Determine the number of NA values in a column

Question

I want to count the number of NA values in a data frame column  Say my data frame is called df  and the name of the column I am considering is col  The way I have come up with is following     sapply df col  function x  sum length which is na x          Is this a good most efficient way to do this

User · Answer

This form  slightly changed from Kevin Ogoros s one   na count  lt -function  x  sapply x  function y  sum is na y      returns NA counts as named int array

User · Answer

A tidyverse way to count the number of nulls in every column of a dataframe   library tidyverse  library purrr   df   gt       map df function x  sum is na x      gt       gather feature  num nulls    gt       print n   100

User · Answer

In the summary   output  the function also counts the NAs so one can use this function if one wants the sum of NAs in several variables

User · Answer

In the interests of completeness you can also use the useNA argument in table  For example table df col  useNA  quot always quot   will count all of non NA cases and the NA ones

User · Answer

You re over-thinking the problem   sum is na df col

User · Answer

If you are looking for NA counts for each column in a dataframe then   na count  lt -sapply x  function y  sum length which is na y        should give you a list with the counts for each column   na count  lt - data frame na count    Should output the data nicely in a dataframe like   ----------------------   row names   na count ------------------------   column 1    count

User · Answer

Try the colSums function  df  lt - data frame x   c 1 2 NA   y   rep NA  3    colSums is na df     x y   1 3

User · Answer

A quick and easy Tidyverse solution to get a NA count for all columns is to use summarise all   which I think makes a much easier to read solution than using purrr or sapply  library tidyverse    Example data df  lt - tibble col1   c 1  2  3  NA                 col2   c NA  NA   a    b     df   gt   summarise all   sum is na        gt    A tibble  1 x 2   gt     col1  col2   gt     lt int gt   lt int gt    gt  1     1     2

User · Answer

If you are looking to count the number of NAs in the entire dataframe you could also use  sum is na df

User · Answer

User rrs answer is right but that only tells you the number of NA values in the particular column of the data frame that you are passing to get the number of NA values for the whole data frame try this   apply  lt name of dataFrame gt   2 lt for getting column stats gt   function x   sum is na x       This does the trick

User · Answer

You can use this to count number of NA or blanks in every column  colSums is na data set name  data set name

User · Answer

I read a csv file from local directory  Following code works for me       to get number of which contains na sum is na df   c columnName      to get number of na row    to get number of which not contains na sum  is na df   c columnName       here columnName is your desire column name

User · Answer

sapply name of the data  function x  sum is na x

User · Answer

Try this   length df col is na df col

User · Answer

Similar to hute37 s answer but using the purrr package  I think this tidyverse approach is simpler than the answer proposed by AbiK   library purrr  map dbl df   sum is na        Note  the tilde     creates an anonymous function  And the     refers to the input for the anonymous function  in this case the data frame df

[r] Determine the number of NA values in a column

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