如何在数据框上使用 Coalesce 函数

Question

我试图找到一种方法来处理 NA 数据，但无法做到，请协助我。

我有以下数据，

R1 <- c("15515","5156","65656","1566", "2857","8888","65656","1566","65651")
R2 <- c("515","5156.11-","415-","1455-","886","888","777","666","4457")
RC1 <- c("AW","FG","ZA","ZI","","CW","","","")
RC2 <- c("SSSBB","","","ZXXQA","","CQAER","","KKHDY","TTQWW")
RC3 <- c("KKAJDJHW","XVVJAKWA","","","","CDDGAJJA","GGGAJTTD","","BBNMNJJI")
df <- data.frame(R1,R2,RC1,RC2,RC3)

我正在使用下面的代码来处理 RC1、RC2 和 RC3 中的 NA

df_1$RCC <- with(df_1, coalesce(df_1$RC3,df_1$RC2,df_1$RC1))
df_1

我无法从 RC1 和 RC2 获取数据。需要您的帮助。

Answer 1

要使 coalesce 正常工作，您需要 NA 而不是空白。将空格更改为 NA 并尝试：

library(dplyr)

df[df == ''] <- NA
df %>% mutate(RCC = coalesce(RC3, RC2, RC1))

#    R1       R2  RC1   RC2      RC3      RCC
#1 15515      515   AW SSSBB KKAJDJHW KKAJDJHW
#2  5156 5156.11-   FG  <NA> XVVJAKWA XVVJAKWA
#3 65656     415-   ZA  <NA>     <NA>       ZA
#4  1566    1455-   ZI ZXXQA     <NA>    ZXXQA
#5  2857      886 <NA>  <NA>     <NA>     <NA>
#6  8888      888   CW CQAER CDDGAJJA CDDGAJJA
#7 65656      777 <NA>  <NA> GGGAJTTD GGGAJTTD
#8  1566      666 <NA> KKHDY     <NA>    KKHDY
#9 65651     4457 <NA> TTQWW BBNMNJJI BBNMNJJI

Answer 2

我们也可以这样做而不必键入所有列名

library(dplyr)# >= 1.0.0    
df %>% 
    mutate(across(everything(), na_if, "")) %>%
    mutate(RCC = coalesce(!!! select(., RC3:RC1)))
#    R1       R2  RC1   RC2      RC3      RCC
#1 15515      515   AW SSSBB KKAJDJHW KKAJDJHW
#2  5156 5156.11-   FG  <NA> XVVJAKWA XVVJAKWA
#3 65656     415-   ZA  <NA>     <NA>       ZA
#4  1566    1455-   ZI ZXXQA     <NA>    ZXXQA
#5  2857      886 <NA>  <NA>     <NA>     <NA>
#6  8888      888   CW CQAER CDDGAJJA CDDGAJJA
#7 65656      777 <NA>  <NA> GGGAJTTD GGGAJTTD
#8  1566      666 <NA> KKHDY     <NA>    KKHDY
#9 65651     4457 <NA> TTQWW BBNMNJJI BBNMNJJI

如何在数据框上使用 Coalesce 函数

How to use Coalesce function on a dataframe

r

coalesce