R/calcIBCommission.R

In tmk-c/myrlib: My R library for daily work

#' Calculate IB's stock order commission.
#'
#' @param qty Order quantity.
#' @param price Entry price.
#'
#' @return IB's commission.
#' @export
calcIBCommission <- function(qty, price) {

  # Shares * 0.005 (min $1, max 1% of trade value)
  comm_lot <- -0.005
  comm_min <- -1
  comm_max <- qty * price * -0.01

  comm <- qty * comm_lot
  comm <- ifelse(comm > comm_min, comm_min,
          ifelse(comm < comm_max, comm_max, comm))
  comm <- round(comm, 2)

  return(comm)
}