How to save data file into .RData?

Question

I want to save data into an .RData file.

For instance, I'd like to save into 1.RData with two csv files and some information.

Here, I have two csv files

1) file_1.csv contains object city[[1]]
2) file_2.csv contains object city[[2]]

and additionally save other values, country and population as follows. So, I guess I need to make objects 'city' from two csv files first of all.

The structure of 1.RData may looks like this:

> data = load("1.RData")

> data
[1] "city"  "country"  "population"

> city
  [[1]]               
  NEW YORK         1.1
  SAN FRANCISCO    3.1

  [[2]]
  TEXAS            1.3
  SEATTLE          1.4

> class(city)
  [1] "list"

> country
  [1] "east"  "west"  "north"

> class(country)
  [1] "character"

> population
  [1] 10  11  13  14   

> class(population)
  [1] "integer"

file_1.csv and file_2.csv have bunch of rows and columns.

How can I create this type of RData with csv files and values?

Answer 1

Alternatively, when you want to save individual R objects, I recommend using saveRDS.

You can save R objects using saveRDS, then load them into R with a new variable name using readRDS.

Example:

# Save the city object
saveRDS(city, "city.rds")

# ...

# Load the city object as city
city <- readRDS("city.rds")

# Or with a different name
city2 <- readRDS("city.rds")

But when you want to save many/all your objects in your workspace, use Manetheran's answer.

Answer 2

There are three ways to save objects from your R session:

Saving all objects in your R session:

The save.image() function will save all objects currently in your R session:

save.image(file="1.RData") 

These objects can then be loaded back into a new R session using the load() function:

load(file="1.RData")

Saving some objects in your R session:

If you want to save some, but not all objects, you can use the save() function:

save(city, country, file="1.RData")

Again, these can be reloaded into another R session using the load() function:

load(file="1.RData") 

Saving a single object

If you want to save a single object you can use the saveRDS() function:

saveRDS(city, file="city.rds")
saveRDS(country, file="country.rds") 

You can load these into your R session using the readRDS() function, but you will need to assign the result into a the desired variable:

city <- readRDS("city.rds")
country <- readRDS("country.rds")

But this also means you can give these objects new variable names if needed (i.e. if those variables already exist in your new R session but contain different objects):

city_list <- readRDS("city.rds")
country_vector <- readRDS("country.rds")

Answer 3

Just to add an additional function should you need it. You can include a variable in the named location, for example a date identifier

date <- yyyymmdd
save(city, file=paste0("c:\\myuser\\somelocation\\",date,"_RData.Data")

This was you can always keep a check of when it was run