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Is there an R function that accepts an R object and returns code that can be run to generate that object?

Example

When passed the first 5 rows of the iris dataframe

iris
# Sepal.Length Sepal.Width Petal.Length Petal.Width Species
# 1          5.1         3.5          1.4         0.2  setosa
# 2          4.9         3.0          1.4         0.2  setosa
# 3          4.7         3.2          1.3         0.2  setosa
# 4          4.6         3.1          1.5         0.2  setosa
# 5          5.0         3.6          1.4         0.2  setosa

The function would generate the following string like so:

string <- "data.frame(\"Sepal.Length\"=as.numeric(c(5.1, 4.9, 4.7, 4.6, 5.0)), \"Sepal.Width\"=as.numeric(c(3.5, 3.0, 3.2, 3.1, 3.6)), \"Petal.Length\"=as.numeric(c(1.4, 1.4, 1.3, 1.5, 1.4)), \"Petal.Width\"=as.numeric(c(0.2, 0.2, 0.2, 0.2, 0.2)), \"Species\"=as.factor(c(\"setosa\", \"setosa\", \"setosa\", \"setosa\", \"setosa\")), stringsAsFactors = FALSE)"

Then calling cat(string) would print to console the exact code necessary to generate the object (in this case, a dataframe)

data.frame("Sepal.Length"=as.numeric(c(5.1, 4.9, 4.7, 4.6, 5.0)), "Sepal.Width"=as.numeric(c(3.5, 3.0, 3.2, 3.1, 3.6)), "Petal.Length"=as.numeric(c(1.4, 1.4, 1.3, 1.5, 1.4)), "Petal.Width"=as.numeric(c(0.2, 0.2, 0.2, 0.2, 0.2)), "Species"=as.factor(c("setosa", "setosa", "setosa", "setosa", "setosa")), stringsAsFactors = FALSE)

Does such a function exist?

stevec
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    you can use `dput`. It would give you exact code to create the object passed. `dput(iris[1:5, ])` – Ronak Shah Jan 30 '19 at 07:05
  • Relevant: https://stackoverflow.com/questions/18746456/simplified-dput-in-r – NelsonGon Jan 30 '19 at 08:53
  • I'm voting to reopen this question. There's a great answer (and additional answer in the comment above, but there's still no reason for it to be closed. Also, the close reason is for 'seeking recommendations for books, tools' but it doesn't do that at all, it asks for R code/function(s) like every other [R] tag question. – stevec Apr 03 '23 at 01:52

1 Answers1

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I think you are looking for dput.

For example, for 1st 5 rows of iris, you could do 

dput(iris[1:5,])

#structure(list(Sepal.Length = c(5.1, 4.9, 4.7, 4.6, 5), Sepal.Width = c(3.5, 
#3, 3.2, 3.1, 3.6), Petal.Length = c(1.4, 1.4, 1.3, 1.5, 1.4), 
#    Petal.Width = c(0.2, 0.2, 0.2, 0.2, 0.2), Species = structure(c(1L, 
#    1L, 1L, 1L, 1L), .Label = c("setosa", "versicolor", "virginica"
#    ), class = "factor")), .Names = c("Sepal.Length", "Sepal.Width", 
#"Petal.Length", "Petal.Width", "Species"), row.names = c(NA, 
#5L), class = "data.frame")

and now you could use the same code to recreate the object again.

Another example, 

x <- c(3, 4, 1, 2)
dput(x)
#c(3, 4, 1, 2)
Ronak Shah
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  • From R documentation: "dput {base} - Writes an ASCII text representation of an R object to a file or connection, or uses one to recreate the object.". I had not come across this function before. It is exactly what I am after! Thank you – stevec Jan 30 '19 at 18:33