PSPP is a program for statistical analysis of sampled data. It
interprets commands in the SPSS language and produces tabular output
in ASCII, PostScript, or HTML format.
PSPP development is ongoing. It already supports a large subset of
SPSS's transformation language. Its statistical procedure support is
currently limited, but growing.
For information on differences from previous versions, please see file
NEWS. Full documentation on PSPP's language can be found in the doc/
directory.
Source code for the latest release of PSPP is available at
ftp://ftp.gnu.org/pub/gnu/pspp/. Older versions may be obtained from
ftp://alpha.gnu.org/gnu/pspp/. Development sources are available from
CVS at http://savannah.gnu.org/projects/pspp
Questions and comments regarding PSPP can be sent to pspp-dev@gnu.org.
PSPP bug reports may be sent to bug-gnu-pspp@gnu.org or filed in the
bug-tracking system at http://savannah.gnu.org/bugs/?group=pspp
according to your preference.
The long term goals for PSPP are ambitious. We wish to provide the
following support to users:
* All of the SPSS transformation language. PSPP already
supports a large subset of it.
* All the statistical procedures that someone is willing to
implement, whether they exist in SPSS or not. Currently,
statistical support is limited, but growing.
* Compatibility with SPSS syntax, including compatibility with
known bugs and warts, where it makes sense. We also provide
an "enhanced" mode in certain cases where PSPP can output
better results that may surprise SPSS users.
* Friendly textual and graphical interfaces. PSPP does not do
a good job of this yet.
* Attractive output, including graphs, in a variety of human-
and machine-readable formats. PSPP currently produces
output in ASCII, PostScript, and HTML formats. We will
enhance PSPP's output formatting in the future.
* Good documentation. Currently the PSPP manual describes its
language completely, but we would like to add information on
how to select statistical procedures and interpret their
results.
* Efficient support for very large data sets. For procedures
where it is practical, we wish to efficiently support data
sets many times larger than physical memory. The framework
for this feature is already in place, but it has not been
tuned or extensively tested.
Over the long term, we also wish to provide support to developers who
wish to extend PSPP with new statistical procedures, by supplying the
following:
* Easy-to-use support for parsing language syntax. Currently,
parsing is done by writing "recursive descent" code by hand,
with some support for automated parsing of the most common
constructs. We wish to improve the situation by supplying a
more complete and flexible parser generator.
* Easy-to-use support for producing attractive output.
Currently, output is done by writing code to explicitly fill
in table cells with data. We should be able to supply a
more convenient interface that also allows for providing
machine-readable output.
* Eventually, a plug-in interface for procedures. Over the
short term, the interface between the PSPP core and
statistical procedures is evolving quickly enough that a
plug-in model does not make sense. Over the long term, it
may make sense to introduce plug-ins.