> tempdub

      Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec

1964 24.7 25.7 30.6 47.5 62.9 68.5 73.7 67.9 61.1 48.5 39.6 20.0

1965 16.1 19.1 24.2 45.4 61.3 66.5 72.1 68.4 60.2 50.9 37.4 31.1

1966 10.4 21.6 37.4 44.7 53.2 68.0 73.7 68.2 60.7 50.2 37.2 24.6

1967 21.5 14.7 35.0 48.3 54.0 68.2 69.6 65.7 60.8 49.1 33.2 26.0

1968 19.1 20.6 40.2 50.0 55.3 67.7 70.7 70.3 60.6 50.7 35.8 20.7

1969 14.0 24.1 29.4 46.6 58.6 62.2 72.1 71.7 61.9 47.6 34.2 20.4

1970  8.4 19.0 31.4 48.7 61.6 68.1 72.2 70.6 62.5 52.7 36.7 23.8

1971 11.2 20.0 29.6 47.7 55.8 73.2 68.0 67.1 64.9 57.1 37.6 27.7

1972 13.4 17.2 30.8 43.7 62.3 66.4 70.2 71.6 62.1 46.0 32.7 17.3

1973 22.5 25.7 42.3 45.2 55.5 68.9 72.3 72.3 62.5 55.6 38.0 20.4

1974 17.6 20.5 34.2 49.2 54.8 63.8 74.0 67.1 57.7 50.8 36.8 25.5

1975 20.4 19.6 24.6 41.3 61.8 68.5 72.0 71.1 57.3 52.5 40.6 26.2

month.=season(tempdub)

> model2=lm(tempdub~month.-1)

请问这是什么模型啊？

model3=lm(tempdub~month.)这是什么模型？