X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;fp=doc%2Fstatistics.texi;h=6957b3836eae3a2c07f8bad2f64d30d781db1249;hb=4eac481a68b1be28ebcbdef2b38fc45dddd55c43;hp=c7abe4d88d4cb94a88a9e098913bdaa07656f486;hpb=f6491a00fd9755850740aa45530498b6ae5d265a;p=pspp

diff --git a/doc/statistics.texi b/doc/statistics.texi
index c7abe4d88d..6957b3836e 100644
--- a/doc/statistics.texi
+++ b/doc/statistics.texi
@@ -30,7 +30,6 @@ far.
 * ONEWAY::                      One way analysis of variance.
 * QUICK CLUSTER::               K-Means clustering.
 * RANK::                        Compute rank scores.
-* REGRESSION::                  Linear regression.
 * RELIABILITY::                 Reliability analysis.
 * ROC::                         Receiver Operating Characteristic.
 @end menu
@@ -514,9 +513,9 @@ The @cmd{GRAPH} command produces graphical plots of data. Only one of the subcom
 can be produced per call of @cmd{GRAPH}. The @subcmd{MISSING} is optional.
 
 @menu
-* SCATTERPLOT::             Cartesian Plots
-* HISTOGRAM::               Histograms
-* BAR CHART::               Bar Charts
+* SCATTERPLOT::                 Cartesian Plots
+* HISTOGRAM::                   Histograms
+* BAR CHART::                   Bar Charts
 @end menu
 
 @node SCATTERPLOT
@@ -987,16 +986,81 @@ previous @code{TABLE}.  All of these subcommands are optional:
     [@t{SHOWSIG=}@{@t{NO} @math{|} @t{YES}@}]
 @end display
 
-The @code{CTABLES} (aka ``custom tables'') command outputs
-multi-dimensional tables, offering many options for table
-summarization and formatting.
+The @code{CTABLES} (aka ``custom tables'') command produces
+multi-dimensional tables from categorical and scale data.  It offers
+many options for data summarization and formatting.
 
-@code{TABLE}, the only required subcommand, specifies the variables to
-include on each dimension, using the syntax @t{/TABLE} @i{rows} @t{BY}
-@i{columns} @t{BY} @i{layers}, in which @i{rows}, @i{columns}, and
-@i{layers} is each empty or an @i{axis}.  The simplest form of
-@i{axis} is just a variable name.  
+This section's examples use data from the 2008 (USA) National Survey
+of Drinking and Driving Attitudes and Behaviors, a public domain data
+set from the (USA) National Highway Traffic Administration and
+available at @url{https://data.transportation.gov}.  @pspp{} includes
+this data set, with a slightly modified dictionary, as
+@file{examples/nhtsa.sav}.
 
+@menu
+* CTABLES Basics::
+@end menu
+
+@node CTABLES Basics
+@subsection Basics
+
+The only required subcommand is @code{TABLE}, which specifies the
+variables to include along each axis:
+@display
+@t{/TABLE} @i{rows} [@t{BY} @i{columns} [@t{BY} @i{layers}]]
+@end display
+@noindent
+In @code{TABLE}, each of @var{rows}, @var{columns}, and @var{layers}
+is either empty or an axis expression that specifies one or more
+variables.  An axis expression that names a categorical variable
+divides the data into cells according to the values of that variable.
+When all the variables named on @code{TABLE} are categorical, by
+default each cell displays the number of cases that it contains, so
+specifying a single variable yields a frequency table:
+
+@example
+CTABLES /TABLE=AgeGroup.
+@end example
+@psppoutput {ctables1}
+
+@noindent
+Specifying a row and a column categorical variable yields a
+crosstabulation:
+
+@example
+CTABLES /TABLE=AgeGroup BY qns3a.
+@end example
+@psppoutput {ctables2}
+
+@noindent
+The @samp{>} operator nests multiple variables on a single axis, e.g.:
+
+@example
+CTABLES /TABLE qn105ba BY AgeGroup > qns3a.
+@end example
+@psppoutput {ctables3}
+
+@noindent
+The @samp{+} operator allows a single output table to include multiple
+data analyses.  With @samp{+}, @code{CTABLES} divides the output table
+into multiple sections, each of which includes an analysis of the full
+data set.  For example, the following command separately tabulates age
+group and driving frequency by gender:
+
+@example
+CTABLES /TABLE AgeGroup + qn1 BY qns3a.
+@end example
+@psppoutput {ctables4}
+
+@noindent
+If @samp{+} and @samp{>} are used together, @samp{>} binds more
+tightly.  Use parentheses to override operator precedence.  Thus:
+
+@example
+CTABLES /TABLE qn26 + qn27 > qns3a.
+CTABLES /TABLE (qn26 + qn27) > qns3a.
+@end example
+@psppoutput {ctables5}
 
 @node FACTOR
 @section FACTOR
@@ -1503,19 +1567,19 @@ is used.
 
 
 @menu
-* BINOMIAL::                Binomial Test
-* CHISQUARE::               Chi-square Test
-* COCHRAN::                 Cochran Q Test
-* FRIEDMAN::                Friedman Test
-* KENDALL::                 Kendall's W Test
-* KOLMOGOROV-SMIRNOV::      Kolmogorov Smirnov Test
-* KRUSKAL-WALLIS::          Kruskal-Wallis Test
-* MANN-WHITNEY::            Mann Whitney U Test
-* MCNEMAR::                 McNemar Test
-* MEDIAN::                  Median Test
-* RUNS::                    Runs Test
-* SIGN::                    The Sign Test
-* WILCOXON::                Wilcoxon Signed Ranks Test
+* BINOMIAL::                    Binomial Test
+* CHISQUARE::                   Chi-square Test
+* COCHRAN::                     Cochran Q Test
+* FRIEDMAN::                    Friedman Test
+* KENDALL::                     Kendall's W Test
+* KOLMOGOROV-SMIRNOV::          Kolmogorov Smirnov Test
+* KRUSKAL-WALLIS::              Kruskal-Wallis Test
+* MANN-WHITNEY::                Mann Whitney U Test
+* MCNEMAR::                     McNemar Test
+* MEDIAN::                      Median Test
+* RUNS::                        Runs Test
+* SIGN::                        The Sign Test
+* WILCOXON::                    Wilcoxon Signed Ranks Test
 @end menu