如何将分数表达式转换为 R 中的字符向量？

Question

Hello an thanks for the help.

I want to convert the expression: x / y (eg 1298 / 1109) into a character vector: "x / y" (eg "1298 / 1109") using R.

I have tried it with as.character(x/y) and with as.character.Date(x/y) but this only turns the result of the fraction into a character vector.

Answer 1

Do you mean this?

> deparse(quote(1298 / 1109))
[1] "1298/1109"

or

> f <- function(x) deparse(substitute(x))

> f(1298 / 1109)
[1] "1298/1109"

Answer 2

An alternative solution using paste , as mentioned by Allan in the comments, wrapped in a function. Not as flexible as the solution by Tomas, but simple.

f <- function(x,y) {
  paste(x, y, sep = " / ")
}

f(1298, 1109)

[1] "1298 / 1109"

Answer 3

As an addition to the excellent answers already given, in case that one wants to be able to evaluate the expression at some point you can take this approach.

x <- 1298
y <- 1109

z <- as.expression(substitute(x / y, list(x = x, y = y)))

z
# expression(1298/1109)

class(z)
# [1] "expression"

eval(z)
# [1] 1.1704

as.character(z)
# [1] "1298/1109"

Or without making it an expression

t <- substitute(x / y, list(x = x, y = y))

t
# 1298/1109 # not a string, but a "call"

class(t)
# [1] "call"

eval(t)
# [1] 1.1704

deparse(t)
# [1] "1298/1109"

Answer 4

With MASS , there is fractions function

 MASS::fractions(1298/1109)
[1] 1298/1109