运动R功能问题？

Question

K值和x值

x = GP$PDiff

k1 = 35*sin(0.0561*x)

k2 = -(1/7)*x + 39

k3 = 30

否则，如果有问题

if (x <= 28){{

  elo <- eloRating(home="HomeTeam", away="AwayTeam", homeScore="HomeScore", awayScore = "AwayScore",
                   data = GP, kfactor = k1, initialRating = 1500, homeAdvantage = 0)
}

  else if (x > 28|x <= 35){

    elo <- eloRating(home="HomeTeam", away="AwayTeam", homeScore="HomeScore", awayScore = "AwayScore",
                     data = GP, kfactor = k2, initialRating = 1500, homeAdvantage = 0)
  }

  else{
    elo <- eloRating(home="HomeTeam", away="AwayTeam", homeScore="HomeScore", awayScore = "AwayScore",
                     data = GP, kfactor = k3, initialRating = 1500, homeAdvantage = 0) 
  }
}

当我尝试运行它时，出现错误，提示“在'else'中出现了意外的'else'”，并且括号也存在错误