The function sumNA returns the sum of all the values in its arguments.
Contrarily to sum, it returns NA instead of 0 when the input
contains only missing values and missing values are removed.
Usage
sumNA(..., na.rm = FALSE)
Arguments
...
numeric or complex or logical vectors.
na.rm
logical. Should missing values (including NaN) be removed?
Value
The sum. Returns NA if x contains only missing values
and na.rm = TRUE.