使用group_by过滤特定情况，同时保持NAs [英] Use group_by to filter specific cases while keeping NAs

问题描述

我想过滤我的数据集，以便将具有观察值的案例保留在特定列中。说明：

I want to filter my dataset to keep cases with observations in a specific column. To illustrate:

help <- data.frame(deid = c(5, 5, 5, 5, 5, 12, 12, 12, 12, 17, 17, 17),
               score.a = c(NA, 1, 1, 1, NA, NA, NA, NA, NA, NA, 1, NA))

创建

   deid score.a
1     5      NA
2     5       1
3     5       1
4     5       1
5     5      NA
6    12      NA
7    12      NA
8    12      NA
9    12      NA
10   17      NA
11   17       1
12   17      NA

我想告诉dplyr保留在 score.a 中有任何意见的案例，包括NA值。因此，我希望它返回：

And I want to tell dplyr to keep cases that have any observations in score.a, including the NA values. Thus, I want it to return:

  deid score.a
1     5      NA
2     5       1
3     5       1
4     5       1
5     5      NA
6    17      NA
7    17       1
8    17      NA

我运行代码 help％>％group_by（deid）％>％filter（score.a> ; 0）然而它也拉出了NAs。感谢您的协助。

I ran the code help %>% group_by(deid) %>% filter(score.a > 0) however it pulls out the NAs as well. Thank you for any assistance.

编辑：在这里有一个类似的问题如何使用dplyr :: filter（）删除观察组
但是，在答案中他们使用'all'条件，这需要使用'any'条件。

A similar question was asked here How to remove groups of observation with dplyr::filter() However, in the answer they use the 'all' condition and this requires use of the 'any' condition.

推荐答案

尝试

library(dplyr)
help %>%
      group_by(deid) %>%
      filter(any(score.a >0 & !is.na(score.a)))
#    deid score.a
#1    5      NA
#2    5       1
#3    5       1
#4    5       1
#5    5      NA
#6   17      NA
#7   17       1
#8   17      NA

或类似的方法与 data.table

library(data.table)
setDT(help)[, if(any(score.a>0 & !is.na(score.a))) .SD , deid]
#    deid score.a
#1:    5      NA
#2:    5       1
#3:    5       1
#4:    5       1
#5:    5      NA
#6:   17      NA
#7:   17       1
#8:   17      NA

如果条件是将'deid'与'score.a'> 0中的所有值进行子集'，那么上述代码可以修改为

If the condition is to subset 'deid's with all the values in 'score.a' > 0, then the above code can be modified to,

setDT(help)[,  if(!all(is.na(score.a)) & 
         all(score.a[!is.na(score.a)]>0)) .SD , deid]
#   deid score.a
#1:    5      NA
#2:    5       1
#3:    5       1
#4:    5       1
#5:    5      NA
#6:   17      NA
#7:   17       1
#8:   17      NA

假设其中一个score.a 'deid'组小于0，

Suppose one of the 'score.a' in 'deid' group is less than 0,

help$score.a[3] <- -1

上述代码将返回

 setDT(help)[,  if(!all(is.na(score.a)) & 
           all(score.a[!is.na(score.a)]>0, deid],
 #   deid score.a
 #1:   17      NA
 #2:   17       1
 #3:   17      NA

这篇关于使用group_by过滤特定情况，同时保持NAs的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！