Print number as reduced fraction in R

On my old beat-up TI-83 I can get a reduced fraction representation of a rational real number with the following syntax.

.14>Frac
               7/50

Is there a similar syntax, function, or开发者_如何学编程 CRAN package that will allow me to do this in R?

---

fractions() in the MASS package does just that:

> library(MASS)
> fractions(.14)
[1] 7/50

---

Another possibility is to use reduce.fraction from phonTools, but this requires a ratio of whole numbers:

library(phonTools)

frac <- function(x) {
  denom <- 10^(nchar(x %% 1) - 2)
  num <- trunc(x * denom)
  reduce.fraction(c(num, denom))
}

frac(.14)
[1]  7 50

# for multiple numbers must vectorize
vfrac <- Vectorize(frac, "x")
vfrac(c(.14, .375))
     [,1] [,2]
[1,]    7    3
[2,]   50    8

This allows for an easy retrieval of the numerator and denominator and values can easily be formatted to create a fraction:

paste(frac(.14), collapse = "/"))
[1] "7/50"

---

#Steps:
#1. Convert the data into fractions using fractions() from the MASS package.
#2. Convert the matrix to character.
#3. Convert to data frame.
#4. Then use gt().

#Example
if (!require("gt")) install.packages("gt")
if (!require("MASS")) install.packages("MASS")
library(gt)
library(MASS)

#Let us have some data using discrete joint probability distribution

JointDist <- function(xvector,yvector){
  i <- 0
  j <- 0
  entries <- matrix(nrow = length(xvector), ncol = length(yvector))
  for (x in min(xvector):max(xvector)) {
    i = i+1
    j <- 0 #reset j
    for (y in min(yvector):max(yvector)) {
      j = j+1
      entries[i,j] <- (2*x+y)/42 #change the expression according to the given
    }
  }
  entries
}
xvect <- 0:2
yvect <- 0:3

#This is the data in decimal format
mydata <- JointDist(xvect, yvect)
mydata

#This is the data in fraction format
mydata <- fractions(JointDist(xvect, yvect))
mydata

#Rename the columns and rows
colnames(mydata) <- paste0("yequals_",yvect)
rownames(mydata) <- paste0("xequals_", xvect)
mydata

#Get the marginal function of x and y and combine in the matrix
#The last column is the marginal probability function of x
#The last row is the marginal probability function of y

mydata <- fractions(cbind(mydata, marginalPFx = rowSums(mydata)))
mydata <- fractions(rbind(mydata, marginalPFy = colSums(mydata)))
mydata

#convert to data frame
df <- data.frame(Headers = row.names(mydata), mydata)
df

#Notice that it did not retain the fraction format.
gt(df)

#The secret is to change mydata to character before converting it to data frame
mydata <- as.character(mydata)

#convert to data frame
df <- data.frame(Headers = row.names(mydata), mydata)
df

#Now, it retains the fraction format.
gt(df)

#Add some title
if (!require("dplyr")) install.packages("dplyr")
library(dplyr)

gt(df) %>% 
  tab_header(
  title = md("**JOINT PROBABILITY DISTRIBUTION**"),
  subtitle = md("***f(x,y) = (2x+y)/42***"))

#That's it!