We can sum the elements of a vector using the sum() function.
Similarly, mean() and prod() functions can be used to find the mean and product of the terms.
Example: Vector Elements Arithmetic
> sum(2,7,5)
[1] 14
> x
[1] 2 NA 3 1 4
> sum(x) # if any element is NA or NaN, result is NA or NaN
[1] NA
> sum(x, na.rm=TRUE) # this way we can ignore NA and NaN values
[1] 10
> mean(x, na.rm=TRUE)
[1] 2.5
> prod(x, na.rm=TRUE)
[1] 24
Whenever a vector contains NA (Not Available) or NaN (Not a Number), functions such as sum(), mean(), prod() etc. produce NA or NaN respectively.
In order to ignore such values, we pass in the argument na.rm = TRUE.