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Check if Argument is a Positive Scalar

Source: R/check_scalar_sign.R
check_scalar_sign.Rd

Check if argument is a positive integer or numeric.

Usage

check_scalar_sign(
  x,
  arg_sign = "positive",
  arg_equal = FALSE,
  alt_null = FALSE,
  add_msg = NULL
)

Arguments

x

Function argument that is being asserted. Needs to be an integer or a numeric scalar.

arg_sign

Character. It can take value "positive" or "negative".

arg_equal

Logical. If TRUE it will include 0 as a valid option ( in other words it will check if x is non negative or non positive).

alt_null

Logical. Should argument accept NULL value.

add_msg

Is an additional message that can be printed over the standard function error message. You can:

  • pass the names of the arguments that failed the test by using {x_names} in the message body (e.g. "What are the {x_names}");

  • pass the tested sign by using {arg_sign} in the message body (e.g. "I want them to be {arg_sign})".

Value

If argument is of class returns invisible NULL, otherwise it throws an error.

Examples

pi <- 4L
pn <- 21.37
ni <- -666L
nn <- -505.606
pi2 <- c(2L, 18L)
pn2 <- c(85.86, 11.09)
ni2 <- c(-123L, -66L)
nn2 <- c(-3.14, -0.001)
zi1 <- 0
if (FALSE) { # \dontrun{
check_scalar_sign(pi, arg_sign = "negative")
check_scalar_sign(nn, arg_sign = "positive")
check_scalar_sign(pn2, arg_sign = "negative", alt_null = TRUE)
check_scalar_sign(ni, arg_sign = "positive",
  add_msg = "{.arg {x_name}} is not {.val {arg_sign}}"
)
check_scalar_sign(zi1, arg_sign = "positive", arg_equal = TRUE)
check_scalar_sign(zi1, arg_sign = "negative", arg_equal = TRUE)
check_scalar_sign(zi1, arg_sign = "positive", arg_equal = FALSE)
check_scalar_sign(
  zi1, arg_sign = "negative", arg_equal = FALSE, alt_null = TRUE
)
} # }