计算缺失值中断的数据范围 - R.

时间:2013-11-19 18:02:28

标签: r missing-data

我的数据示例如下:

site<-c("A","B","C","D")
year1<-c(1990,1990,1990,1990)
year2<-c("",1991,1991,1991)
year3<-c(1992,1992,1992,1992)
year4<-c(1993,"",1993,"")
year5<-c(1994,1994,1994,1994)
dat<-data.frame(site,year1,year2,year3,year4,year5)

我想计算每一行(或本例中的网站)的数据范围,但我想包括存在缺失值的中断。

所以创建一个类似于此类的列。

dat$year_range<-c("1990, 1992-1994","1990-1992, 1994","1990-1994","1990-1992, 1994")

感谢。

2 个答案:

答案 0 :(得分:2)

这里有一些正则表达式(从里到外阅读/尝试):

gsub(',+', ',', # final cleanup of multiple commas
  gsub('(^,+|,+$)', '',  # cleanup of commas at end of start
    # the meat - take out adjacent years and replace them with a '-'
    gsub('((?<=,,)|^)([0-9]+),([0-9]+,)+([0-9]+)((?=,,)|$)',
        ',\\2-\\4,',
        apply(dat[, -1], 1, paste, collapse = ","), perl = TRUE)))
#[1] "1990,1992-1994" "1990-1992,1994" "1990-1994"      "1990-1992,1994"

答案 1 :(得分:2)

这是一个提案,我想它可以用更简单的方式完成:

dat$year_range <- apply(dat[-1], 1, function(x) {
  x <- as.integer(x)
  paste(tapply(x[!is.na(x)], cumsum(is.na(x))[!is.na(x)], function(y) 
    paste(unique(range(y)), collapse = "-")), collapse = ", ")
})

#   site year1 year2 year3 year4 year5      year_range
# 1    A  1990        1992  1993  1994 1990, 1992-1994
# 2    B  1990  1991  1992        1994 1990-1992, 1994
# 3    C  1990  1991  1992  1993  1994       1990-1994
# 4    D  1990  1991  1992        1994 1990-1992, 1994