.par should have the same \n         number of funds")
  }
  set.seed(seed)
  if (boot.method == "random") {
    boot.idx <- sample(x = T, size = B, replace = TRUE)
  }
  else {
    boot.idx <- as.vector(tseries::tsbootstrap(x = 1:T, nb = ceiling(B/T),
                                      type = "stationary"))
    adj.B <- ceiling(B/T) * T - B
    if (adj.B > 0) {
      boot.idx <- boot.idx[1:B]
    }
  }
  boot.factor.ret <- factor.ret[boot.idx, ]
  switch(resid.dist, normal = {
    sig = cov(resids, use = "p")
    #sim.resid[, i] <- rnorm(n = B, mean = 0, sd = resid.par[i, ])
    sim.resid = mvtnorm::rmvnorm(n=B, sigma = sig)
    colnames(sim.resid) = fund.names
  }, `Cornish-Fisher` = {
    sim.resid <- matrix(0, B, N)
    colnames(sim.resid) = fund.names
    for(i in fund.names){
      sim.resid[, i] <- rCornishFisher(n = B, dp = resid.par[i,
                                                             ])
    }

  }, `skew-t` = {
    sig = cov(resids, use = "p")
    #sim.resid[, i] <- rst(n = B, dp = resid.par[i, ])
    sim.resid = mvtnorm::rmvt(n=B, sigma = sig)
    colnames(sim.resid) = fund.names
  })
  sim.fund.ret = sapply(1:nrow(alpha), FUN = function(i)rep(alpha[i, 1], B)) + (boot.factor.ret %*% t(beta)) + sim.resid
  #noAlpha = (boot.factor.ret %*% t(beta)) + sim.resid


  # sim.fund.ret <- matrix(0, B, N)
  # #sim.resid <- matrix(0, B, N)
  # colnames(sim.fund.ret) = colnames(sim.resid) = fund.names
  # for (i in fund.names) {
  #   switch(resid.dist, normal = {
  #     sig = cov(resids, use = "p")
  #     #sim.resid[, i] <- rnorm(n = B, mean = 0, sd = resid.par[i, ])
  #     sim.resid = mvtnorm::rmvnorm(n=B, sigma = sig)
  #   }, `Cornish-Fisher` = {
  #     sim.resid[, i] <- rCornishFisher(n = B, dp = resid.par[i,
  #                                                            ])
  #   }, `skew-t` = {
  #     sig = cov(resids, use = "p")
  #     #sim.resid[, i] <- rst(n = B, dp = resid.par[i, ])
  #     sim.resid = mvtnorm::rmvt(n=B, sigma = sig)
  #   })
  #   sim.fund.ret[, i] = alpha[i, 1] + boot.factor.ret %*%
  #     t(beta[i, , drop = FALSE]) + sim.resid[, i]
  # }
  result <- list(sim.fund.ret = sim.fund.ret, boot.factor.ret = boot.factor.ret,
                 sim.resid = sim.resid)
  return(result)
}
bplloyd/Core documentation built on May 11, 2017, 2:39 p.m.