X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=2cb79d23e49d7e7d81585cdabb2df944e0284d7e;hb=4dc2ebcfd1a113b25f6997ff3b66fa52ac41158b;hp=29e8f0646accf33ff418c65d9e5e13ef82fcdedf;hpb=1fc3af93c0ba6cbaf7ef09edc979096b6f16dd6f;p=pspp-builds.git diff --git a/doc/statistics.texi b/doc/statistics.texi index 29e8f064..2cb79d23 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -4,12 +4,17 @@ This chapter documents the statistical procedures that PSPP supports so far. +@c If you add any new commands, then don't forget to remove the entry in +@c not-implemented.texi + @menu * DESCRIPTIVES:: Descriptive statistics. * FREQUENCIES:: Frequency tables. +* EXAMINE:: Testing data for normality. * CROSSTABS:: Crosstabulation tables. * T-TEST:: Test hypotheses about means. -* ONEWAY:: One analysis of variance. +* ONEWAY:: One way analysis of variance. +* REGRESSION:: Linear regression. @end menu @node DESCRIPTIVES, FREQUENCIES, Statistics, Statistics @@ -102,7 +107,7 @@ in the order that they are specified on the VARIABLES subcommand. The A and D settings request an ascending or descending sort order, respectively. -@node FREQUENCIES, CROSSTABS, DESCRIPTIVES, Statistics +@node FREQUENCIES, EXAMINE, DESCRIPTIVES, Statistics @section FREQUENCIES @vindex FREQUENCIES @@ -209,7 +214,82 @@ boundaries of the data set divided into the specified number of ranges. For instance, @code{/NTILES=4} would cause quartiles to be reported. -@node CROSSTABS, T-TEST, FREQUENCIES, Statistics +@node EXAMINE, CROSSTABS, FREQUENCIES, Statistics +@comment node-name, next, previous, up +@section EXAMINE +@vindex EXAMINE + +@cindex Normality, testing for + +@display +EXAMINE + VARIABLES=var_list [BY factor_list ] + /STATISTICS=@{DESCRIPTIVES, EXTREME[(n)], ALL, NONE@} + /PLOT=@{STEMLEAF, BOXPLOT, NPPLOT, SPREADLEVEL(n), HISTOGRAM, + ALL, NONE@} + /CINTERVAL n + /COMPARE=@{GROUPS,VARIABLES@} + /ID=@{case_number, var_name@} + /@{TOTAL,NOTOTAL@} + /PERCENTILE=[value_list]=@{HAVERAGE, WAVERAGE, ROUND, AEMPIRICAL, EMPIRICAL @} + /MISSING=@{LISTWISE, PAIRWISE@} [@{EXCLUDE, INCLUDE@}] + [@{NOREPORT,REPORT@}] + +@end display + +The @cmd{EXAMINE} command is used to test how closely a distribution is to a +normal distribution. It also shows you outliers and extreme values. + +The VARIABLES subcommand specifies the dependent variables and the +independent variable to use as factors for the analysis. Variables +listed before the first BY keyword are the dependent variables. +The dependent variables may optionally be followed by a list of +factors which tell PSPP how to break down the analysis for each +dependent variable. The format for each factor is +@display +var [BY var]. +@end display + + +The STATISTICS subcommand specifies the analysis to be done. +DESCRIPTIVES will produce a table showing some parametric and +non-parametrics statistics. EXTREME produces a table showing extreme +values of the dependent variable. A number in parentheses determines +how many upper and lower extremes to show. The default number is 5. + + +The PLOT subcommand specifies which plots are to be produced if any. + +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 +/COMPARE=GROUPS is specified, then one plot per dependent variable is produced, +containing boxplots for all the factors. +If /COMPARE=VARIABLES is specified, then one plot per factor is produced, each +each containing one boxplot per dependent variable. +If the /COMPARE subcommand is ommitted, then PSPP uses the default value of +/COMPARE=GROUPS. + +The CINTERVAL subcommand specifies the confidence interval to use in +calculation of the descriptives command. The default it 95%. + +The PERCENTILES subcommand specifies which percentiles are to be calculated, +and which algorithm to use for calculating them. The default is to +calculate the 5, 10, 25, 50, 75, 90, 95 percentiles using the +HAVERAGE algorithm. + +The TOTAL and NOTOTAL subcommands are mutually exclusive. If NOTOTAL +is given and factors have been specified in the VARIABLES subcommand, +then then statistics for the unfactored dependent variables are +produced in addition to the factored variables. If there are no +factors specified then TOTAL and NOTOTAL have no effect. + +@strong{Warning!} +If many dependent variable are given, or factors are given for which +there are many distinct values, then @cmd{EXAMINE} will produce a very +large quantity of output. + + +@node CROSSTABS, T-TEST, EXAMINE, Statistics @section CROSSTABS @vindex CROSSTABS @@ -520,9 +600,9 @@ of variable preceding @code{WITH} against variable following @code{WITH} are generated. -@node ONEWAY, , T-TEST, Statistics +@node ONEWAY, REGRESSION, T-TEST, Statistics @comment node-name, next, previous, up -@section Oneway +@section ONEWAY @vindex ONEWAY @cindex analysis of variance @@ -569,3 +649,5 @@ display a warning, but will proceed with the analysis. The @code{CONTRASTS} subcommand may be given up to 10 times in order to specify different contrast tests. @setfilename ignored + +@include regression.texi