Finding cases that have no missing values

The complete.cases() function takes a data frame or table as its argument and returns a Boolean vector with TRUE for rows that have no missing values, and FALSE otherwise:

> complete.cases(dat) 
 
 [1]  TRUE  TRUE  TRUE FALSE  TRUE FALSE  TRUE  TRUE  TRUE 
[10]  TRUE  TRUE  TRUE FALSE  TRUE  TRUE  TRUE FALSE  TRUE 
[19]  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE 

Rows 4, 6, 13, and 17 have at least one missing value. Instead of using the na.omit() function, we can do the following as well:

> dat.cleaned <- dat[complete.cases(dat),] 
> nrow(dat.cleaned) 
[1] 23