Thursday, January 19, 2012

What kind of data formats does SAMHDA distribute? Do you have SPSS portable files? SAS transport? Stata?

SAMHDA distributes data files in the following formats: SAS, SPSS, Stata, ASCII, tab-delimited, and R. ASCII data files can be downloaded with their accompanying SAS, SPSS, or Stata setup files.

SAS

SAS transport files are generated by the SAS XPORT (for studies with older release dates) and SAS CPORT (for studies with newer release dates) procedures. Both types of files contain specially formatted SAS data sets, which have variable labels as well as data. SAMHDA's SAS CPORT files include SAS format catalogs with value labels. SAMHDA also supplies a SAS supplemental syntax file that provides missing value recodes.

SAS CPORT files should be imported into SAS with the SAS CIMPORT procedure. See the FAQ "What is a SAS CPORT file? How do I use it?" for additional information.

Since SAS has an engine that reads SAS XPORT files, they can be read by any SAS command that can read an ordinary SAS data set, such as the SAS set statement or the SAS FREQ procedure. SAS XPORT files can also be converted to standard SAS data sets with the SAS COPY procedure.

SPSS

SAMHDA distributes two types of SPSS data files: SPSS SAV files written by the SPSS save command and SPSS portable files written by the SPSS export command. Both types of data files include variable labels and usually include value labels and missing value definitions.

To load SPSS SAV files into SPSS use the SPSS get command.

To read SPSS portable files into SPSS use the SPSS import command.

Stata

Stata data files should be loaded into Stata with the Stata use command.

R

To load R .rda files into R, use the R load () command. For example, if your downloaded data file, 32722-0001-Data.rda, is located at d:/Downloads/ICPSR_32722/DS0001, use load("d:/Downloads/ICPSR_32722/DS0001/32722-0001-Data.rda").

Using ASCII data and setup files

ICPSR has prepared tutorials on how to use setup files to import ASCII data:

  • ASCII Data File + SAS Setup Files : PDF PPT
  • ASCII Data File + SPSS Setup Files : PDF PPT
  • ASCII Data File + Stata Setup Files : PDF PPT

SAMHDA also offers the following help resources related to using specific data formats:

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