Removing NA in dplyr pipe [duplicate]

问题:

This question already has an answer here:

• filter for complete cases in data.frame using dplyr (case-wise deletion) 6 answers

I tried to remove NA's from the subset using dplyr piping. Is my answer an indication of a missed step. I'm trying to learn how to write functions using dplyr:

> outcome.df%>%
+ group_by(Hospital,State)%>%
+ arrange(desc(HeartAttackDeath,na.rm=TRUE))%>%
+ head()
Source: local data frame [6 x 5]
Groups: Hospital, State

                           Hospital State HeartAttackDeath
1     ABBEVILLE AREA MEDICAL CENTER    SC               NA
2        ABBEVILLE GENERAL HOSPITAL    LA               NA
3      ABBOTT NORTHWESTERN HOSPITAL    MN             12.3
4   ABILENE REGIONAL MEDICAL CENTER    TX             17.2
5        ABINGTON MEMORIAL HOSPITAL    PA             14.3
6 ABRAHAM LINCOLN MEMORIAL HOSPITAL    IL               NA
Variables not shown: HeartFailureDeath (dbl), PneumoniaDeath
  (dbl)

回答1:

I don't think desc takes an na.rm argument... I'm actually surprised it doesn't throw an error when you give it one. If you just want to remove NAs, use na.omit:

outcome.df %>%
  na.omit() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

If you only want to remove NAs from the HeartAttackDeath column, filter with is.na:

outcome.df %>%
  filter(!is.na(HeartAttackDeath)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

As pointed out at the dupe, complete.cases can also be used, but it's a bit trickier to put in a chain because it takes a data frame as an argument but returns an index vector. So you could use it like this:

outcome.df %>%
  filter(complete.cases(.)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()