Add documentation for the Kruskal-Wallis subcommand

[pspp-builds.git] / doc / statistics.texi

diff --git a/doc/statistics.texi b/doc/statistics.texi
index 81e16698c85c6cd63242c3849bc35fe5db6c828d..be696009e4249ddc1f80eded72921e08e4b51502 100644 (file)
--- a/doc/statistics.texi
+++ b/doc/statistics.texi
@@ -183,6 +183,7 @@ The NTILES subcommand causes the percentiles to be reported at the
 boundaries of the data set divided into the specified number of ranges.
 For instance, @code{/NTILES=4} would cause quartiles to be reported.
 
+@cindex histogram
 The HISTOGRAM subcommand causes the output to include a histogram for
 each specified numeric variable.  The X axis by default ranges from
 the minimum to the maximum value observed in the data, but the MINIMUM
@@ -190,6 +191,7 @@ and MAXIMUM keywords can set an explicit range.  Specify NORMAL to
 superimpose a normal curve on the histogram.  Histograms are not
 created for string variables.
 
+@cindex piechart
 The PIECHART adds a pie chart for each variable to the data.  Each
 slice represents one value, with the size of the slice proportional to
 the value's frequency.  By default, all non-missing values are given
@@ -243,7 +245,11 @@ values of the dependent variable.  A number in parentheses determines
 how many upper and lower extremes to show.  The default number is 5.
 
 
+@cindex boxplot
+@cindex histogram
+@cindex npplot
 The PLOT subcommand specifies which plots are to be produced if any.
+Available plots are HISTOGRAM, NPPLOT and BOXPLOT.
 
 The COMPARE subcommand is only relevant if producing boxplots, and it is only 
 useful there is more than one dependent variable and at least one factor.   If 
@@ -675,6 +681,7 @@ is used.
 @menu
 * BINOMIAL::                Binomial Test
 * CHISQUARE::               Chisquare Test
+* KRUSKAL-WALLIS::          Kruskal-Wallis Test
 * WILCOXON::                Wilcoxon Signed Ranks Test
 * SIGN::                    The Sign Test
 @end menu
@@ -756,6 +763,32 @@ sum of the frequencies need not be 1.
 If no /EXPECTED subcommand is given, then then equal frequencies 
 are expected.
 
+
+@node KRUSKAL-WALLIS
+@subsection Kruskal-Wallis Test
+@comment  node-name,  next,  previous,  up
+@vindex KRUSKAL-WALLIS
+@vindex K-W
+@cindex Kruskal-Wallis test
+
+@display
+     [ /KRUSKAL-WALLIS = varlist BY var (lower, upper) ]
+@end display
+
+The Kruskal-Wallis test is used to compare data from an 
+arbitrary number of populations.  It does not assume normality.
+The data to be compared are specified by @var{varlist}.
+The categorical variable determining the groups to which the
+data belongs is given by @var{var}. The limits @var{lower} and
+@var{upper} specify the valid range of @var{var}. Any cases for
+which @var{var} falls outside [@var{lower}, @var{upper}] will be
+ignored.
+
+The mean rank of each group as well as the chi-squared value and significance
+of the test will be printed.
+The abbreviated subcommand  K-W may be used in place of KRUSKAL-WALLIS.
+
+
 @node WILCOXON
 @subsection Wilcoxon Matched Pairs Signed Ranks Test
 @comment  node-name,  next,  previous,  up
@@ -958,7 +991,7 @@ variables factored by a single independent variable.
 It is used to compare the means of a population
 divided into more than two groups. 
 
-The  variables to be analysed should be given in the @code{VARIABLES}
+The dependent variables to be analysed should be given in the @code{VARIABLES}
 subcommand.  
 The list of variables must be followed by the @code{BY} keyword and
 the name of the independent (or factor) variable.
@@ -984,6 +1017,16 @@ If the total sum of the coefficients are not zero, then PSPP will
 display a warning, but will proceed with the analysis.
 The @code{CONTRAST} subcommand may be given up to 10 times in order
 to specify different contrast tests.
+The @code{MISSING} subcommand defines how missing values are handled.
+If LISTWISE is specified then cases which have missing values for 
+the independent variable or any dependent variable will be ignored.
+If ANALYSIS is specified, then cases will be ignored if the independent
+variable is missing or if the dependent variable currently being 
+analysed is missing.  The default is ANALYSIS.
+A setting of EXCLUDE means that variables whose values are
+user-missing are to be excluded from the analysis. A setting of
+INCLUDE means they are to be included.  The default is EXCLUDE.
+
 
 @node RANK
 @comment  node-name,  next,  previous,  up