Rediger

Del via

rxCompressXdf: Compress .xdf files

  • Artikkel

Description

Compress one or more .xdf files

Usage

  rxCompressXdf(inFile, outFile = NULL, xdfCompressionLevel = 1, overwrite = FALSE, reportProgress = rxGetOption("reportProgress"))

Arguments

inFile

An .xdf file name, an RxXdfData data source, a directory containing .xdf files, or a vector of .xdf file names or RxXdfData data sources to compress

outFile

An .xdf file name, an RxXdfData data source, a directory, or a vector of .xdf file names or RxXdfData data sources to contain the compressed files.

xdfCompressionLevel

integer in the range of -1 to 9. The higher the value, the greater the amount of compression - resulting in smaller files but a longer time to create them. If xdfCompressionLevel is set to 0, there will be no compression and files will be compatible with the 6.0 release of Revolution R Enterprise. If set to -1, a default level of compression will be used.

overwrite

If outFile is specified and is different from inFile, overwrite must be set to TRUE to have outFile overwritten.

reportProgress

integer value with options:

  • 0: no progress is reported.
  • 1: the number of processed rows is printed and updated.
  • 2: rows processed and timings are reported.
  • 3: rows processed and all timings are reported.

Details

rxCompressXdf uses ZLIB to compress .xdf files in blocks. The auto compression level of -1 is equivalent to approximately 6. Typically setting the xdfCompressionLevel to 1 will provide an adequate amount of compression at the fastest speed.

Value

A vector of RxXdfData data sources

Author(s)

Microsoft Corporation Microsoft Technical Support

See Also

rxImport, rxDataStep, RxXdfData,

Examples



 # Get location of sample uncompressed .xdf file
 sampleXdf <- file.path(rxGetOption("sampleDataDir"), "AirlineDemoSmallUC.xdf")

 # Create name for a temporary file
 compressXdf <- tempfile(pattern = ".rxCompress", fileext = ".xdf")    

 # Create a new compressed .xdf file from the sample file
 newDS <- rxCompressXdf(inFile = sampleXdf, outFile = compressXdf, xdfCompressionLevel = 1)

 # Get information about files and compare sizes
 sampleFileInfo <- file.info(sampleXdf)
 compressFileInfo <- file.info(compressXdf)
 sampleFileInfo$size
 compressFileInfo$size

 # Clean-up
 file.remove(compressXdf)