Test is an object is integer or double
Numeric is used in three different ways in base R:
as an alias for double (as in as.numeric())
to mean either integer or double (as in mode())
for something representable as numeric (as in as.numeric())
This function tests for the second, which is often not what you want
so these functions are deprecated.
is_numeric(x) is_scalar_numeric(x)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.