X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=44db27aad129f0585f8027c1ad88df8a2e5a319d;hb=516498aeacfb469b79a2fa411553fbc11766a7fc;hp=c0e6a1c084d190fdad0a055bec2517d0c034228f;hpb=0e958ac80f5add8d0581c218badbdf9bddcde9bc;p=pspp diff --git a/doc/statistics.texi b/doc/statistics.texi index c0e6a1c084..44db27aad1 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -20,6 +20,7 @@ far. * GRAPH:: Plot data. * CORRELATIONS:: Correlation tables. * CROSSTABS:: Crosstabulation tables. +* CTABLES:: Custom tables. * FACTOR:: Factor analysis and Principal Components analysis. * GLM:: Univariate Linear Models. * LOGISTIC REGRESSION:: Bivariate Logistic Regression. @@ -29,7 +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 @@ -678,12 +678,8 @@ The keyword @subcmd{ALL} is the union of @subcmd{DESCRIPTIVES} and @subcmd{XPROD CROSSTABS /TABLES=@var{var_list} BY @var{var_list} [BY @var{var_list}]@dots{} /MISSING=@{TABLE,INCLUDE,REPORT@} - /WRITE=@{NONE,CELLS,ALL@} /FORMAT=@{TABLES,NOTABLES@} - @{PIVOT,NOPIVOT@} @{AVALUE,DVALUE@} - @{NOINDEX,INDEX@} - @{BOX,NOBOX@} /CELLS=@{COUNT,ROW,COLUMN,TOTAL,EXPECTED,RESIDUAL,SRESIDUAL, ASRESIDUAL,ALL,NONE@} /COUNT=@{ASIS,CASE,CELL@} @@ -728,8 +724,6 @@ tables and statistics. When set to @subcmd{REPORT}, which is allowed only in integer mode, user-missing values are included in tables but marked with a footnote and excluded from statistical calculations. -Currently the @subcmd{WRITE} subcommand is ignored. - The @subcmd{FORMAT} subcommand controls the characteristics of the crosstabulation tables to be displayed. It has a number of possible settings: @@ -737,22 +731,11 @@ settings: @itemize @w{} @item @subcmd{TABLES}, the default, causes crosstabulation tables to be output. -@subcmd{NOTABLES} suppresses them. - -@item -@subcmd{PIVOT}, the default, causes each @subcmd{TABLES} subcommand to be displayed in a -pivot table format. @subcmd{NOPIVOT} causes the old-style crosstabulation format -to be used. +@subcmd{NOTABLES}, which is equivalent to @code{CELLS=NONE}, suppresses them. @item @subcmd{AVALUE}, the default, causes values to be sorted in ascending order. @subcmd{DVALUE} asserts a descending sort order. - -@item -@subcmd{INDEX} and @subcmd{NOINDEX} are currently ignored. - -@item -@subcmd{BOX} and @subcmd{NOBOX} is currently ignored. @end itemize The @subcmd{CELLS} subcommand controls the contents of each cell in the displayed @@ -862,6 +845,1137 @@ Approximate T is not calculated for symmetric uncertainty coefficient. Fixes for any of these deficiencies would be welcomed. +@subsection Crosstabs Example + +@cindex chi-square test of independence + +A researcher wishes to know if, in an industry, a person's sex is related to +the person's occupation. To investigate this, she has determined that the +@file{personnel.sav} is a representative, randomly selected sample of persons. +The researcher's null hypothesis is that a person's sex has no relation to a +person's occupation. She uses a chi-squared test of independence to investigate +the hypothesis. + +@float Example, crosstabs:ex +@psppsyntax {crosstabs.sps} +@caption {Running crosstabs on the @exvar{sex} and @exvar{occupation} variables} +@end float + +The syntax in @ref{crosstabs:ex} conducts a chi-squared test of independence. +The line @code{/tables = occupation by sex} indicates that @exvar{occupation} +and @exvar{sex} are the variables to be tabulated. To do this using the @gui{} +you must place these variable names respectively in the @samp{Row} and +@samp{Column} fields as shown in @ref{crosstabs:scr}. + +@float Screenshot, crosstabs:scr +@psppimage {crosstabs} +@caption {The Crosstabs dialog box with the @exvar{sex} and @exvar{occupation} variables selected} +@end float + +Similarly, the @samp{Cells} button shows a dialog box to select the @code{count} +and @code{expected} options. All other cell options can be deselected for this +test. + +You would use the @samp{Format} and @samp{Statistics} buttons to select options +for the @subcmd{FORMAT} and @subcmd{STATISTICS} subcommands. In this example, +the @samp{Statistics} requires only the @samp{Chisq} option to be checked. All +other options should be unchecked. No special settings are required from the +@samp{Format} dialog. + +As shown in @ref{crosstabs:res} @cmd{CROSSTABS} generates a contingency table +containing the observed count and the expected count of each sex and each +occupation. The expected count is the count which would be observed if the +null hypothesis were true. + +The significance of the Pearson Chi-Square value is very much larger than the +normally accepted value of 0.05 and so one cannot reject the null hypothesis. +Thus the researcher must conclude that a person's sex has no relation to the +person's occupation. + +@float Results, crosstabs:res +@psppoutput {crosstabs} +@caption {The results of a test of independence between @exvar{sex} and @exvar{occupation}} +@end float + +@node CTABLES +@section CTABLES + +@vindex CTABLES +@cindex custom tables +@cindex tables, custom + +@code{CTABLES} has the following overall syntax. At least one +@code{TABLE} subcommand is required: + +@display +@t{CTABLES} + @dots{}@i{global subcommands}@dots{} + [@t{/TABLE} @i{axis} [@t{BY} @i{axis} [@t{BY} @i{axis}]] + @dots{}@i{per-table subcommands}@dots{}]@dots{} +@end display + +@noindent +where each @i{axis} may be empty or take one of the following forms: + +@display +@i{variable} +@i{variable} @t{[}@{@t{C} @math{|} @t{S}@}@t{]} +@i{axis} + @i{axis} +@i{axis} > @i{axis} +(@i{axis}) +@i{axis} @t{[}@i{summary} [@i{string}] [@i{format}]@t{]} +@end display + +The following subcommands precede the first @code{TABLE} subcommand +and apply to all of the output tables. All of these subcommands are +optional: + +@display +@t{/FORMAT} + [@t{MINCOLWIDTH=}@{@t{DEFAULT} @math{|} @i{width}@}] + [@t{MAXCOLWIDTH=}@{@t{DEFAULT} @math{|} @i{width}@}] + [@t{UNITS=}@{@t{POINTS} @math{|} @t{INCHES} @math{|} @t{CM}@}] + [@t{EMPTY=}@{@t{ZERO} @math{|} @t{BLANK} @math{|} @i{string}@}] + [@t{MISSING=}@i{string}] +@t{/VLABELS} + @t{VARIABLES=}@i{variables} + @t{DISPLAY}=@{@t{DEFAULT} @math{|} @t{NAME} @math{|} @t{LABEL} @math{|} @t{BOTH} @math{|} @t{NONE}@} +@ignore @c not yet implemented +@t{/MRSETS COUNTDUPLICATES=}@{@t{YES} @math{|} @t{NO}@} +@end ignore +@t{/SMISSING} @{@t{VARIABLE} @math{|} @t{LISTWISE}@} +@t{/PCOMPUTE} @t{&}@i{postcompute}@t{=EXPR(}@i{expression}@t{)} +@t{/PPROPERTIES} @t{&}@i{postcompute}@dots{} + [@t{LABEL=}@i{string}] + [@t{FORMAT=}[@i{summary} @i{format}]@dots{}] + [@t{HIDESOURCECATS=}@{@t{NO} @math{|} @t{YES}@} +@t{/WEIGHT VARIABLE=}@i{variable} +@t{/HIDESMALLCOUNTS COUNT=@i{count}} +@end display + +The following subcommands follow @code{TABLE} and apply only to the +previous @code{TABLE}. All of these subcommands are optional: + +@display +@t{/SLABELS} + [@t{POSITION=}@{@t{COLUMN} @math{|} @t{ROW} @math{|} @t{LAYER}@}] + [@t{VISIBLE=}@{@t{YES} @math{|} @t{NO}@}] +@t{/CLABELS} @{@t{AUTO} @math{|} @{@t{ROWLABELS}@math{|}@t{COLLABELS}@}@t{=}@{@t{OPPOSITE}@math{|}@t{LAYER}@}@} +@t{/CATEGORIES} @t{VARIABLES=}@i{variables} + @{@t{[}@i{value}@t{,} @i{value}@dots{}@t{]} + @math{|} [@t{ORDER=}@{@t{A} @math{|} @t{D}@}] + [@t{KEY=}@{@t{VALUE} @math{|} @t{LABEL} @math{|} @i{summary}@t{(}@i{variable}@t{)}@}] + [@t{MISSING=}@{@t{EXCLUDE} @math{|} @t{INCLUDE}@}]@} + [@t{TOTAL=}@{@t{NO} @math{|} @t{YES}@} [@t{LABEL=}@i{string}] [@t{POSITION=}@{@t{AFTER} @math{|} @t{BEFORE}@}]] + [@t{EMPTY=}@{@t{INCLUDE} @math{|} @t{EXCLUDE}@}] +@t{/TITLES} + [@t{TITLE=}@i{string}@dots{}] + [@t{CAPTION=}@i{string}@dots{}] + [@t{CORNER=}@i{string}@dots{}] +@ignore @c not yet implemented +@t{/CRITERIA CILEVEL=}@i{percentage} +@t{/SIGTEST TYPE=CHISQUARE} + [@t{ALPHA=}@i{siglevel}] + [@t{INCLUDEMRSETS=}@{@t{YES} @math{|} @t{NO}@}] + [@t{CATEGORIES=}@{@t{ALLVISIBLE} @math{|} @t{SUBTOTALS}@}] +@t{/COMPARETEST TYPE=}@{@t{PROP} @math{|} @t{MEAN}@} + [@t{ALPHA=}@i{value}[@t{,} @i{value}]] + [@t{ADJUST=}@{@t{BONFERRONI} @math{|} @t{BH} @math{|} @t{NONE}@}] + [@t{INCLUDEMRSETS=}@{@t{YES} @math{|} @t{NO}@}] + [@t{MEANSVARIANCE=}@{@t{ALLCATS} @math{|} @t{TESTEDCATS}@}] + [@t{CATEGORIES=}@{@t{ALLVISIBLE} @math{|} @t{SUBTOTALS}@}] + [@t{MERGE=}@{@t{NO} @math{|} @t{YES}@}] + [@t{STYLE=}@{@t{APA} @math{|} @t{SIMPLE}@}] + [@t{SHOWSIG=}@{@t{NO} @math{|} @t{YES}@}] +@end ignore +@end display + +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. + +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}. + +@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. At least one must specify an axis expression. + +@menu +* CTABLES Categorical Variable Basics:: +* CTABLES Scalar Variable Basics:: +* CTABLES Overriding Measurement Level:: +@end menu + +@node CTABLES Categorical Variable Basics +@subsubsection Categorical 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, much like the output of the +@code{FREQUENCIES} command (@pxref{FREQUENCIES}): + +@example +CTABLES /TABLE=AgeGroup. +@end example +@psppoutput {ctables1} + +@noindent +Specifying a row and a column categorical variable yields a +crosstabulation, much like the output of the @code{CROSSTABS} command +(@pxref{CROSSTABS}): + +@example +CTABLES /TABLE=AgeGroup BY qns3a. +@end example +@psppoutput {ctables2} + +@noindent +The @samp{>} ``nesting'' operator nests multiple variables on a single +axis, e.g.: + +@example +CTABLES /TABLE qn105ba BY AgeGroup > qns3a. +@end example +@psppoutput {ctables3} + +@noindent +The @samp{+} ``stacking'' operator allows a single output table to +include multiple data analyses. With @samp{+}, @code{CTABLES} divides +the output table into multiple @dfn{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 +When @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 CTABLES Scalar Variable Basics +@subsubsection Scalar Variables + +For a categorical variable, @code{CTABLES} divides the table into a +cell per category. For a scalar variable, @code{CTABLES} instead +calculates a summary measure, by default the mean, of the values that +fall into a cell. For example, if the only variable specified is a +scalar variable, then the output is a single cell that holds the mean +of all of the data: + +@example +CTABLES /TABLE qnd1. +@end example +@psppoutput {ctables6} + +A scalar variable may nest with categorical variables. The following +example shows the mean age of survey respondents across gender and +language groups: + +@example +CTABLES /TABLE qns3a > qnd1 BY region. +@end example +@psppoutput {ctables7} + +The order of nesting of scalar and categorical variables affects table +labeling, but it does not affect the data displayed in the table. The +following example shows how the output changes when the nesting order +of the scalar and categorical variable are interchanged: + +@example +CTABLES /TABLE qnd1 > qns3a BY region. +@end example +@psppoutput {ctables8} + +Only a single scalar variable may appear in each section; that is, a +scalar variable may not nest inside a scalar variable directly or +indirectly. Scalar variables may only appear on one axis within +@code{TABLE}. + +@node CTABLES Overriding Measurement Level +@subsubsection Overriding Measurement Level + +By default, @code{CTABLES} uses a variable's measurement level to +decide whether to treat it as categorical or scalar. Variables +assigned the nominal or ordinal measurement level are treated as +categorical, and scalar variables are treated as scalar. + +When @pspp{} reads data from a file in an external format, such as a +text file, variables' measurement levels are often unknown. If +@code{CTABLES} runs when a variable has an unknown measurement level, +it makes an initial pass through the data to guess measurement levels +using the rules described earlier in this manual (@pxref{Measurement +Level}). Use the @code{VARIABLE LEVEL} command to set or change a +variable's measurement level (@pxref{VARIABLE LEVEL}). + +To treat a variable as categorical or scalar only for one use on +@code{CTABLES}, add @samp{[C]} or @samp{[S]}, respectively, after the +variable name. The following example shows the output when variable +@code{qn20} is analyzed as scalar (the default for its measurement +level) and as categorical: + +@example +CTABLES + /TABLE qn20 BY qns3a + /TABLE qn20 [C] BY qns3a. +@end example +@psppoutput {ctables9} + +@ignore +@node CTABLES Multiple Response Sets +@subsubheading Multiple Response Sets + +The @code{CTABLES} command does not yet support multiple response +sets. +@end ignore + +@node CTABLES Data Summarization +@subsection Data Summarization + +The @code{CTABLES} command allows the user to control how the data are +summarized with @dfn{summary specifications}, syntax that lists one or +more summary function names, optionally separated by commas, and which +are enclosed in square brackets following a variable name on the +@code{TABLE} subcommand. When all the variables are categorical, +summary specifications can be given for the innermost nested variables +on any one axis. When a scalar variable is present, only the scalar +variable may have summary specifications. + +The following example includes a summary specification for column and +row percentages for categorical variables, and mean and median for a +scalar variable: + +@example +CTABLES + /TABLE=qnd1 [MEAN, MEDIAN] BY qns3a + /TABLE=AgeGroup [COLPCT, ROWPCT] BY qns3a. +@end example +@psppoutput {ctables10} + +A summary specification may override the default label and format by +appending a string or format specification or both (in that order) to +the summary function name. For example: + +@example +CTABLES /TABLE=AgeGroup [COLPCT 'Gender %' PCT5.0, + ROWPCT 'Age Group %' PCT5.0] + BY qns3a. +@end example +@psppoutput {ctables11} + +@c TODO special CTABLES formats + +Parentheses provide a shorthand to apply summary specifications to +multiple variables. For example, both of these commands: + +@example +CTABLES /TABLE=AgeGroup[COLPCT] + qns1[COLPCT] BY qns3a. +CTABLES /TABLE=(AgeGroup + qns1)[COLPCT] BY qns3a. +@end example + +@noindent +produce the same output shown below: + +@psppoutput {ctables12} + +The following sections list the available summary functions. After +each function's name is given its default label and format. If no +format is listed, then the default format is the print format for the +variable being summarized. + +@menu +* CTABLES Summary Functions for Individual Cells:: +* CTABLES Summary Functions for Groups of Cells:: +* CTABLES Summary Functions for Adjusted Weights:: +* CTABLES Unweighted Summary Functions:: +@end menu + +@node CTABLES Summary Functions for Individual Cells +@subsubsection Summary Functions for Individual Cells + +This section lists the summary functions that consider only an +individual cell in @code{CTABLES}. Only one such summary function, +@code{COUNT}, may be applied to both categorical and scale variables: + +@table @asis +@item @code{COUNT} (``Count'', F40.0) +The sum of weights in a cell. + +If @code{CATEGORIES} for one or more of the variables in a table +include missing values (@pxref{CTABLES Per-Variable Category +Options}), then some or all of the categories for a cell might be +missing values. @code{COUNT} counts data included in a cell +regardless of whether its categories are missing. +@end table + +The following summary functions apply only to scale variables or +totals and subtotals for categorical variables. Be cautious about +interpreting the summary value in the latter case, because it is not +necessarily meaningful; however, the mean of a Likert scale, etc.@: +may have a straightforward interpreation. + +@table @asis +@item @code{MAXIMUM} (``Maximum'') +The largest value. + +@item @code{MEAN} (``Mean'') +The mean. + +@item @code{MEDIAN} (``Median'') +The median value. + +@item @code{MINIMUM} (``Minimum'') +The smallest value. + +@item @code{MISSING} (``Missing'') +Sum of weights of user- and system-missing values. + +@item @code{MODE} (``Mode'') +The highest-frequency value. Ties are broken by taking the smallest mode. + +@item @code{PTILE} @i{n} (``Percentile @i{n}'') +The @var{n}th percentile, where @math{0 @leq{} @var{n} @leq{} 100}. + +@item @code{RANGE} (``Range'') +The maximum minus the minimum. + +@item @code{SEMEAN} (``Std Error of Mean'') +The standard error of the mean. + +@item @code{STDDEV} (``Std Deviation'') +The standard deviation. + +@item @code{SUM} (``Sum'') +The sum. + +@item @code{TOTALN} (``Total N'', F40.0) +The sum of weights in a cell. + +For scale data, @code{COUNT} and @code{TOTALN} are the same. + +For categorical data, @code{TOTALN} counts missing values in excluded +categories, that is, user-missing values not in an explicit category +list on @code{CATEGORIES} (@pxref{CTABLES Per-Variable Category +Options}), or user-missing values excluded because +@code{MISSING=EXCLUDE} is in effect on @code{CATEGORIES}, or +system-missing values. @code{COUNT} does not count these. + +@item @code{VALIDN} (``Valid N'', F40.0) +The sum of valid count weights in included categories. + +@code{VALIDN} does not count missing values regardless of whether they +are in included categories via @code{CATEGORIES}. @code{VALIDN} does +not count valid values that are in excluded categories. + +@item @code{VARIANCE} (``Variance'') +The variance. +@end table + +@node CTABLES Summary Functions for Groups of Cells +@subsubsection Summary Functions for Groups of Cells + +These summary functions summarize over multiple cells within an area +of the output chosen by the user and specified as part of the function +name. The following basic @var{area}s are supported, in decreasing +order of size: + +@table @code +@item TABLE +A @dfn{section}. Stacked variables divide sections of the output from +each other. sections may span multiple layers. + +@item LAYER +A section within a single layer. + +@item SUBTABLE +A @dfn{subtable}, whose contents are the cells that pair an innermost +row variable and an innermost column variable within a single layer. +@end table + +The following shows how the output for the table expression @code{qn61 +> qn57 BY qnd7a > qn86 + qn64b BY qns3a}@footnote{This is not +necessarily a meaningful table, so for clarity variable labels are +omitted.} is divided up into @code{TABLE}, @code{LAYER}, and +@code{SUBTABLE} areas. Each unique value for Table ID is one section, +and similarly for Layer ID and Subtable ID. Thus, this output has two +@code{TABLE} areas (one for @code{qnd7a} and one for @code{qn64b}), +four @code{LAYER} areas (for those two variables, per layer), and 12 +@code{SUBTABLE} areas. +@psppoutput {ctables22} + +@code{CTABLES} also supports the following @var{area}s that further +divide a subtable or a layer within a section: + +@table @code +@item LAYERROW +@itemx LAYERCOL +A row or column, respectively, in one layer of a section. + +@item ROW +@itemx COL +A row or column, respectively, in a subtable. +@end table + +The following summary functions for groups of cells are available for +each @var{area} described above, for both categorical and scale +variables: + +@table @asis +@item @code{@i{area}PCT} or @code{@i{area}PCT.COUNT} (``@i{Area} %'', PCT40.1) +A percentage of total counts within @var{area}. + +@item @code{@i{area}PCT.VALIDN} (``@i{Area} Valid N %'', PCT40.1) +A percentage of total counts for valid values within @var{area}. + +@item @code{@i{area}PCT.TOTALN} (``@i{Area} Total N %'', PCT40.1) +A percentage of total counts for all values within @var{area}. +@end table + +Scale variables and totals and subtotals for categorical variables may +use the following additional group cell summary function: + +@table @asis +@item @code{@i{area}PCT.SUM} (``@i{Area} Sum %'', PCT40.1) +Percentage of the sum of the values within @var{area}. +@end table + +@node CTABLES Summary Functions for Adjusted Weights +@subsubsection Summary Functions for Adjusted Weights + +If the @code{WEIGHT} subcommand specified an adjustment weight +variable, then the following summary functions use its value instead +of the dictionary weight variable. Otherwise, they are equivalent to +the summary function without the @samp{E}-prefix: + +@itemize @bullet +@item +@code{ECOUNT} (``Adjusted Count'', F40.0) + +@item +@code{ETOTALN} (``Adjusted Total N'', F40.0) + +@item +@code{EVALIDN} (``Adjusted Valid N'', F40.0) +@end itemize + +@node CTABLES Unweighted Summary Functions +@subsubsection Unweighted Summary Functions + +The following summary functions with a @samp{U}-prefix are equivalent +to the same ones without the prefix, except that they use unweighted +counts: + +@itemize @bullet +@item +@code{UCOUNT} (``Unweighted Count'', F40.0) + +@item +@code{U@i{area}PCT} or @code{U@i{area}PCT.COUNT} (``Unweighted @i{Area} %'', PCT40.1) + +@item +@code{U@i{area}PCT.VALIDN} (``Unweighted @i{Area} Valid N %'', PCT40.1) + +@item +@code{U@i{area}PCT.TOTALN} (``Unweighted @i{Area} Total N %'', PCT40.1) + +@item +@code{UMEAN} (``Unweighted Mean'') + +@item +@code{UMEDIAN} (``Unweighted Median'') + +@item +@code{UMISSING} (``Unweighted Missing'') + +@item +@code{UMODE} (``Unweight Mode'') + +@item +@code{U@i{area}PCT.SUM} (``Unweighted @i{Area} Sum %'', PCT40.1) + +@item +@code{UPTILE} @i{n} (``Unweighted Percentile @i{n}'') + +@item +@code{USEMEAN} (``Unweighted Std Error of Mean'') + +@item +@code{USTDDEV} (``Unweighted Std Deviation'') + +@item +@code{USUM} (``Unweighted Sum'') + +@item +@code{UTOTALN} (``Unweighted Total N'', F40.0) + +@item +@code{UVALIDN} (``Unweighted Valid N'', F40.0) + +@item +@code{UVARIANCE} (``Unweighted Variance'', F40.0) +@end itemize + +@node CTABLES Statistics Positions and Labels +@subsection Statistics Positions and Labels + +@display +@t{/SLABELS} + [@t{POSITION=}@{@t{COLUMN} @math{|} @t{ROW} @math{|} @t{LAYER}@}] + [@t{VISIBLE=}@{@t{YES} @math{|} @t{NO}@}] +@end display + +The @code{SLABELS} subcommand controls the position and visibility of +summary statistics for the @code{TABLE} subcommand that it follows. + +@code{POSITION} sets the axis on which summary statistics appear. +With @t{POSITION=COLUMN}, which is the default, each summary statistic +appears in a column. For example: + +@example +CTABLES /TABLE=qnd1 [MEAN, MEDIAN] BY qns3a. +@end example +@psppoutput {ctables13} + +@noindent +With @t{POSITION=ROW}, each summary statistic appears in a row, as +shown below: + +@example +CTABLES /TABLE=qnd1 [MEAN, MEDIAN] BY qns3a /SLABELS POSITION=ROW. +@end example +@psppoutput {ctables14} + +@noindent +@t{POSITION=LAYER} is also available to place each summary statistic in +a separate layer. + +Labels for summary statistics are shown by default. Use +@t{VISIBLE=NO} to suppress them. Because unlabeled data can cause +confusion, it should only be considered if the meaning of the data is +evident, as in a simple case like this: + +@example +CTABLES /TABLE=AgeGroup [TABLEPCT] /SLABELS VISIBLE=NO. +@end example +@psppoutput {ctables15} + +@node CTABLES Category Label Positions +@subsection Category Label Positions + +@display +@t{/CLABELS} @{@t{AUTO} @math{|} @{@t{ROWLABELS}@math{|}@t{COLLABELS}@}@t{=}@{@t{OPPOSITE}@math{|}@t{LAYER}@}@} +@end display + +The @code{CLABELS} subcommand controls the position of category labels +for the @code{TABLE} subcommand that it follows. By default, or if +@t{AUTO} is specified, category labels for a given variable nest +inside the variable's label on the same axis. For example, the +command below results in age categories nesting within the age group +variable on the rows axis and gender categories within the gender +variable on the columns axis: + +@example +CTABLES /TABLE AgeGroup BY qns3a. +@end example +@psppoutput {ctables16} + +@t{ROWLABELS=OPPOSITE} or @t{COLLABELS=OPPOSITE} move row or column +variable category labels, respectively, to the opposite axis. The +setting affects only the innermost variable on the given axis. For +example: + +@example +CTABLES /TABLE AgeGroup BY qns3a /CLABELS ROWLABELS=OPPOSITE. +CTABLES /TABLE AgeGroup BY qns3a /CLABELS COLLABELS=OPPOSITE. +@end example +@psppoutput {ctables17} + +@t{ROWLABELS=LAYER} or @t{COLLABELS=LAYER} move the innermost row or +column variable category labels, respectively, to the layer axis. + +Only one axis's labels may be moved, whether to the opposite axis or +to the layer axis. + +@c TODO Moving category labels for stacked variables + +@subsubheading Effect on Summary Statistics + +@code{CLABELS} primarily affects the appearance of tables, not the +data displayed in them. However, @code{CTABLES} can affect the values +displayed for statistics that summarize areas of a table, since it can +change the definitions of these areas. + +For example, consider the following syntax and output: + +@example +CTABLES /TABLE AgeGroup BY qns3a [ROWPCT, COLPCT]. +@end example +@psppoutput {ctables23} + +@noindent +Using @code{COLLABELS=OPPOSITE} changes the definitions of rows and +columns, so that column percentages display what were previously row +percentages and the new row percentages become meaningless (because +there is only one cell per row): + +@example +CTABLES + /TABLE AgeGroup BY qns3a [ROWPCT, COLPCT] + /CLABELS COLLABELS=OPPOSITE. +@end example +@psppoutput {ctables24} + +@node CTABLES Per-Variable Category Options +@subsection Per-Variable Category Options + +@display +@t{/CATEGORIES} @t{VARIABLES=}@i{variables} + @{@t{[}@i{value}@t{,} @i{value}@dots{}@t{]} + @math{|} [@t{ORDER=}@{@t{A} @math{|} @t{D}@}] + [@t{KEY=}@{@t{VALUE} @math{|} @t{LABEL} @math{|} @i{summary}@t{(}@i{variable}@t{)}@}] + [@t{MISSING=}@{@t{EXCLUDE} @math{|} @t{INCLUDE}@}]@} + [@t{TOTAL=}@{@t{NO} @math{|} @t{YES}@} [@t{LABEL=}@i{string}] [@t{POSITION=}@{@t{AFTER} @math{|} @t{BEFORE}@}]] + [@t{EMPTY=}@{@t{INCLUDE} @math{|} @t{EXCLUDE}@}] +@end display + +The @code{CATEGORIES} subcommand specifies, for one or more +categorical variables, the categories to include and exclude, the sort +order for included categories, and treatment of missing values. It +also controls the totals and subtotals to display. It may be +specified any number of times, each time for a different set of +variables. @code{CATEGORIES} applies to the table produced by the +@code{TABLE} subcommand that it follows. + +@code{CATEGORIES} does not apply to scalar variables. + +@t{VARIABLES} is required and must list the variables for the subcommand +to affect. + +There are two way to specify the Categories to include and their sort +order: + +@table @asis +@item Explicit categories. +@anchor{CTABLES Explicit Category List} +To explicitly specify categories to include, list the categories +within square brackets in the desired sort order. Use spaces or +commas to separate values. Categories not covered by the list are +excluded from analysis. + +Each element of the list takes one of the following forms: + +@table @t +@item @i{number} +@itemx '@i{string}' +A numeric or string category value, for variables that have the +corresponding type. + +@item '@i{date}' +@itemx '@i{time}' +A date or time category value, for variables that have a date or time +print format. + +@item @i{min} THRU @i{max} +@itemx LO THRU @i{max} +@itemx @i{min} THRU HI +A range of category values, where @var{min} and @var{max} each takes +one of the forms above, in increasing order. + +@item MISSING +All user-missing values. (To match individual user-missing values, +specify their category values.) + +@item OTHERNM +Any non-missing value not covered by any other element of the list +(regardless of where @t{OTHERNM} is placed in the list). + +@item &@i{postcompute} +A computed category name (@pxref{CTABLES Computed Categories}). +@end table + +Additional forms, described later, allow for subtotals. +If multiple elements of the list cover a given category, the last one +in the list takes precedence. + +@item Implicit categories. +Without an explicit list of categories, @pspp{} sorts +categories automatically. + +The @code{KEY} setting specifies the sort key. By default, or with +@code{KEY=VALUE}, categories are sorted by default. Categories may +also be sorted by value label, with @code{KEY=LABEL}, or by the value +of a summary function, e.g.@: @code{KEY=COUNT}. +@ignore @c Not yet implemented +For summary functions, a variable name may be specified in +parentheses, e.g.@: @code{KEY=MAXIUM(qnd1)}, and this is required for +functions that apply only to scalar variables. The @code{PTILE} +function also requires a percentage argument, e.g.@: +@code{KEY=PTILE(qnd1, 90)}. Only summary functions used in the table +may be used, except that @code{COUNT} is always allowed. +@end ignore + +By default, or with @code{ORDER=A}, categories are sorted in ascending +order. Specify @code{ORDER=D} to sort in descending order. + +User-missing values are excluded by default, or with +@code{MISSING=EXCLUDE}. Specify @code{MISSING=INCLUDE} to include +user-missing values. The system-missing value is always excluded. +@end table + +@subsubheading Totals and Subtotals + +@code{CATEGORIES} also controls display of totals and subtotals. +Totals are not displayed with @code{TOTAL=NO}, which is also the +default. Specify @code{TOTAL=YES} to display a total. By default, +the total is labeled ``Total''; use @code{LABEL="@i{label}"} to +override it. + +Subtotals are also not displayed by default. To add one or more +subtotals, use an explicit category list and insert @code{SUBTOTAL} or +@code{HSUBTOTAL} in the position or positions where the subtotal +should appear. With @code{SUBTOTAL}, the subtotal becomes an extra +row or column or layer; @code{HSUBTOTAL} additionally hides the +categories that make up the subtotal. Either way, the default label +is ``Subtotal'', use @code{SUBTOTAL="@i{label}"} or +@code{HSUBTOTAL="@i{label}"} to specify a custom label. + +By default, or with @code{POSITION=AFTER}, totals are displayed in the +output after the last category and subtotals apply to categories that +precede them. With @code{POSITION=BEFORE}, totals come before the +first category and subtotals apply to categories that follow them. + +Only categorical variables may have totals and subtotals. Scalar +variables may be ``totaled'' indirectly by enabling totals and +subtotals on a categorical variable within which the scalar variable is +summarized. + +@c TODO Specifying summaries for totals and subtotals + +@subsubheading Categories Without Values + +Some categories might not be included in the data set being analyzed. +For example, our example data set has no cases in the ``15 or +younger'' age group. By default, or with @code{EMPTY=INCLUDE}, +@pspp{} includes these empty categories in output tables. To exclude +them, specify @code{EMPTY=EXCLUDE}. + +For implicit categories, empty categories potentially include all the +values with value labels for a given variable; for explicit +categories, they include all the values listed individually and all +values with value labels that are covered by ranges or @code{MISSING} +or @code{OTHERNM}. + +@node CTABLES Titles +@subsection Titles + +@display +@t{/TITLES} + [@t{TITLE=}@i{string}@dots{}] + [@t{CAPTION=}@i{string}@dots{}] + [@t{CORNER=}@i{string}@dots{}] +@end display + +@c TODO Describe substitution variables + +The @code{TITLES} subcommand sets the title, caption, and corner text +for the table output for the previous @code{TABLE} subcommand. The +title appears above the table, the caption below the table, and the +corner text appears in the table's upper left corner. By default, the +title is ``Custom Tables'' and the caption and corner text are empty. +With some table output styles, the corner text is not displayed. + +@node CTABLES Table Formatting +@subsection Table Formatting + +@display +@t{/FORMAT} + [@t{MINCOLWIDTH=}@{@t{DEFAULT} @math{|} @i{width}@}] + [@t{MAXCOLWIDTH=}@{@t{DEFAULT} @math{|} @i{width}@}] + [@t{UNITS=}@{@t{POINTS} @math{|} @t{INCHES} @math{|} @t{CM}@}] + [@t{EMPTY=}@{@t{ZERO} @math{|} @t{BLANK} @math{|} @i{string}@}] + [@t{MISSING=}@i{string}] +@end display + +The @code{FORMAT} subcommand, which must precede the first +@code{TABLE} subcommand, controls formatting for all the output +tables. @code{FORMAT} and all of its settings are optional. + +Use @code{MINCOLWIDTH} and @code{MAXCOLWIDTH} to control the minimum +or maximum width of columns in output tables. By default, with +@code{DEFAULT}, column width varies based on content. Otherwise, +specify a number for either or both of these settings. If both are +specified, @code{MAXCOLWIDTH} must be greater than or equal to +@code{MINCOLWIDTH}. The default unit, or with @code{UNITS=POINTS}, is +points (1/72 inch), or specify @code{UNITS=INCHES} to use inches or +@code{UNITS=CM} for centimeters. + +By default, or with @code{EMPTY=ZERO}, zero values are displayed in +their usual format. Use @code{EMPTY=BLANK} to use an empty cell +instead, or @code{EMPTY="@i{string}"} to use the specified string. + +By default, missing values are displayed as @samp{.}, the same as in +other tables. Specify @code{MISSING="@i{string}"} to instead use a +custom string. + +@node CTABLES Display of Variable Labels +@subsection Display of Variable Labels + +@display +@t{/VLABELS} + @t{VARIABLES=}@i{variables} + @t{DISPLAY}=@{@t{DEFAULT} @math{|} @t{NAME} @math{|} @t{LABEL} @math{|} @t{BOTH} @math{|} @t{NONE}@} +@end display + +The @code{VLABELS} subcommand, which must precede the first +@code{TABLE} subcommand, controls display of variable labels in all +the output tables. @code{VLABELS} is optional. It may appear +multiple times to adjust settings for different variables. + +@code{VARIABLES} and @code{DISPLAY} are required. The value of +@code{DISPLAY} controls how variable labels are displayed for the +variables listed on @code{VARIABLES}. The supported values are: + +@table @code +@item DEFAULT +Use the setting from @code{SET TVARS} (@pxref{SET TVARS}). + +@item NAME +Show only a variable name. + +@item LABEL +Show only a variable label. + +@item BOTH +Show variable name and label. + +@item NONE +Show nothing. +@end table + +@node CTABLES Missing Value Treatment +@subsection Missing Value Treatment + +@display +@t{/SMISSING} @{@t{VARIABLE} @math{|} @t{LISTWISE}@} +@end display + +The @code{SMISSING} subcommand, which must precede the first +@code{TABLE} subcommand, controls treatment of missing values for +scalar variables in producing all the output tables. @code{SMISSING} +is optional. + +With @code{SMISSING=VARIABLE}, which is the default, missing values +are excluded on a variable-by-variable basis. With +@code{SMISSING=LISTWISE}, when stacked scalar variables are nested +together with a categorical variable, a missing value for any of the +scalar variables causes the case to be excluded for all of them. + +As an example, consider the following dataset, in which @samp{x} is a +categorical variable and @samp{y} and @samp{z} are scale: + +@psppoutput{ctables18} + +@noindent +With the default missing-value treatment, @samp{x}'s mean is 20, based +on the values 10, 20, and 30, and @samp{y}'s mean is 50, based on 40, +50, and 60: + +@example +CTABLES /TABLE (y + z) > x. +@end example +@psppoutput{ctables19} + +@noindent +By adding @code{SMISSING=LISTWISE}, only cases where @samp{y} and +@samp{z} are both non-missing are considered, so @samp{x}'s mean +becomes 15, as the average of 10 and 20, and @samp{y}'s mean becomes +55, the average of 50 and 60: + +@example +CTABLES /SMISSING LISTWISE /TABLE (y + z) > x. +@end example +@psppoutput{ctables20} + +@noindent +Even with @code{SMISSING=LISTWISE}, if @samp{y} and @samp{z} are +separately nested with @samp{x}, instead of using a single @samp{>} +operator, missing values revert to being considered on a +variable-by-variable basis: + +@example +CTABLES /SMISSING LISTWISE /TABLE (y > x) + (z > x). +@end example +@psppoutput{ctables21} + +@node CTABLES Computed Categories +@subsection Computed Categories + +@display +@t{/PCOMPUTE} @t{&}@i{postcompute}@t{=EXPR(}@i{expression}@t{)} +@end display + +@dfn{Computed categories}, also called @dfn{postcomputes}, are +categories created using arithmetic on categories obtained from the +data. The @code{PCOMPUTE} subcommand defines computed categories, +which can then be used in two places: on @code{CATEGORIES} within an +explicit category list (@pxref{CTABLES Explicit Category List}), and on +the @code{PPROPERTIES} subcommand to define further properties for a +given postcompute. + +@code{PCOMPUTE} must precede the first @code{TABLE} command. It is +optional and it may be used any number of times to define multiple +postcomputes. + +Each @code{PCOMPUTE} defines one postcompute. Its syntax consists of +a name to identify the postcompute as a @pspp{} identifier prefixed by +@samp{&}, followed by @samp{=} and a postcompute expression enclosed +in @code{EXPR(@dots{})}. A postcompute expression consists of: + +@table @t +@item [@i{category}] +This form evaluates to the summary statistic for @i{category}, e.g.@: +@code{[1]} evaluates to the value of the summary statistic associated +with category 1. The @i{category} may be a number, a quoted string, +or a quoted time or date value. All of the categories for a given +postcompute must have the same form. The category must appear in all +the @code{CATEGORIES} list in which the postcompute is used. + +@item [@i{min} THRU @i{max}] +@itemx [LO THRU @i{max}] +@itemx [@i{min} THRU HI] +@itemx MISSING +@itemx OTHERNM +These forms evaluate to the summary statistics for a category +specified with the same syntax, as described in previous section +(@pxref{CTABLES Explicit Category List}). The category must appear in +all the @code{CATEGORIES} list in which the postcompute is used. + +@item SUBTOTAL +The summary statistic for the subtotal category. This form is allowed +only if the @code{CATEGORIES} lists that include this postcompute have +exactly one subtotal. + +@item SUBTOTAL[@i{index}] +The summary statistic for subtotal category @i{index}, where 1 is the +first subtotal, 2 is the second, and so on. This form may be used for +@code{CATEGORIES} lists with any number of subtotals. + +@item TOTAL +The summary statistic for the total. The @code{CATEGORIES} lsits that +include this postcompute must have a total enabled. + +@item @i{a} + @i{b} +@itemx @i{a} - @i{b} +@itemx @i{a} * @i{b} +@itemx @i{a} / @i{b} +@itemx @i{a} ** @i{b} +These forms perform arithmetic on the values of postcompute +expressions @i{a} and @i{b}. The usual operator precedence rules +apply. + +@item @i{number} +Numeric constants may be used in postcompute expressions. + +@item (@i{a}) +Parentheses override operator precedence. +@end table + +A postcompute is not associated with any particular variable. +Instead, it may be referenced within @code{CATEGORIES} for any +suitable variable (e.g.@: only a string variable is suitable for a +postcompute expression that refers to a string category, only a +variable with subtotals for an expression that refers to subtotals, +@dots{}). + +Normally a named postcompute is defined only once, but if a later +@code{PCOMPUTE} redefines a postcompute with the same name as an +earlier one, the later one take precedence. + +@node CTABLES Computed Category Properties +@subsection Computed Category Properties + +@display +@t{/PPROPERTIES} @t{&}@i{postcompute}@dots{} + [@t{LABEL=}@i{string}] + [@t{FORMAT=}[@i{summary} @i{format}]@dots{}] + [@t{HIDESOURCECATS=}@{@t{NO} @math{|} @t{YES}@} +@end display + +The @code{PPROPERTIES} subcommand, which must appear before +@code{TABLE}, sets properties for one or more postcomputes defined on +prior @code{PCOMPUTE} subcommands. The subcommand syntax begins with +the list of postcomputes, each prefixed with @samp{&} as specified on +@code{PCOMPUTE}. + +All of the settings on @code{PPROPERTIES} are optional. Use +@code{LABEL} to set the label shown for the postcomputes in table +output. The default label for a postcompute is the expression used to +define it. + +The @code{FORMAT} setting sets summary statistics and display formats +for the postcomputes. + +By default, or with @code{HIDESOURCECATS=NO}, categories referred to +by computed categories are displayed like other categories. Use +@code{HIDESOURCECATS=YES} to hide them. + +@node CTABLES Base Weight +@subsection Base Weight + +@display +@t{/WEIGHT VARIABLE=}@i{variable} +@end display + +The @code{WEIGHT} subcommand is optional and must appear before +@code{TABLE}. If it appears, it must name a numeric variable, known +as the @dfn{effective base weight} or @dfn{adjustment weight}. The +effective base weight variable stands in for the dictionary's weight +variable (@pxref{WEIGHT}), if any, in most calculations in +@code{CTABLES}. The only exceptions are the @code{COUNT}, +@code{TOTALN}, and @code{VALIDN} summary functions, which use the +dictionary weight instead. + +Weights obtained from the @pspp{} dictionary are rounded to the +nearest integer at the case level. Effective base weights are not +rounded. Regardless of the weighting source, @pspp{} does not analyze +cases with zero, missing, or negative effective weights. + +@node CTABLES Hiding Small Counts +@subsection Hiding Small Counts + +@display +@t{/HIDESMALLCOUNTS COUNT=@i{count}} +@end display + +The @code{HIDESMALLCOUNTS} subcommand is optional. If it specified, +then count values in output tables less than the value of @i{count} +are shown as @code{<@i{count}} instead of their true values. The +value of @i{count} must be an integer and must be at least 2. Case +weights are considered for deciding whether to hide a count. + @node FACTOR @section FACTOR @@ -1598,9 +2712,10 @@ arbitrary number of populations. It does not assume normality. The data to be compared are specified by @var{var_list}. 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}] are -ignored. +@var{upper} specify the valid range of @var{var}. +If @var{upper} is smaller than @var{lower}, the PSPP will assume their values +to be reversed. Any cases for which @var{var} falls outside +[@var{lower}, @var{upper}] are ignored. The mean rank of each group as well as the chi-squared value and significance of the test are printed.