Docment how CLABELS can affect calculations.

[pspp] / doc / statistics.texi

diff --git a/doc/statistics.texi b/doc/statistics.texi
index 7ac4191bb880d5b90d63c23bc99aa671af211ef9..2e133dd651ad3ded4525ef91f655ba6c1abd1344 100644 (file)
--- a/doc/statistics.texi
+++ b/doc/statistics.texi
@@ -1500,6 +1500,33 @@ column variable category labels, respectively, to the layer axis.
 Only one axis's labels may be moved, whether to the opposite axis or
 to the layer axis.
 
+@subsubheading Effect on Summary Statistics
+
+@code{CLABELS} primarily affects the appearance of tables, not the
+data displayed in them.  However, @code{CTABLES} can affect the values
+displayed for statistics that summarize areas of a table, since it can
+change the definitions of these areas.
+
+For example, consider the following syntax and output:
+
+@example
+CTABLES /TABLE AgeGroup BY qns3a [ROWPCT, COLPCT].
+@end example
+@psppoutput {ctables23}
+
+@noindent
+Using @code{COLLABELS=OPPOSITE} changes the definitions of rows and
+columns, so that column percentages display what were previously row
+percentages and the new row percentages become meaningless (because
+there is only one cell per row):
+
+@example
+CTABLES
+    /TABLE AgeGroup BY qns3a [ROWPCT, COLPCT]
+    /CLABELS COLLABELS=OPPOSITE.
+@end example
+@psppoutput {ctables24}
+
 @node CTABLES Per-Variable Category Options
 @subsection Per-Variable Category Options