Subsetting das_dfr or das_df objects
Usage
# S3 method for das_dfr
[(x, i, j, ..., drop = TRUE)
# S3 method for das_dfr
$(x, name) <- value
# S3 method for das_dfr
[(x, i, j, ...) <- value
# S3 method for das_dfr
[[(x, i) <- value
# S3 method for das_df
[(x, i, j, ..., drop = TRUE)
# S3 method for das_df
$(x, name) <- value
# S3 method for das_df
[(x, i, j, ...) <- value
# S3 method for das_df
[[(x, i) <- valueArguments
- x
object of class
das_dfrordas_df- i, j, ...
elements to extract or replace, see
[.data.frame- drop
logical, see
[.data.frame- name
A literal character string or ..., see
[.data.frame- value
A suitable replacement value, see
[.data.frame
Details
When subsetting a das_dfr or das_df object, henceforth a das_ object,
using any of the functions described in [.data.frame,
then then the das_ class is simply dropped and the object is of class data.frame.
This is because of the strict format requirements of das_ objects;
it is likely that a subsetted das_ object will not have
the format required by subsequent swfscDAS functions,
and thus it is safest to drop the das_ class.
If a data frame is passed to downstream swfscDAS functions that require a das_ object,
then they will attempt to coerce the object to the necessary das_ class
See as_das_dfr and as_das_df for more details.
Examples
y <- system.file("das_sample.das", package = "swfscDAS")
y.read <- das_read(y)
# All return a data frame:
class(y.read[1:10, ])
#> [1] "data.frame"
class(y.read[, 1:10])
#> [1] "data.frame"
y.df <- y.read
y.df[, 1] <- "a"
class(y.df)
#> [1] "data.frame"
y.df <- y.read
y.df$Event <- "a"
class(y.df)
#> [1] "data.frame"
y.df <- y.read
y.df[["Event"]] <- "a"
class(y.df)
#> [1] "data.frame"