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