Dump objects of database
Dump R objects to a filehash database
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)
... |
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 |
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.
An object of class "filehash" is returned and a database is
created.
Roger D. Peng
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
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