R/convert_odds.R

In papagorgio23/bettoR: Sports Betting Tools

#' @title Odds converter
#'
#' @description This function converts any odds or probability.
#'
#' @param odds Odds, or lines, for a given bet(s) (-115, -105)
#' @param input Type of odds for the input. Possible values are:
#' * `us`, American Odds
#' * `dec`, Decimal Odds
#' * `frac`, Fractional Odds
#' @param output Type of odds for the output. Possible values are:
#' * `all`, Returns all Odds
#' * `us`, American Odds
#' * `dec`, Decimal Odds
#' * `frac`, Fractional Odds
#' * `prob`, Implied Probability
#'
#' @return odds
#'
#' @examples convert_odds(c(-110, -110))
#' @examples convert_odds(
#'   odds = c(1.1, 2.1, 13, 6.5, 1.909),
#'   input = "dec",
#'   output = "us"
#' )
#' @examples convert_odds(
#'   odds = c(1/10, 11/10, 12/1, 11/2, 10/11),
#'   input = "frac",
#'   output = "all"
#' )
#'
#' @export
convert_odds <- function(odds,
                         input = "us",
                         output = "all") {
  ## Error handling
  if (!is.numeric(odds)) {
    stop("Odds must be numeric")
  }
  if (!input %in% c("us", "frac", "dec", "prob")) {
    stop("Input must be either: ('us', 'dec', 'frac', or 'prob')")
  }
  if (!output %in% c("all", "us", "frac", "dec", "prob")) {
    stop("Output must be either: ('all', 'us', 'dec', 'frac', or 'prob')")
  }
  ## American Odds
  if (input == "us") {
    if (output == "all") {
      dec <- odds
      dec[] <- NA_real_
      dec[which(odds <= -100)] <-
        -100 / odds[which(odds <= -100)] + 1
      dec[which(odds >= 100)] <- odds[which(odds >= 100)] / 100 + 1

      frac <- dec - 1
      frac <- MASS::fractions(frac)

      new_odds <- data.frame(
        Decimal = dec,
        American = odds,
        Fraction = as.character(frac),
        Implied_Probability = implied_prob(odds = odds, type = "us")
      )
    }
    if (output == "dec") {
      new_odds <- odds
      new_odds[] <- NA_real_
      new_odds[which(odds <= -100)] <-
        -100 / odds[which(odds <= -100)] + 1
      new_odds[which(odds >= 100)] <-
        odds[which(odds >= 100)] / 100 + 1
    }
    if (output == "frac") {
      new_odds <- odds
      new_odds[] <- NA_real_
      new_odds[which(odds <= -100)] <-
        -100 / odds[which(odds <= -100)]
      new_odds[which(odds >= 100)] <- odds[which(odds >= 100)] / 100
      new_odds <- MASS::fractions(new_odds)
    }
    if (output == "prob") {
      new_odds <- implied_prob(odds, type = "us")
    }
    if (output == "us") {
      new_odds <- odds
    }
  }

  ## Decimal Odds
  if (input == "dec") {
    if (output == "all") {
      dec <- odds
      frac <- odds - 1
      frac <- MASS::fractions(frac)

      us <- odds
      us[] <- NA_real_
      us[which(odds > 1)] <- -100 / (odds[which(odds > 1)] - 1)
      us[which(odds > 2)] <- 100 * (odds[which(odds > 2)] - 1)
      us <- round(us)

      new_odds <- data.frame(
        Decimal = odds,
        American = us,
        Fraction = as.character(frac),
        Implied_Probability = implied_prob(odds, type = "dec")
      )
    }
    if (output == "dec") {
      new_odds <- odds
    }
    if (output == "frac") {
      odds <- odds - 1
      new_odds <- MASS::fractions(odds)
    }
    if (output == "prob") {
      new_odds <- implied_prob(odds, type = "dec")
    }
    if (output == "us") {
      new_odds <- odds
      new_odds[] <- NA_real_
      new_odds[which(odds > 1)] <-
        -100 / (odds[which(odds > 1)] - 1)
      new_odds[which(odds > 2)] <- 100 * (odds[which(odds > 2)] - 1)
      new_odds <- round(new_odds)
    }
  }
  ## Fractional Odds
  if (input == "frac") {
    if (output == "all") {
      dec <- odds + 1
      frac <- MASS::fractions(odds)

      us <- odds
      us[] <- NA_real_
      us[which(dec > 1)] <- -100 / (dec[which(dec > 1)] - 1)
      us[which(dec > 2)] <- 100 * (dec[which(dec > 2)] - 1)
      us <- round(us)

      new_odds <- data.frame(
        Decimal = dec,
        American = us,
        Fraction = as.character(frac),
        Implied_Probability = implied_prob(odds = odds, type = "frac")
      )
    }
    if (output == "dec") {
      new_odds <- odds + 1
    }
    if (output == "frac") {
      new_odds <- MASS::fractions(odds)
    }
    if (output == "prob") {
      new_odds <- implied_prob(odds = odds, type = "frac")
    }
    if (output == "us") {
      odds <- odds + 1
      new_odds <- odds
      new_odds[] <- NA_real_
      new_odds[which(odds > 1)] <-
        -100 / (odds[which(odds > 1)] - 1)
      new_odds[which(odds > 2)] <- 100 * (odds[which(odds > 2)] - 1)
      new_odds <- round(new_odds)
    }
  }
  ## Probabilities
  if (input == "prob") {
    if (output == "all") {
      new_odds <-
        data.frame(
          Decimal = implied_odds(odds, type = "dec"),
          American = implied_odds(odds, type = "us"),
          Fraction = as.character(implied_odds(odds, type = "frac")),
          Implied_Probability = odds
        )
    }
    if (output == "dec") {
      new_odds <- implied_odds(odds, type = "dec")
    }
    if (output == "frac") {
      new_odds <- implied_odds(odds, type = "frac")
    }
    if (output == "prob") {
      new_odds <- odds
    }
    if (output == "us") {
      new_odds <- implied_odds(odds, type = "us")
    }
  }
  return(new_odds)
}