Return values from the NA row of a factor column

Question

In R, I used janitor::tabyl to produce a frequency table of my factor variable Mp.

data_mp <- janitor::tabyl(data, Mp, show_na = TRUE)

It gaves me:

Mp	n	percent	valid_percent
FCA	4848	5.66%	6.38%
FCA-TESLA	6629	7.74%	8.72%
FCA ITALY SPA	8700	10.16%	11.44%
FIAT GROUP AUTOMOBILES SPA	451	0.53%	0.59%
FORD-VOLVO	2780	3.25%	3.66%
HYUNDAI	4609	5.38%	6.06%
MERCEDES-BENZ	7366	8.60%	9.69%
TATA MOTORS JAGUAR LAND ROVER	4832	5.64%	6.36%
VW-SAIC	9289	10.85%	12.22%
VW GROUP PC	26526	30.98%	34.89%
NA	9606	11.22%	NA

Now I would like to use the number of NA observations and its percentage.
I tried with data_mp["NA", "n"] but it returns me NA.

How do you return the values in the NA row of a factor column?

Edit

I managed to recover the number of observations by doing: data_mp[is.na(data_mp$Mp),"n"].
But I'm not sure this is the right way.

Answer 1

It is not a row name, but the value in column 'Mp', so we extract the column 'Mp' with $ or [[, apply is.na (to check for the NA row instead of == "NA"), use that as row index

data_mp[is.na(data_mp$Mp), "n"]
[1] 31

data

data <- data.frame(Mp = sample(c(LETTERS[1:10], NA), 300, replace = TRUE))
data_mp <- janitor::tabyl(data, Mp, show_na = TRUE)