PSPP is a program for statistical analysis of sampled data. It
is a free replacement for the proprietary program SPSS.
PSPP development is ongoing. It already supports a large subset of
SPSS's syntax. Its statistical procedure support is currently
limited, but growing. At your option, PSPP will produce statistical
reports in ASCII, PostScript, or HTML formats.
Instructions for PSPP installation are in INSTALL, including a list of
prerequisite packages and other PSPP-specific information. Full
documentation on PSPP's language will be installed along with the
programs.
For information on differences from previous versions, please see file
NEWS.
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
at http://savannah.gnu.org/projects/pspp
The following miscellaneous notes apply to this release:
* On a few operating systems, such as OpenBSD, some of the
tests may fail with messages similar to: 'Warning: cannot
create a convertor for "646" to "UTF-8"'. These test
failures may safely be ignored.
Questions and comments about using PSPP may be sent to pspp-users@gnu.org.
Bug reports may be filed at http://savannah.gnu.org/bugs/?group=pspp
or emailed to bug-gnu-pspp@gnu.org. We prefer the web-based system
because it makes it more difficult for us to lose track of bugs, but we
are happy to hear from users through any means.
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.
* 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. This release
includes the first version of PSPPIRE, the PSPP graphical
user interface.
* 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. It has not been tuned
or extensively tested, however initial experience has given
impressive results.
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.
