X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=doc%2Fstatistics.texi;h=36727c44c5f75dfa7620e900029875d4c2dd874b;hb=93a7decc9a02886e5852ecf37ef820665ec798d3;hp=18fa79ac5209956065e069ddb7505f0537a4c8f2;hpb=7acdff072470c7e87ac9ba7c2f135e4c08fd0e02;p=pspp-builds.git diff --git a/doc/statistics.texi b/doc/statistics.texi index 18fa79ac..36727c44 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -14,6 +14,7 @@ far. * NPAR TESTS:: Nonparametric tests. * T-TEST:: Test hypotheses about means. * ONEWAY:: One way analysis of variance. +* QUICK CLUSTER:: K-Means clustering. * RANK:: Compute rank scores. * REGRESSION:: Linear regression. * RELIABILITY:: Reliability analysis. @@ -1101,7 +1102,7 @@ ONEWAY /MISSING=@{ANALYSIS,LISTWISE@} @{EXCLUDE,INCLUDE@} /CONTRAST= value1 [, value2] ... [,valueN] /STATISTICS=@{DESCRIPTIVES,HOMOGENEITY@} - + /POSTHOC=@{BONFERRONI, GH, LSD, SCHEFFE, SIDAK, TUKEY, ALPHA ([value])@} @end display The @cmd{ONEWAY} procedure performs a one-way analysis of variance of @@ -1145,11 +1146,76 @@ 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. +Using the @code{POSTHOC} subcommand you can perform multiple +pairwise comparisons on the data. The following comparison methods +are available: +@itemize +@item LSD +Least Significant Difference. +@item TUKEY +Tukey Honestly Significant Difference. +@item BONFERRONI +Bonferroni test. +@item SCHEFFE +Scheff@'e's test. +@item SIDAK +Sidak test. +@item GH +The Games-Howell test. +@end itemize + +@noindent +The optional syntax @code{ALPHA(@var{value})} is used to indicate +that @var{value} should be used as the +confidence level for which the posthoc tests will be performed. +The default is 0.05. + +@node QUICK CLUSTER +@comment node-name, next, previous, up +@section QUICK CLUSTER +@vindex QUICK CLUSTER + +@cindex K-means clustering +@cindex clustering + +@display +QUICK CLUSTER var_list + [/CRITERIA=CLUSTERS(@var{k}) [MXITER(@var{max_iter})]] + [/MISSING=@{EXCLUDE,INCLUDE@} @{LISTWISE, PAIRWISE@}] +@end display + +The @cmd{QUICK CLUSTER} command performs k-means clustering on the +dataset. This is useful when you wish to allocate cases into clusters +of similar values and you already know the number of clusters. + +The minimum specification is @samp{QUICK CLUSTER} followed by the names +of the variables which contain the cluster data. Normally you will also +want to specify @samp{/CRITERIA=CLUSTERS(@var{k})} where @var{k} is the +number of clusters. If this is not given, then @var{k} defaults to 2. + +The command uses an iterative algorithm to determine the clusters for +each case. It will continue iterating until convergence, or until @var{max_iter} +iterations have been done. The default value of @var{max_iter} is 2. + +The @cmd{MISSING} subcommand determines the handling of missing variables. +If INCLUDE is set, then user-missing values are considered at their face +value and not as missing values. +If EXCLUDE is set, which is the default, user-missing +values are excluded as well as system-missing values. + +If LISTWISE is set, then the entire case is excluded from the analysis +whenever any of the clustering variables contains a missing value. +If PAIRWISE is set, then a case is considered missing only if all the +clustering variables contain missing values. Otherwise it is clustered +on the basis of the non-missing values. +The default is LISTWISE. + @node RANK @comment node-name, next, previous, up @section RANK + @vindex RANK @display RANK