[R] microbenchmark relative summary

mbm_rel.R

mbm_rel <- function(x, d, relname = NULL, relpos = 1, inverse = FALSE, reltime = TRUE, unit){
  ## produces relative summaries from microbenchmark output ================
## ---- arguments ----------------------------------------------------------
  ## x a microbenchmark output object with two or more methods
  ## d number of rows to consider (in the order of rows of x)
  ## relname is name of metod for relative results
  ## relpos is the position of target metod for relative results relmethod/othermethod
  ## inverse = TRUE compute othermethods/relmethod or viceversa
  ## reltime, if true prints the time taken by the method, otherwise sets its values to 1
  ## unit can be “ns”, “us”, “ms”, “s”, “t”, “hz”, “khz”, “mhz”, “eps”, “f”
  ## default unit same as object. see microbenchmark documentation 
  ## -- author Giovanni Merola lsspaca@gmail.com ============================
  require(microbenchmark)
  if (missing(unit)){
    p <- summary(x)
    unit <- attr(p, "unit")
  }
  else 
    if(unit != "m"){
      p <- summary(x, unit = unit)
      unit <- attr(p, "unit")
    }
  else{
    p <- summary(x, unit = "s")
    p[,2:7] <- p[,2:7]/60
    unit <- "minutes"
  }
  
  ## moves rel method on top
  if (!is.null(relname))
    indt <- which(p$expr == relname)
  else
    indt <- relpos
  if (indt > 1)
    p <- p[ c(indt, (1:nrow(p))[-indt]), ]

  n <- p$neval
  rown <- as.character(p$expr)
  p <- p[,-1]
  first <- p[1, ]
  p <-   as.matrix(p)
  if (missing(d))
    d <- nrow(p)
  else
    if(d > nrow(p))
      stop(paste("too many methods required, only", nrow(p), "available"))
    else
      p <- p[1:d, ]
  p[2:d, ] <- t(t(p[2:d, ])/p[1, ])
  if (reltime == FALSE)
    p[1, 1:6] <- 1
  rownames(p) <- rep(NA, d)
  if (inverse == FALSE){
    p[ 2:d, 1:6]<- 1/p[ 2:d, 1:6]
    rownames(p)[2:d] <- paste0(rown[1], "/", rown[2:d])
  }
  else
    rownames(p)[2:d] <- paste0(rown[2:d], "/", rown[1])
  
  if (reltime == TRUE)
    rownames(p)[1] <- paste(rown[1], "time")  
  else
    rownames(p)[1] <- rown[1]
  p <- round(p , 3) 
  p[,7] <- n[1:d]
  p <- as.data.frame(p)
  attr(p, "unit") <- unit
  cat("Unit: ", unit, "\n", sep = "")
  return(p)
}