dumpObjects(..., list = character(0), dbName, type = NULL, envir = parent.frame())
dumpImage(dbName = "Rworkspace", type = NULL)
dumpDF(data, dbName = NULL, type = NULL)
dumpList(data, dbName = NULL, type = NULL)
dumpEnv(env, dbName)
Arguments
...
R objects to dump
list
character vector of names of objects to dump
dbName
character, name of database to which objects should be
dumped
type
type of database to create
envir
environment from which to obtain objects
data
a data frame or a list
env
an environment
Details
Objects dumped to a database can later be loaded via dbLoad or
can be accessed with dbFetch, dbList, etc.
Alternatively, the with method can be used to evaluate code in
the context of a database. If a database with name dbName
already exists, objects will be inserted into the existing database
(and values for already-existing keys will be overwritten).
dumpDF is different in that each variable in the data frame is
stored as a separate object in the database. So each variable can be
read from the database separately rather than having to load the
entire data frame into memory. dumpList works in a simlar
way.
The dumpEnv function takes an environment and stores each
element of the environment in a filehash database.
Value
An object of class "filehash" is returned and a database is
created.
Author(s)
Roger D. Peng
Examples
data <- data.frame(y = rnorm(100), x = rnorm(100), z = rnorm(100))
db <- dumpDF(data, dbName = "dataframe.dump")
fit <- with(db, lm(y ~ x + z))
summary(fit)
db <- dumpList(list(a = 1, b = 2, c = 3), "list.dump")
db$a