R/qhermite.R

In hermite: Generalized Hermite Distribution

qhermite <- function(p, a, b, m=2, lower.tail=TRUE)
{
  if (a < 0 | b < 0 | floor(m)!=m | m < 2)
  {
    warning("improper parameter specification")
    return(NaN)
  }
  q <- vector()
  j <- 1
  if (lower.tail == FALSE) p <- 1-p
  if (a < 20 & b < 20)
  {
    while(!is.na(p[j]))
    {
      f <- 0
      q[j] <- -1
      if ((p[j] > 1 | p[j] < 0))
      {
        warning("NaNs produced")
        q[j] <- NaN
      }
      if (p[j] == 1)
      {
        q[j] <- Inf
      } else {
        if(p[j] < 1)
        {
          while(f<p[j])
          {
            q[j] <- q[j] + 1
            f <- dhermite(q[j],a,b,m) + f
          }
        }
      }
      j <- j + 1
    }
  }
  if (a > 20 | b > 20)
  {
    while(!is.na(p[j]))
    {
      if ((p[j] > 1 | p[j] < 0))
      {
        warning("NaNs produced")
        q[j] <- NaN
      } else {
        q[j] <- ifelse(p[j] != 1, floor(cofi(p[j], a, b, m)) + 1, Inf)
      }
      j <- j + 1
    }
  }
  q <- ifelse(is.nan(q) | q>=0, q, 0)
  return(q)
}