matter_fc-class {matter} | R Documentation |
The matter_fc
class implements on-disk factors.
## Instance creation matter_fc(data, datamode = "int", paths = NULL, filemode = ifelse(all(file.exists(paths)), "rb", "rb+"), offset = 0, extent = length, length = 0L, names = NULL, levels = base::levels(as.factor(data)), ...) ## Additional methods documented below
data |
An optional data vector which will be initially written to the data on disk if provided. |
datamode |
Must be an integral type for factors. |
paths |
A 'character' vector of the paths to the files where the data are stored. If 'NULL', then a temporary file is created using |
filemode |
The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access. |
offset |
A vector giving the offsets in number of bytes from the beginning of each file in 'paths', specifying the start of the data to be accessed for each file. |
extent |
A vector giving the length of the data for each file in 'paths', specifying the number of elements of size 'datamode' to be accessed from each file. |
length |
An optional number giving the total length of the data across all files, equal to the sum of 'extent'. This is ignored and calculated automatically if 'extent' is specified. |
names |
The names of the data elements. |
levels |
The levels of the factor. |
... |
Additional arguments to be passed to constructor. |
An object of class matter_fc
.
data
:This slot stores the information about locations of the data on disk and within the files.
datamode
:The storage mode of the accessed data when read into R. This is a 'character' vector of length one with value 'integer' or 'numeric'.
paths
:A 'character' vector of the paths to the files where the data are stored.
filemode
:The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access.
chunksize
:The maximum number of elements which should be loaded into memory at once. Used by methods implementing summary statistics and linear algebra. Ignored when explicitly subsetting the dataset.
length
:The length of the data.
dim
:Either 'NULL' for vectors, or an integer vector of length one of more giving the maximal indices in each dimension for matrices and arrays.
names
:The names of the data elements for vectors.
dimnames
:Either 'NULL' or the names for the dimensions. If not 'NULL', then this should be a list of character vectors of the length given by 'dim' for each dimension. This is always 'NULL' for vectors.
ops
:Delayed operations to be applied on atoms.
levels
:The levels of the factor.
matter_fc
instances can be created through matter_fc()
or matter()
.
Standard generic methods:
x[i], x[i] <- value
:Get or set the elements of the factor.
levels(x), levels(x) <- value
:Get or set the levels of the factor.
Kylie A. Bemis
x <- matter_fc(c("a", "a", "b"), levels=c("a", "b", "c")) x[]