>BoxCox.ar(electricity)
There were 15 warnings (use warnings() to see them)
> warnings()
警告信息：
1: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
2: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
3: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
4: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
5: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
6: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
7: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
8: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
9: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
10: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
11: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
12: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
13: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
14: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1
15: In arima0(x, order = c(i, 0L, 0L), include.mean = demean) :
  possible convergence problem: optim gave code = 1

请问是什么意思？