Read several data sets

Reads a text file in table format and creates a matrix from it. The file may contain several sets, separated by empty lines. Lines starting by '#' are considered comments and treated as empty lines. The function adds an additional column set to indicate to which set each row belongs.

Usage

read_datasets(file, col_names, text)

Arguments

file: character()
Filename that contains the data. Each row of the table appears as one line of the file. If it does not contain an absolute path, the file name is relative to the current working directory, base::getwd(). Tilde-expansion is performed where supported. Files compressed with xz are supported.
col_names: character()
Vector of optional names for the variables. The default is to use "V" followed by the column number.
text: character()
If file is not supplied and this is, then data are read from the value of text via a text connection. Notice that a literal string can be used to include (small) data sets within R code.

Value

matrix()
A numerical matrix of the data in the file. An extra column set is added to indicate to which set each row belongs.

Note

There are several examples of data sets in system.file(package="moocore","extdata").

Warning

A known limitation is that the input file must use newline characters native to the host system, otherwise they will be, possibly silently, misinterpreted. In GNU/Linux the program dos2unix may be used to fix newline characters.

Author

Manuel López-Ibáñez

Examples

extdata_path <- system.file(package="moocore","extdata")
A1 <- read_datasets(file.path(extdata_path,"ALG_1_dat.xz"))
str(A1)
#>  num [1:23260, 1:3] 1.23e+10 1.11e+10 1.18e+10 1.13e+10 9.80e+09 ...
#>  - attr(*, "dimnames")=List of 2
#>   ..$ : NULL
#>   ..$ : chr [1:3] "V1" "V2" "set"

read_datasets(text="1 2\n3 4\n\n5 6\n7 8\n", col_names=c("obj1", "obj2"))
#>      obj1 obj2 set
#> [1,]    1    2   1
#> [2,]    3    4   1
#> [3,]    5    6   2
#> [4,]    7    8   2