-@section SPSS Viewer Format
@node SPSS Viewer Format
+@section SPSS Viewer Format
SPSS Viewer or @file{.spv} files, here called SPV files, are written
by SPSS 16 and later to represent the contents of its output editor.
enough to read SPV files, but it is probably not sufficient to
write them.
+An an aside, SPSS 15 and earlier versions use a completely different
+output format based on the Microsoft Compound Document Format. This
+format is not documented.
+
An SPV file is a Zip archive that can be read with @command{zipinfo}
and @command{unzip} and similar programs. The final member in the Zip
archive is a file named @file{META-INF/MANIFEST.MF}. This structure
manifest contains a sequence of colon-delimited key/value pairs, an
SPV manifest contains the string @samp{allowPivoting=true}, without a
new-line.
+
+The rest of the members in an SPV file's Zip archive fall into two
+categories: structure and details. ``Structure'' member names begin
+with @file{outputViewer@var{nnnnnnnnnn}}, where each @var{n} is a
+decimal digit, and end with @file{.xml}, and often include the string
+@file{_heading} in between. Each of these members represents some
+kind of output item (a table, a heading, a block of text, etc.) or a
+group of them. The member whose output goes at the beginning of the
+document is numbered 0, the next member in the output is numbered 1,
+and so on.
+
+Structure members contain XML. This XML is sometimes self-contained,
+but it often references other members in the Zip archive named as
+follows:
+
+@table @asis
+@item @file{@var{prefix}_table.xml} and @file{@var{prefix}_tableData.bin}
+@itemx @file{@var{prefix}_lightTableData.bin}
+The structure of a table plus its data. Older SPV files pair a
+@file{@var{prefix}_table.xml} file that describes the table's
+structure with a binary @file{@var{prefix}_tableData.bin} file that
+gives its data. Newer SPV files (the majority of those in the corpus)
+instead include a single @file{@var{prefix}_lightTableData.bin} file
+that incorporates both into a single binary format.
+
+@item @file{@var{prefix}_warning.xml} and @file{@var{prefix}_warningData.bin}
+@itemx @file{@var{prefix}_lightWarningData.bin}
+Same format used for tables, with a different name.
+
+@item @file{@var{prefix}_notes.xml} and @file{@var{prefix}_notesData.bin}
+@itemx @file{@var{prefix}_lightNotesData.bin}
+Same format used for tables, with a different name.
+
+@item @file{@var{prefix}_chartData.bin} and @file{@var{prefix}_chart.xml}
+The structure of a chart plus its data. Charts do not have a
+``light'' format.
+
+@item @var{prefix}_model.xml
+@itemx @var{prefix}_pmml.xml
+@itemx @var{prefix}_stats.xml
+Not yet investigated. The corpus contains only one example of each.
+@end table
+
+The @file{@var{prefix}} in the names of the detail members is
+typically an 11-digit decimal number that increases for each item,
+tending to skip values. Older SPV files use different naming
+conventions. Structure member refer to detail members by name, and so
+their exact names do not appear to matter as long as they are unique.
+
+@node SPV Structure Member Format
+@subsection Structure Member Format
+
+Structure members XML files claim conformance with a collection of XML
+Schemas. These schemas are distributed, under a nonfree license, with
+SPSS binaries. Fortunately, the schemas are not necessary to
+understand the structure members. To a degree, the schemas can even
+be deceptive because they document elements and attributes that are
+not in the corpus and lack documentation of elements and attributes
+that are commonly found in the corpus.
+
+Structure members use a different XML namespace for each schema, but
+these namespaces are not entirely consistent: in some SPV files, for
+example, the @code{viewer-tree} schema is associated with namespace
+@indicateurl{http://xml.spss.com/spss/viewer-tree} and in other with
+@indicateurl{http://xml.spss.com/spss/viewer/viewer-tree} (note the
+additional @file{viewer/} directory. In any case, the schema URIs are
+not resolvable to obtain the schemas themselves.
+
+One may ignore all of the above in interpreting a structure member.
+The actual XML has a simple and straightforward form that does not
+require a reader to take schemas or namespaces into account. The
projects / pspp / blobdiff