我每年都有关于二氧化碳生产的数据。目前没有可用的数据，可以追溯到1880年。我希望将年平均值（比如1881年）作为每年1月到12月之间每月的月平均值。我怎么能在R中这样做？
答案 0 :(得分：0)
假设您有两个看起来像
的data.framesco2month <- data.frame(year=rep(1900:1902,each=12), month=rep(month.abb,3), co2=rnorm(36))
co2month
# year month co2
# 1 1900 Jan 1.76168513
# 2 1900 Feb -1.62766625
# 3 1900 Mar 0.17191233
# 4 1900 Apr -1.86788375
# 5 1900 May -1.91116179
# 6 1900 Jun 1.52547400
# 7 1900 Jul 0.55842987
# 8 1900 Aug -0.02160731
# 9 1900 Sep -0.22032746
# 10 1900 Oct -1.00799922
# 11 1900 Nov 0.48254329
# 12 1900 Dec 0.65806450
# 13 1901 Jan 0.34173786
# 14 1901 Feb 0.24271387
# 15 1901 Mar 0.10781086
# 16 1901 Apr 0.84838652
# 17 1901 May -0.33528728
# 18 1901 Jun 1.08970247
# 19 1901 Jul 0.54564873
# 20 1901 Aug -0.08503711
# 21 1901 Sep -0.64936354
# 22 1901 Oct -0.38287041
# 23 1901 Nov -1.31713823
# 24 1901 Dec 0.35556969
# 25 1902 Jan -0.84373047
# 26 1902 Feb -0.53323007
# 27 1902 Mar 0.30167420
# 28 1902 Apr 0.64759628
# 29 1902 May -0.15417477
# 30 1902 Jun 0.77399708
# 31 1902 Jul 0.07909732
# 32 1902 Aug -1.81445087
# 33 1902 Sep -0.14126574
# 34 1902 Oct -0.37610929
# 35 1902 Nov -1.15516717
# 36 1902 Dec 0.77210347
和
co2year <- data.frame(year=1897:1899, co2=rnorm(3))
co2year
# year co2
# 1 1897 -0.75838749
# 2 1898 -1.61749706
# 3 1899 -0.04063466
你可以扩展早期的'co2year}数据并附加两个数据集
# expanding
co2month1 <- data.frame(year=rep(co2year$year,each=12), month=rep(month.abb,3), co2=rep(co2year$co2,each=12))
# appending
co2month_appended <- rbind(co2month1, co2month)
# results
co2month_appended
# year month co2
# 1 1897 Jan -0.75838749
# 2 1897 Feb -0.75838749
# 3 1897 Mar -0.75838749
# 4 1897 Apr -0.75838749
# 5 1897 May -0.75838749
# 6 1897 Jun -0.75838749
# 7 1897 Jul -0.75838749
# 8 1897 Aug -0.75838749
# 9 1897 Sep -0.75838749
# 10 1897 Oct -0.75838749
# 11 1897 Nov -0.75838749
# 12 1897 Dec -0.75838749
# 13 1898 Jan -1.61749706
# 14 1898 Feb -1.61749706
# 15 1898 Mar -1.61749706
# 16 1898 Apr -1.61749706
# 17 1898 May -1.61749706
# 18 1898 Jun -1.61749706
# 19 1898 Jul -1.61749706
# 20 1898 Aug -1.61749706
# 21 1898 Sep -1.61749706
# 22 1898 Oct -1.61749706
# 23 1898 Nov -1.61749706
# 24 1898 Dec -1.61749706
# 25 1899 Jan -0.04063466
# 26 1899 Feb -0.04063466
# 27 1899 Mar -0.04063466
# 28 1899 Apr -0.04063466
# 29 1899 May -0.04063466
# 30 1899 Jun -0.04063466
# 31 1899 Jul -0.04063466
# 32 1899 Aug -0.04063466
# 33 1899 Sep -0.04063466
# 34 1899 Oct -0.04063466
# 35 1899 Nov -0.04063466
# 36 1899 Dec -0.04063466
# 37 1900 Jan 1.76168513
# 38 1900 Feb -1.62766625
# 39 1900 Mar 0.17191233
# 40 1900 Apr -1.86788375
# 41 1900 May -1.91116179
# 42 1900 Jun 1.52547400
# 43 1900 Jul 0.55842987
# 44 1900 Aug -0.02160731
# 45 1900 Sep -0.22032746
# 46 1900 Oct -1.00799922
# 47 1900 Nov 0.48254329
# 48 1900 Dec 0.65806450
# 49 1901 Jan 0.34173786
# 50 1901 Feb 0.24271387
# 51 1901 Mar 0.10781086
# ... and so on ...
至于是否适当来估算年度平均值，我会留给你（主题专家）来决定。