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Write and read CSV files in Prova

Source: R/util_datafiles.R
prova.data.Rd

Utility functions to read and write CSV files in the format required by Prova

Usage

pwrite.csv(x, file, ...)

pread.csv(file, ...)

Arguments

x

The object to be written. Preferably a matrix or data frame; if not, it is attempted to coerce x to a data frame. See utils::write.csv().

file

Either a character naming a file or a connection open for writing or reading. See utils::write.csv() and utils::read.csv().

...

Other arguments to be passed to utils::write.csv() or utils::read.csv(). Arguments 'row.names', 'quote', 'na', 'na.strings', 'tryLogical', 'sep', 'dec' are not allowed.

Value

pread.csv returns a data frame containing a representation of the data in the file; see utils::read.csv(). pwrite.csv' returns NULL` invisibly.

Details

The functions learn() and metadatatemplate() accept CSV files formatted as follows:

  • Decimal values should be separated by a dot; no comma should be used to separate thousands etc. Example: 86342.75.

  • Character and names should be quoted in single or double quotes. Example: "female".

  • Values should be separated by commas, not by tabs or semicolons.

  • Missing values should be simply empty, not denoted by "NA", "missing", "-", or similar.

  • Preferably there should not be factors (see base::factor); use character names instead.

The utility functions pwrite.csv() and pread.csv() are wrappers to utils::write.csv() and utils::read.csv() that set appropriate default parameters according to the formatting rules above.

See also

metadatatemplate() to help writing metadata files.

learn(), which needs a metadata data-frame or CSV file.

Examples

## Save the 'penguins' dataset in a (temporary) file
filename <- tempfile(fileext = '.csv')

pwrite.csv(penguins, file = filename)

## check first few lines of the raw file
writeLines(readLines(filename, n = 10))
#> "species","island","bill_len","bill_dep","flipper_len","body_mass","sex","year"
#> "Adelie","Torgersen",39.1,18.7,181,3750,"male",2007
#> "Adelie","Torgersen",39.5,17.4,186,3800,"female",2007
#> "Adelie","Torgersen",40.3,18,195,3250,"female",2007
#> "Adelie","Torgersen",,,,,,2007
#> "Adelie","Torgersen",36.7,19.3,193,3450,"female",2007
#> "Adelie","Torgersen",39.3,20.6,190,3650,"male",2007
#> "Adelie","Torgersen",38.9,17.8,181,3625,"female",2007
#> "Adelie","Torgersen",39.2,19.6,195,4675,"male",2007
#> "Adelie","Torgersen",34.1,18.1,193,3475,,2007