Converting R object to Basic

Source: R/basic.R

`S` and `Basic` converts a R object to a Basic object. `Symbol`, `Real` and `Constant` construct a Basic object with type "Symbol", "RealDouble"/"RealMPFR" and "Constant", respectively.

S(x)

Basic(x)

Symbol(x)

Constant(x)

Real(x, prec = NULL)

Arguments

x

A R object.

prec

If supplied, the argument will be parsed as a Basic object of type RealMPFR.

Value

A Basic S4 object.

Details

For double vector, `S` will check whether it is a whole number -- if true, it will be converted to a Integer type. If this behavior is not desired, you can use `Basic` or `as(x, "Basic")`.

Examples

S("(x + y)^2")
#> (Pow)	(x + y)^2
S(~ (x + y)^2)
#> (Pow)	(x + y)^2
S(NaN)
#> (NaN)	NaN
S(42)
#> (Integer)	42
Basic(42)
#> (RealDouble)	42.0
as(42, "Basic")
#> (RealDouble)	42.0
pi <- Constant("pi")
evalf(pi)
#> (RealDouble)	3.14159265358979
if (symengine_have_component("mpfr"))
    evalf(pi, 300)
#> (RealMPFR,prec300)	3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348
Real(42)
#> (RealDouble)	42.0
if (symengine_have_component("mpfr"))
    Real(42, prec = 140)
#> (RealMPFR,prec140)	42.000000000000000000000000000000000000000