rankall.R

rankall <- function(outcome, num = "best") {
  ## Read the outcome data
  dat <- read.csv("outcome-of-care-measures.csv", colClasses = "character")
  ## Check that state and outcome are valid
  states = unique(dat[, 7])
  switch(outcome, `heart attack` = {
    col = 11
  }, `heart failure` = {
    col = 17
  }, pneumonia = {
    col = 23
  }, stop("invalid outcome"))
  
  ## Return hospital name in that state with the given rank 30-day death rate
  dat[, col] = as.numeric(dat[, col])
  dat = dat[, c(2, 7, col)]  # leave only name, state, and death rate
  dat = na.omit(dat)
  # head(dat) Hospital.Name State 1 SOUTHEAST ALABAMA MEDICAL CENTER AL 2
  # MARSHALL MEDICAL CENTER SOUTH AL 3 ELIZA COFFEE MEMORIAL HOSPITAL AL 7 ST
  # VINCENT'S EAST AL 8 DEKALB REGIONAL MEDICAL CENTER AL 9 SHELBY BAPTIST
  # MEDICAL CENTER AL
  # Hospital.30.Day.Death..Mortality..Rates.from.Heart.Attack 1 14.3 2 18.5 3
  # 18.1 7 17.7 8 18.0 9 15.9
  rank_in_state <- function(state) {
    df = dat[dat[, 2] == state, ]
    nhospital = nrow(df)
    switch(num, best = {
      num = 1
    }, worst = {
      num = nhospital
    })
    if (num > nhospital) {
      result = NA
    }
    o = order(df[, 3], df[, 1])
    result = df[o, ][num, 1]
    c(result, state)
  }
  output = do.call(rbind, lapply(states, rank_in_state))
  output = output[order(output[, 2]), ]
  rownames(output) = output[, 2]
  colnames(output) = c("hospital", "state")
  data.frame(output)
}