rankhospital.R

rankhospital <- function(state, outcome, num = "best") {
    
    ## Reads outcome data
    file_data <- read.csv("outcome-of-care-measures.csv", sep = ",")
    
    ## Checks that state and outcome are valid
    valid_states <- c("AL", "AK", "AZ", "AR", "CA", "CO", "CT", "DE", "FL", "GA", "HI", "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN", "MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC", "ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", "TN", "TX", "UT", "VT", "VA", "WA", "WV", "WI", "WY")
    valid_outcomes <- c("heart attack", "heart failure", "pneumonia")
    if (!is.element(state, valid_states)) stop("invalid state")
    if (!is.element(outcome, valid_outcomes)) stop("invalid outcome")
    
    ## Returns hospital name in that state with lowest 30-day death
    data <- file_data[file_data$State == state,]
    header_name <- NULL
    if (outcome == "heart attack") header_name <- "Hospital.30.Day.Death..Mortality..Rates.from.Heart.Attack"
    else if (outcome == "heart failure") header_name <- "Hospital.30.Day.Death..Mortality..Rates.from.Heart.Failure"
    else header_name <- "Hospital.30.Day.Death..Mortality..Rates.from.Pneumonia"

    sorted_data <- data[order(as.numeric(as.character(data[,header_name])), as.character(data[,"Hospital.Name"])),]
    sorted_data <- sorted_data[!sorted_data[,header_name] == "Not Available",]
    if (num == "best") {
        return(best(state, outcome))
    } else if (num == "worst") {
        return(tail(as.character(sorted_data[,"Hospital.Name"]), n = 1))
    }
    return(as.character(sorted_data[,"Hospital.Name"][num]))
}