check_n | R Documentation |
Check if an argument is a single natural number, and if not, generate an error message.
Can be used to check indices, for example.
check_n(
x,
name = NULL,
general = NULL,
specific = NULL,
supplement = NULL,
zero = FALSE,
...
)
is_n(x, zero = FALSE)
x |
The argument to check, which can be any object. |
name |
A single character which gives the argument's name.
The name is used in the error message. By default, the name of the
argument passed to argument |
general |
Optional. A single character which is used to give a general statement of the error incurred. By default, this is generated automatically. |
specific |
Optional. A single character which gives a detailed description of the error. By default, this is generated automatically. |
supplement |
Optional. A (named) character vector which gives some
additional information about the error. The names are used to create
bullets, see |
zero |
Optional. |
... |
Optional. Additional arguments which can be retrieved with
|
check_n()
returns an invisible NULL
if the argument
is valid, or it generates an error message.
is_n()
returns TRUE
or FALSE
.
"Examples" section in check_type()
for how to customize
error message and how to add and retrieve additional arguments.
vignette("erify")
for a gentle introduction to this package.
x <- 1
check_n(x)
x <- 1L
check_n(x)
sapply(c(1, 2.1, 0, Inf, NA, -9), is_n)
## Not run:
# `x` must be a numeric
x <- "1"
check_n(x)
# `x` must have length 1
x <- 1:2
check_n(x)
# `x` must not be `NA`
x <- NA_integer_
check_n(x)
# `x` must be larger than 0
x <- -1
check_n(x)
# `x` must be an integer in a mathematical sense
x <- 1.1
check_n(x)
# make `0` acceptable
x <- 0
check_n(x)
check_n(x, zero = TRUE)
## End(Not run)
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