X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=89e5e83c56862dcf4dce5804d073ed7ae2652907;hb=502855f1d746c4acf920006326daa8c86a561a5b;hp=a67402c0e13bd178dc720078f5cf819ee829e160;hpb=65be63912fedc9819f76099b1ed52b189fc5fc03;p=pspp-builds.git diff --git a/doc/statistics.texi b/doc/statistics.texi index a67402c0..89e5e83c 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -506,6 +506,8 @@ NPAR TESTS [ /STATISTICS=@{DESCRIPTIVES@} ] [ /MISSING=@{ANALYSIS, LISTWISE@} @{INCLUDE, EXCLUDE@} ] + + [ /METHOD=EXACT [ TIMER [(n)] ] ] @end display NPAR TESTS performs nonparametric tests. @@ -515,10 +517,21 @@ One or more tests may be specified by using the corresponding subcommand. If the /STATISTICS subcommand is also specified, then summary statistics are produces for each variable that is the subject of any test. +Certain tests may take a long time to execute, if an exact figure is required. +Therefore, by default asymptotic approximations are used unless the +subcommand /METHOD=EXACT is specified. +Exact tests give more accurate results, but may take an unacceptably long +time to perform. If the TIMER keyword is used, it sets a maximum time, +after which the test will be abandoned, and a warning message printed. +The time, in minutes, should be specified in parentheses after the TIMER keyword. +If the TIMER keyword is given without this figure, then a default value of 5 minutes +is used. + @menu * BINOMIAL:: Binomial Test * CHISQUARE:: Chisquare Test +* WILCOXON:: Wilcoxon Signed Ranks Test @end menu @@ -598,6 +611,34 @@ sum of the frequencies need not be 1. If no /EXPECTED subcommand is given, then then equal frequencies are expected. +@node WILCOXON +@subsection Wilcoxon +@comment node-name, next, previous, up +@vindex WILCOXON +@cindex wilcoxon matched pairs signed ranks test + +@display + [ /WILCOXON varlist [ WITH varlist [ (PAIRED) ]]] +@end display + +The wilcoxon subcommand tests for differences between means of the +variables listed. The test does not make any assumptions about the +variances of the samples. + +If the @code{WITH} keyword is omitted, then tests for all +combinations of the listed variables are performed. +If the @code{WITH} keyword is given, and the @code{(PAIRED)} keyword +is also given, then the number of variables preceding @code{WITH} +must be the same as the number following it. +In this case, tests for each respective pair of variables are +performed. +If the @code{WITH} keyword is given, but the +@code{(PAIRED)} keyword is omitted, then tests for each combination +of variable preceding @code{WITH} against variable following +@code{WITH} are performed. + +If the number of observations is large, and exact tests have been +requested. then the test may take a very long time to complete. @node T-TEST @comment node-name, next, previous, up