R语言创建函数代入具体值后显示object not found.

library(RQuantLib)
apr = function(price0 = price0,
               pricet = pricet,
               date0,
               datet,
               calendar){
    days = businessDaysBetween(calender,from = date0, to = datet)
    annual_r = (((pricet-price0)/price0)^(1/days))^365 - 1
    return(annual_r)
               }
apr(price0 = 166, pricet = 183.5,date0 = as.Date('2021-01-01'),datet = as.Date('2021-02-15'), calendar = 'UnitedStates/NYSE')
apr

apr(price0 = 166, pricet = 183.5,date0 = as.Date('2021-01-01'),datet = as.Date('2021-02-15'), calendar = 'UnitedStates/NYSE')
Error in businessDaysBetween(calender, from = date0, to = datet) : 
  object 'calender' not found

想请位帮忙看一下出了什么问题？

这里是计算两个日期间的收益率，并把它转化成年收益率，这里引入了一个RQuantLib的包，因此自带了一个businessDaysBetween,但是运行之后却说object not found.