metainf <- function(x, pooled, sortvar) {
  
  
  ##
  ##
  ## (1) Check for meta object and upgrade older meta objects
  ##
  ##
  chkclass(x, "meta")
  x <- updateversion(x)
  ##
  k.all <- length(x$TE)
  if (k.all < 2) {
    warning("Nothing calculated (minimum number of studies: 2).")
    return(invisible(NULL))
  }
  
  
  ##
  ##
  ## (2) Check other arguments
  ##
  ##
  if (!missing(pooled))
    pooled <- setchar(pooled, c("fixed", "random"))
  else
    if (!x$comb.fixed & x$comb.random)
      pooled <- "random"
    else
      pooled <- "fixed"
  ##
  mf <- match.call()
  error <- try(sortvar <- eval(mf[[match("sortvar", names(mf))]],
                               as.data.frame(x, stringsAsFactors = FALSE),
                               enclos = sys.frame(sys.parent())),
               silent = TRUE)
  if (class(error) == "try-error") {
    xd <- x$data
    sortvar <- eval(mf[[match("sortvar", names(mf))]],
                    xd, enclos = NULL)
    if (!is.null(x$data$.subset))
      sortvar <- sortvar[x$data$.subset]
  }
  sort <- !is.null(sortvar)
  if (sort && (length(sortvar) != k.all))
    stop("Number of studies in object 'x' and argument 'sortvar' have different length.")
  if (!sort)
    sortvar <- 1:k.all
  
  
  ##
  ##
  ## (3) Sort variables
  ##
  ##
  o <- order(sortvar)
  ##
  n.e <- x$n.e[o]
  n.c <- x$n.c[o]
  n   <- x$n[o]
  ##
  event.e <- x$event.e[o]
  event.c <- x$event.c[o]
  event   <- x$event[o]
  ##
  mean.e <- x$mean.e[o]
  mean.c <- x$mean.c[o]
  ##
  sd.e <- x$sd.e[o]
  sd.c <- x$sd.c[o]
  ##
  time.e <- x$time.e[o]
  time.c <- x$time.c[o]
  time   <- x$time[o]
  ##
  cor <- x$cor[o]
  ##
  TE <- x$TE[o]
  seTE <- x$seTE[o]
  ##
  if (length(x$incr) > 1)
    incr <- x$incr[o]
  else if (!is.null(x$incr))
    incr <- rep_len(x$incr, k.all)
  else
    incr <- x$incr
  ##
  studlab <- x$studlab[o]
  slab <- c(paste("Omitting", studlab), "Pooled estimate")
  studlab <- c(rev(rev(slab)[-1]), " ", rev(slab)[1])
  
  
  ##
  ##
  ## (4) Do sensitivity analysis
  ##
  ##
  res.i <- matrix(NA, ncol = 12, nrow = k.all)
  ##
  for (i in 1:k.all) {
    sel <- -i
    ##
    if (length(incr) > 1)
      incr.i <- incr[sel]
    else
      incr.i <- incr
    ##
    if (inherits(x, "metabin"))
      m <- metabin(event.e[sel], n.e[sel], event.c[sel], n.c[sel],
                   ##
                   method = x$method, sm = x$sm,
                   incr = incr.i, allincr = x$allincr, addincr = x$addincr,
                   allstudies = x$allstudies, MH.exact = x$MH.exact,
                   RR.cochrane = x$RR.cochrane,
                   ##
                   level.comb = x$level.comb,
                   ##
                   hakn = x$hakn,
                   method.tau = x$method.tau,
                   tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                   ##
                   keepdata = FALSE,
                   warn = FALSE)
    ##
    if (inherits(x, "metacont"))
      m <- metacont(n.e[sel], mean.e[sel], sd.e[sel],
                    n.c[sel], mean.c[sel], sd.c[sel],
                    ##
                    sm = x$sm, pooledvar = x$pooledvar,
                    ##
                    level.comb = x$level.comb,
                    ##
                    hakn = x$hakn,
                    method.tau = x$method.tau,
                    tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                    ##
                    keepdata = FALSE,
                    warn = FALSE)
    ##
    if (inherits(x, "metacor"))
      m <- metacor(cor[sel], n[sel],
                   ##
                   sm = x$sm,
                   ##
                   level.comb = x$level.comb,
                   ##
                   hakn = x$hakn,
                   method.tau = x$method.tau,
                   tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                   ##
                   keepdata = FALSE)
    ##
    if (inherits(x, "metagen"))
      m <- metagen(TE[sel], seTE[sel],
                   ##
                   sm = x$sm,
                   ##
                   level.comb = x$level.comb,
                   ##
                   hakn = x$hakn,
                   method.tau = x$method.tau,
                   tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                   ##
                   keepdata = FALSE,
                   warn = FALSE)
    ##
    if (inherits(x,"metainc"))
      m <- metainc(event.e[sel], time.e[sel],
                   event.c[sel], time.c[sel],
                   ##
                   method = x$method,
                   sm = x$sm,
                   incr = incr.i, allincr = x$allincr, addincr = x$addincr,
                   ##
                   level.comb = x$level.comb,
                   ##
                   hakn = x$hakn, method.tau = x$method.tau,
                   tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                   ##
                   keepdata = FALSE,
                   warn = FALSE)
    ##
    if (inherits(x, "metaprop"))
      m <- metaprop(event[sel], n[sel],
                    ##
                    sm = x$sm,
                    incr = incr.i, allincr = x$allincr, addincr = x$addincr,
                    method.ci = x$method.ci,
                    ##
                    level.comb = x$level.comb,
                    ##
                    hakn = x$hakn,
                    method.tau = x$method.tau,
                    tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                    ##
                    keepdata = FALSE,
                    warn = FALSE)
    ##
    if (inherits(x, "metarate"))
      m <- metarate(event[sel], time[sel],
                    ##
                    sm = x$sm,
                    incr = incr.i, allincr = x$allincr, addincr = x$addincr,
                    ##
                    level.comb = x$level.comb,
                    ##
                    hakn = x$hakn,
                    method.tau = x$method.tau,
                    tau.preset = x$tau.preset, TE.tau = x$TE.tau,
                    ##
                    keepdata = FALSE,
                    warn = FALSE)
    ##
    sel.pft <- inherits(x, "metaprop") & x$sm == "PFT"
    sel.irft <- inherits(x, "metarate") & x$sm == "IRFT"
    ##
    if (pooled == "fixed") {
      res.i[i,] <- c(m$TE.fixed,                                    #  1
                     m$seTE.fixed,                                  #  2
                     m$lower.fixed,                                 #  3
                     m$upper.fixed,                                 #  4
                     m$pval.fixed,                                  #  5
                     m$I2,                                          #  6
                     m$tau,                                         #  7
                     sum(m$w.fixed, na.rm = TRUE),                  #  8
                     if (sel.pft) 1 / mean(1 / n[sel]) else NA,     #  9
                     NA,                                            # 10
                     if (sel.irft) 1 / mean(1 / time[sel]) else NA, # 11
                     m$Rb                                           # 12
                     )
    }
    ##
    else if (pooled == "random") {
      res.i[i,] <- c(m$TE.random,                                   #  1
                     m$seTE.random,                                 #  2
                     m$lower.random,                                #  3
                     m$upper.random,                                #  4
                     m$pval.random,                                 #  5
                     m$I2,                                          #  6
                     m$tau,                                         #  7
                     sum(m$w.random, na.rm = TRUE),                 #  8
                     if (sel.pft) 1 / mean(1 / n[sel]) else NA,     #  9
                     if (x$hakn) m$df.hakn else NA,                 # 10
                     if (sel.irft) 1 / mean(1 / time[sel]) else NA, # 11
                     m$Rb                                           # 12
                     )
    }
  }
  ##
  TE.i <- res.i[, 1]
  seTE.i <- res.i[, 2]
  lower.i <- res.i[, 3]
  upper.i <- res.i[, 4]
  pval.i <- res.i[, 5]
  I2.i <- res.i[, 6]
  tau.i <- res.i[, 7]
  weight.i <- res.i[, 8]
  n.harmonic.mean.i <- res.i[, 9]
  if (pooled == "random" & x$hakn)
    df.hakn.i <- res.i[, 10]
  t.harmonic.mean.i <- res.i[, 11]
  Rb.i <- res.i[, 12]
  ##  
  if (pooled == "fixed") {
    TE.s <- x$TE.fixed
    seTE.s <- x$seTE.fixed
    TE.s.lower <- x$lower.fixed
    TE.s.upper <- x$upper.fixed
    pval.s <- x$pval.fixed
    w.s <- sum(x$w.fixed, na.rm = TRUE)
  }
  ##
  else if (pooled == "random") {
    TE.s <- x$TE.random
    seTE.s <- x$seTE.random
    TE.s.lower <- x$lower.random
    TE.s.upper <- x$upper.random
    pval.s <- x$pval.random
    w.s <- sum(x$w.random, na.rm = TRUE)
  }
  
  
  ##
  ##
  ## (5) Generate R object
  ##
  ##
  res <- list(TE = c(TE.i, NA, TE.s),
              seTE = c(seTE.i, NA, seTE.s),
              lower = c(lower.i, NA, TE.s.lower),
              upper = c(upper.i, NA, TE.s.upper),
              studlab = studlab,
              p.value = c(pval.i, NA, pval.s),
              w = c(weight.i, NA, w.s),
              I2 = c(I2.i, NA, x$I2),
              Rb = c(Rb.i, NA, x$Rb),
              tau = c(tau.i, NA, x$tau),
              df.hakn = if (pooled == "random" & x$hakn) c(df.hakn.i, NA, x$df.hakn) else NULL,
              sm = x$sm, method = x$method, k = x$k,
              pooled = pooled,
              comb.fixed = ifelse(pooled == "fixed", TRUE, FALSE),
              comb.random = ifelse(pooled == "random", TRUE, FALSE),
              TE.fixed = NA, seTE.fixed = NA,
              TE.random = NA, seTE.random = NA,
              Q = NA,
              level.comb = x$level.comb,
              hakn = x$hakn,
              method.tau = x$method.tau,
              tau.preset = x$tau.preset,
              TE.tau = x$TE.tau,
              n.harmonic.mean = c(n.harmonic.mean.i, NA, 1 / mean(1 / n)),
              t.harmonic.mean = c(t.harmonic.mean.i, NA, 1 / mean(1 / time)),
              prediction = FALSE,
              ##
              backtransf = x$backtransf,
              pscale = x$pscale,
              irscale = x$irscale, irunit = x$irunit,
              title = x$title, complab = x$complab,
              outclab = x$outclab,
              ##
              call = match.call())
  
  res$version <- packageDescription("meta")$Version
  
  class(res) <- c("metainf", "meta")
  if (inherits(x, "trimfill"))
    class(res) <- c(class(res), "trimfill")
  
  res
}