is_positive_integer {chinese.misc}

A Convenient Version of is.integer

Description

This function checks if all elements of an object can be taken to be valid integers.

Usage

is_positive_integer(x, len = NULL)

Arguments

x

an object to be checked

len

numeric vector specifying the allowed length of the x. If the length of the checked object is not in len, the function will return FALSE, even when it is a positive integer vector. The default is NULL, which means any length is OK.

Details

The reasons to use is_positive_integer are:

• (1) We often check if an object is a vector of positive integer. But is.numeric cannot do this because it also returns TRUE for a numeric matrix.

• (2) Sometimes is.integer returns a too strict result. For example, is.integer(3.0) returns FALSE, but the number 3.0 is valid in codes such as rep(10, 3.0), that is to say, as long as a number can be taken to be a valid integer, we take it to be a integer, even when is.integer returns FALSE.

• (3) is_positive_integer returns FALSE for length = 0 object, even when it is integer(0). To let the function return this result is because integer of length 0 is a invalid input for many functions.

• (4) is_positive_integer returns FALSE for any object that contains NA, so that object that gets a TRUE from this function is more likely to be a valid value to be passed to other functions.

Value

TRUE or FALSE

Examples

is_positive_integer(NULL)
is_positive_integer(as.integer(NA))
is_positive_integer(integer(0))
is_positive_integer(3.0)
is_positive_integer(3.3)
is_positive_integer(1:5)
is_positive_integer(1:5, len = c(2, 10))
is_positive_integer(1:5, len = c(2:10))