assertthat (version 0.2.1)

scalar: Assert input is a scalar.

Description

is.scalar provides a generic method for checking input is a scalar. is.string, is.flag, is.number and is.count provide tests for specific types.

Usage

is.scalar(x)
is.string(x)
is.number(x)
is.flag(x)
is.count(x)

Arguments

x

object to test

See Also

Other assertions: are_equal, is.error, noNA, not_empty

Examples

# NOT RUN {
# Generic check for scalars
see_if(is.scalar("a"))
see_if(is.scalar(1:10))

# string = scalar character vector
see_if(is.string(1:3))
see_if(is.string(c("a", "b")))
see_if(is.string("x"))

# number = scalar numeric/integer vector
see_if(is.number(1:3))
see_if(is.number(1.5))

# flag = scalar logical vector
see_if(is.flag(1:3))
see_if(is.flag("a"))
see_if(is.flag(c(FALSE, FALSE, TRUE)))
see_if(is.flag(FALSE))

# count = scalar positive integer
see_if(is.count("a"))
see_if(is.count(-1))
see_if(is.count(1:5))
see_if(is.count(1.5))
see_if(is.count(1))

# }