r - 替换列r中的多个值

Question

我正在尝试创建一个函数，该函数需要两个变量，分别是大陆和要从数据框中使用的列。然后，我试图计算该特定大洲的列的平均值，以替换该大洲该列中的NA。但是，在实际替换值时似乎遇到了麻烦，我一直遇到错误。我尝试了多种方法，例如replace，replace_na和mutate，但我不断收到似乎无法摆脱的错误。这段代码不在函数中时起作用，但是在我将其添加到函数中的那一刻，我似乎收到此错误。

df<-structure(list(location = c("Algeria", "Angola", "Benin", "Botswana", 
"Burkina Faso", "Burundi"), iso_code = c("DZA", "AGO", "BEN", 
"BWA", "BFA", "BDI"), continent = c("Africa", "Africa", "Africa", 
"Africa", "Africa", "Africa"), date = c("2020-09-02", "2020-09-02", 
"2020-09-02", "2020-09-02", "2020-09-02", "2020-09-02"), total_cases = c(44833, 
2654, 2145, 1733, 1375, 445), new_cases = c(339, 30, 0, 9, 5, 
0), new_cases_smoothed = c(372.143, 53, 4.286, 24.429, 3.286, 
2.143), total_deaths = c(1518, 108, 40, 6, 55, 1), new_deaths = c(8, 
1, 0, 0, 0, 0), new_deaths_smoothed = c(8.857, 0.857, 0.143, 
0.429, 0, 0), total_cases_per_million = c(1022.393, 80.751, 176.934, 
736.937, 65.779, 37.424), new_cases_per_million = c(7.731, 0.913, 
0, 3.827, 0.239, 0), new_cases_smoothed_per_million = c(8.487, 
1.613, 0.354, 10.388, 0.157, 0.18), total_deaths_per_million = c(34.617, 
3.286, 3.299, 2.551, 2.631, 0.084), new_deaths_per_million = c(0.182, 
0.03, 0, 0, 0, 0), new_deaths_smoothed_per_million = c(0.202, 
0.026, 0.012, 0.182, 0, 0), population = c(43851043, 32866268, 
12123198, 2351625, 20903278, 11890781), population_density = c(17.348, 
23.89, 99.11, 4.044, 70.151, 423.062), median_age = c(29.1, 16.8, 
18.8, 25.8, 17.6, 17.5), aged_65_older = c(6.211, 2.405, 3.244, 
3.941, 2.409, 2.562), aged_70_older = c(3.857, 1.362, 1.942, 
2.242, 1.358, 1.504), gdp_per_capita = c(13913.839, 5819.495, 
2064.236, 15807.374, 1703.102, 702.225), extreme_poverty = c(0.5, 
NA, 49.6, NA, 43.7, 71.7), cardiovasc_death_rate = c(278.364, 
276.045, 235.848, 237.372, 269.048, 293.068), diabetes_prevalence = c(6.73, 
3.94, 0.99, 4.81, 2.42, 6.05), female_smokers = c(0.7, NA, 0.6, 
5.7, 1.6, NA), male_smokers = c(30.4, NA, 12.3, 34.4, 23.9, NA
), handwashing_facilities = c(83.741, 26.664, 11.035, NA, 11.877, 
6.144), hospital_beds_per_thousand = c(1.9, NA, 0.5, 1.8, 0.4, 
0.8), life_expectancy = c(76.88, 61.15, 61.77, 69.59, 61.58, 
61.58)), row.names = c(NA, -6L), class = c("tbl_df", "tbl", "data.frame"
))


fun1 <- function(cont, column)
{
  countries<-df%>%
    filter(continent == cont)
  
  m<-mean(countries[[column]],na.rm=T)

    df[,column]<-ifelse(is.na(df[,column]) & df$continent==cont,m,(df[,column]=df[,column]))
}

fun1("Europe","median_age")

错误:
包裹时发生错误:无法将大小为208的输入回收为大小1。
错误:没有更多可用的错误处理程序(递归错误？)；调用“中止”重启

Answer 1

您在这里遇到许多问题。首先是您似乎在复制dput时出错，因此示例代码无法运行。其次，您在函数中使用名称mean作为变量名，这很可能在以后引起调试困惑。第三是您的函数不返回任何东西。最后，您的间距使代码很难阅读。您有很多带有换行符的垂直空格，但不要用空格分隔变量名和运算符。同样，这使调试变得更困难。
如果您使用的是dplyr函数，则可以利用准引号来使代码更简单，更直观地使用。例如，您可以编写它以传递裸列名称，而不必将其包装在“双引号”中

fun1 <- function(cont, col)
{
  col <- enquo(col)
  
  filter(df, continent == cont) %>%
    mutate(!!col := replace(!!col, is.na(!!col), mean(!!col, na.rm = TRUE)))
}

所以你可以这样写:

fun1("Africa", new_cases)
#>       location iso_code continent       date total_cases new_cases new_cases_smoothed
#> 1      Algeria      DZA    Africa 2020-09-02       44833       339            372.143
#> 2       Angola      AGO    Africa 2020-09-02        2654        30             53.000
#> 3        Benin      BEN    Africa 2020-09-02        2145         0              4.286
#> 4     Botswana      BWA    Africa 2020-09-02        1733         9             24.429
#> 5 Burkina Faso      BFA    Africa 2020-09-02        1375         5              3.286
#> 6      Burundi      BDI    Africa 2020-09-02         445         0              2.143
#>   total_deaths new_deaths
#> 1         1518          8
#> 2          108          1
#> 3           40          0
#> 4            6          0
#> 5           55          0
#> 6            1          0

如果只想用该大陆其他国家/地区的平均值替换数字列中的所有NA值，则根本不需要任何函数。您可以使用:

df <- df %>% 
        group_by(continent) %>%
        mutate(across(total_cases:life_expectancy,
               function(x) replace(x, is.na(x), mean(x, na.rm = TRUE))))

转换整个数据帧。